Estimation Importance In Project Management Information Technology Essay

Estimation Importance In Project Management Information Technology Essay Objective of the report: The objective of this report is to investigate the use of Estimation of project parameters like project cost and time, in Project Management. The report starts with the definition of the estimation and its use for a successful project management. A brief description of project estimation process is explained in the report, along with the basic classification of the types of estimates that can be performed for a successful project management. The issues involved in estimating the project parameters in real-time are investigated in a detailed manner. Then critical evaluation of various estimation methods is performed. A complete analysis of the methods evaluated in the report is performed. Finally, the report is concluded with the suggestions on selecting a particular Project Estimation process for a successful Project Management. Importance of Estimation in project management: The four major parameters that control the software projects are time, requirements, resources (people, infrastructure/materials and money), and risks. This is one of the reasons why making good estimates of these variables like time and resources required for a project is very critical. But if the estimation is lower than the project needs it will affect the progress of the project due to the lack of enough time, money, infrastructure/materials, or people. At the same time even if the estimation is over estimated then the company will have to face losses due to the extra expenses or even if the project is sanctioned other projects dont go on since there is less to go around. For any successful project management, estimation is a vital part of project methodology. Estimation has numerous applications like justification of project which has to be applied in the initial stages of the project where in we need to anticipate the benefits which is compared with the costs incurred as well as to decipher comparisons and conclusions that has to be made with technical and functional teams involved in the project. The other additional applications of the estimation are to implement the disciplines required, to protect the resources required to deliver the project successfully, to ensure the support impact of the project is fully understood, to inform and improve the software development process. This document describes the techniques used to produce reliable estimates for the work required to complete projects and tasks. Estimation process: Definition: Project estimation is a process of forecasting or approximating the project parameters like cost, time, effort etc., for a successful completion of the project deliverables. Overview of the Estimation Process: The first point to be remembered about estimation is that it does not finish until the completion of project and is a process of a slow and gradual refinement. For many software projects a project manager can assist the team to create successful estimates by using sound techniques and understanding about what makes estimate more accurate. The team chosen to produce an estimate are typically drawn from IS, customers and/or service partners who have relevant experience of similar previous projects or tasks in the business area. When we want to start a project we need to know basic parameters required in advance like how long it will take, how many people it will require, how much effort it will require. In such cases it is hard to estimate because in many cases projects overrun or project go over budget. Always a good estimation practices keep the project on track and even can earn some time for the tricky, interesting areas. Our estimation process is based on three components: Expert judgement, Consultation with qualified experts from within business and service partners. This is supplemented, where required, by expert input  from software suppliers and consultants.   Experience,  i.e. comparison of the proposed project or task with previously completed work. Task Decomposition, i.e. decomposing the project into components, i.e. a Work Breakdown Structure, and estimating each component individually to produce an overall estimate. This will also reduce the chances of error occurrence. When to estimate: A rough estimate is needed at the initial stage of the project or probably even before the actual project starts. This is because, the final negotiations should be made with the customer, which needs the rough estimate of the cost, time and quality of the project. Also, Estimation is a process of gradual refinement. It should be performed in parallel with the project development, in several phases. Each estimate will be refined to give a converged estimate towards the end of the project. Estimation should be carried out until the completion of project deliverables. There are basically two approaches for estimating project parameters. They are; Top-down estimation approach Bottom-up estimation approach Top-down estimation approach: Top-down estimation approach is usually used at the initial stages of the project. This estimation is usually carried out by the top managers who have little knowledge of the processes involved in the completion of the project. The input to this estimation is either information or the experience of the manager carrying out the estimation. These top-down estimation methods are often used to evaluate the project proposal. In most cases, the best results can be achieved in estimation only when one used both top-down and bottom-up estimation methods. However, it is practically not possible to carry out bottom-up methods until the Work Breakdown Structure (WBS) are clearly defined. In such cases, top-down estimates are used until the WBS becomes available. There are many methods in top-down approach listed below: Consensus methods: This estimation method uses experience of a group of people to estimate the project parameters. This method involves project meetings, a place where these people can discuss, argue and finally come to a conclusion from their best guess estimate. The Delphi method comes under this category. Ratio methods: These estimation methods use ratios to estimate project times and costs. For example, in a construction work, the total cost of the project can be estimated by knowing the number of square feet. Likewise, a software project is estimated by its complexity and its features. Approximation methods: This estimation method is very useful when the project to be estimated is closely related to any of the previous projects in terms of its features and costs. By using the historical data of the estimates, good estimates can be approximated with very little effort. Function point methods: Many software projects are usually estimated using weighted macro variables called function points. Function points can be number of inputs, number of outputs, number of inquiries, number of data files, and number of interfaces. These function points are weighted again with a complexity level and summed up to get the total cost or duration estimates of the project. Bottom-up estimation approach: Top-down estimation approach can usually be put in practice once the project is defined or once there is some progress in the project. This means, this estimation is more into work package level, which are responsible for low-cost estimates and efficient methods. It is often recommended that this estimation is usually carried out by people most knowledgeable about the estimate needed. The cost, time, resource estimates from the work packages can be checked with the associated accounts to major deliverables. Also, these estimates in later stages can be consolidated into phased networks, resource schedules, and budgets that used for control. Additionally, customer will get an opportunity to compare the low-cost, efficient method with any imposed restrictions, using bottom-up approach. There are many methods in top-down approach listed below: Template methods: If the project to be estimated is similar to any of the past projects, then estimates of the past projects can be used as starting point estimates for the new project. This is similar to approximation estimation in top-down approach. Parametric procedures: These parametric procedures are same like ratio methods in top-down approach. However, here the parametric procedures are applied on specific tasks. Detailed estimates for WBS work packages: This is usually most reliable method of all estimation methods. The reason for this is that here the estimates are performed by people responsible for the work packages in Work Breakdown Structure. These people have prior knowledge or experience upon the tasks they perform specified in WBS, because of which the estimates are usually most reliable. In addition to the top-down and bottom-up approaches, there is another kind of estimating which is a hybrid of the above two approaches. This is called as Phase Estimating. When there is unusual amount of uncertainty is surrounded by the project, people go for phase estimating. In this approach, two-estimate system is used over the life-cycle of the project. The whole project is initially divided into phases. Then a detailed estimate is developed for the immediate phase, and a macro-estimate is mode for the remaining phases of the project. Difficulties in Estimation: There are two major cases where Estimation problems almost always boil down to estimates that are either too high or too low. Padded estimates, where the team members intentionally over estimates in order to give themselves extra time to work, are a chronic source of estimates that are too high. Other case arises when senior managers give unrealistic deadlines that are a chronic source of estimates that are too low. Both the cases can lead to morale problems. Estimation Tools: Software tools are very important for estimation. Estimation tools are the software packages implemented using any of the estimation methods as its algorithm, to make project managers life easy. These estimation tools help from skipping important tasks in a method. These tools are useful to organise, update and store the results of the estimates. Also, Estimation Tools are useful to: Estimate project size using Function Points or other metrics. Derive effort and schedule from the project estimates using various algorithms and techniques. Perform analysis with staffing, duration etc. and appreciate how realistic they are. Produce and update results like Gantt charts and other tables easily. Maintain and exploit a database of historic data. Import data from other projects run in organisations with which you have no connection. However, one should very carefully select the estimation tools for a particular project. Principle: Required functional capabilities of estimation tools should match the needs and desired capabilities specific to the project. In selecting an estimation tool, one should match the available tools with the overall requirements of the project. In general, estimation tools should: Be very adaptive to any projects development environment, so that one can customize the tool according to the project needs. Be comparatively easy to understand, learn and use. Be able to produce some early project estimates without waiting for the whole project to be completely defined designed. Be able to provide estimates for different phases and activities in the project, if it is classified so. Understand and support wide range of languages and applications, as it is really important for a tool to provide estimates specific to the applications. Be able to provide accurate schedule estimates, whose purpose is not only to predict task completion given task sequence and available resources, but also to establish starting and ending dates for the associated work packages and life-cycle phases. Be able to provide maintenance estimates separately, which includes correcting errors, modifying the software to accommodate changes in requirements, and extending and enhancing software performance. Critical evaluation of the estimation tools: There are many tools in the market for project estimation. However, I am investigating a few and very efficient tools in the current market. PROBE: The name PROBE is derived from Proxy Based Estimating, introduced by Watts Humphrey (of the Software Engineering Institute at Carnegie Mellon University). Principle: If a component being built is similar to one built previously, then the effort it takes would be about the same as it did in the past. It mainly helps individual software engineers monitor, test, and improve their own work. Each component in the database is assigned a type (calculation, data, logic, etc.) and a size (from very small to very large). Also, a database is used to store history of size and effort details of these individual components. Later on, when a new project must be estimated, it is broken down into tasks that correspond to these types and sizes. A formula based on linear regression is used to calculate the estimate for each task. Additional information on PROBE can be found in A Discipline for Software Engineering by Watts Humphrey (Addison Wesley, 1994). COCOMO: The COCOMO is the most used estimation tool in the market for cost and schedule estimating. The COCOMO is derived from Constructive Cost Model, developed by Barry Boehm in the early 1980s. Principle: The model developed empirically by running a study of many software development projects and statistically analyzing their results. There by developing a database of the analysed details. Boehm developed COCOMO empirically by running a study of 63 software development projects and statistically analyzing their results. COCOMO II was developed in the 1990s as an updated version for modern development life cycles, and it is based on a broader set of data. The COCOMO calculation incorporates 15 cost drivers, variables that must be provided as input for a model that is based on the results of those studied projects. These variables cover software, computer, personnel, and project attributes. The output of the model is a set of size and effort estimates that can be developed into a project schedule. Additional information on COCOMO can be found in Software Cost Estimation with Cocomo II by Barry Boehm et al. (Prentice Hall PTR, 2000). The Planning Game: The Planning Game is the software project planning method from Extreme Programming (XP), a lightweight development methodology developed by Kent Beck in the 1990s at Chrysler. It is a method used to manage the negotiation between the engineering team (Development) and the stakeholders (Business). It gains some emotional distance from the planning process by treating it as a game, where the playing pieces are user stories written on index cards and the goal is to assign value to stories and put them into production over time. Unlike PROBE, COCOMO and Delphi, the Planning Game does not require a documented description of the scope of the project to be estimated. Rather, it is a full planning process that combines estimation with identifying the scope of the project and the tasks required to complete the software. Like much of XP, the planning process is highly iterative. The scope is established by having Development and Business work together to interactively write the stories. Then, each story is given an estimate of 1, 2, or 3 weeks. Stories that are larger than that are split up into multiple iterations. Business is given an opportunity to steer the project between iterations. The estimates themselves are created by the programmers, based on the stories that are created. Finally, commitments are agreed upon. This is repeated until the next iteration of the project is planned. Additional information on the Planning Game can be found in Extreme Programming Explained by Kent Beck (Addison Wesley, 2000). Critical analysis: In order to have the best estimates of a project, make some rough top-down estimates initially, develop the WBS, using which make bottom-up estimates, and develop schedules and estimates and finally, reconcile the differences between top-down and bottom-up approaches. Also for ideal results, the project manager should allow some time to carry out top-down and bottom-up estimates, there by reliable estimates can be offered to the customer. This will in turn reduce the false expectations for stakeholders. Phase estimation approach is much useful in the projects, whose final nature (shape, size, features) is highly uncertain. COCOMO II can be used for the following major decision situations Making investment or other financial decisions involving a software development effort Setting project budgets and schedules as a basis for planning and control Deciding on or negotiating tradeoffs among software cost, schedule, functionality, performance or quality factors Making software cost and schedule risk management decisions Deciding which parts of a software system to develop, reuse, lease, or purchase Making legacy software inventory decisions: what parts to modify, phase out, outsource, etc Setting mixed investment strategies to improve organizations software capability, via reuse, tools, process maturity, outsourcing, etc Deciding how to implement a process improvement strategy, such as that provided in the SEI CMM Conclusion:

The Psychology of Serial Killers Essay -- Psychological Murder murdere

The Psychology of Serial Killers Many things today confuse, yet enthrall the masses. War, murder, medical science, incredible rescues, all things you would see on The History Channel. There is another topic that is also made into documentaries however, serial killers. Dark twisted people that commit multiple murders are of interest to the population, but what caused them to be this way. What horrible tragic set of events could twist a man to murder one or many people. Could Schizophrenia, psychopathy, or sociopathy? Many people have researched this topic and believe that childhood trauma, heavy drugs during the growing phase of life, as well as many other things have twisted the minds of men such as Jeffery Dahmer, Charles Manson, John Wayne Gacy, and David Berkowitz. Many say that their actions were preventable but many other believe that the warning signs were present and that their behavior could have been modified long before the murders began.   Ã‚  Ã‚  Ã‚  Ã‚  The triad is the name given to the set of characteristic that serials killers are evident of in their youth. The ?typical? serial killer is a sociopath or psychopath that during childhood was subject to three diagnoses: fire starting (pyromania), prolonged bed-wetting, and animal torture. All of these things correlate to a phase in life in which the young person is curious of certain things new to them. Most children grow out of their interest in fire starting when they first get burnt and bed-wetting when they progress out of the same phase. Animal torture is slightly different. Many children enjoy pulling the wings off a fly, or the legs off of other insects however grow up into quite productive members of society. Some children are enthused by larger animals. Jeffrey Dahmer was enthused originally by fish. He would gut them and inspect their organs to examined how they worked. Curiosity being the main reason for his actions, he would also nail frogs to trees an d collect animals that had been run over by cars. Dahmer was less than characteristic in his choice of animals, the most popular victim being cats. Be it throwing felines from high elevations to watch them ?splat? as explained by Ian Brady the Moors Murderer, gutting them and watching how far they can run after, or burying them alive cats have become the general choice among serial killers-to-be. The A to Z encyclopedia of Serial Killers men... ...for these people should be higher. If that cannot be done then in modern day with all the screening at schools for eye sight problems and back problems could psychological tests also be run to screen for the triad or other such symptoms that lead to murder. Can serial killers be medicated and dissuaded from their future murders before they occur? What can be done in order to dissuade murder in modern society? That is what the world needs now.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Works Cited Newton, Michael. The Encyclopedia of Serial Killers. New York: Checkmark Books, 2000. Schechter, Harold, and David Everitt. The A to Z Encyclopedia of Serial Killers. New York: Pocket Books, 1997. Douglas, John, and Mark Olshaker; Mind Hunter: Inside the FBI's Elite Serial Crime Unit. New York, Pocket Books, 1997.  Ã‚  Ã‚  Ã‚  Ã‚   What Makes Serial Killers Tick?. Shirley Lynn Scott. From http://www.crimelibrary.com/about/authors/scott/index.html?sect=1 Angels of Mercy; The Dark Side. Rick Hampton Dec. 2003 Antisocial Personality Disorder: Treatment. Phillip W. Long M.D. Jan 1990. Psychopathic Sexual Sadists The Psychology and Psychodynamics of Serial Killers. Vernon J. Gerberth. April 1995.   Ã‚  Ã‚  Ã‚  Ã‚  

Physical Security Essay

INTRODUCTION. Physical security starts with a rather simple basic premise; those who do not belong on your institution’s property should be excluded from your institution. This may happen in three often interrelated ways: when those who do not belong are identified, stopped and denied admission, when those who do not belong are denied admission by a physical device, such as a locked door. When those who do not belong are denied admission because they decide that your institution is too difficult to enter and thus they do note entry. This section will consider the various methods of excluding those who do not belong: access control, key control and locks, protective devices and alarms, windows and doors, fencing and gates, protective lighting, general deterrence. PHYSICAL SECURITY AND CRIME PREVENTION AND CONTROL Access Control Access control means that, when your facility is open, no visitor, delivery service person or unknown individual is able to enter your facility without being both observed directly or indirectly. Several techniques to accomplish that goal may include any or all of the following. Security Desk A security desk should be setup in them in lobby of each building which has an open-access or open-door policy. A sign-in and outlet supervised by an employee who validates identification prior to allowing visitors to proceed into the building, is highly advisable. Most supermarkets, five star hotels, foreign embassies, parliament buildings and major organizations have this measure in place in order to monitor the staff and clients as they come in and out to ascertain no harmful contrabands are sneaked in or pilferage of equipments and other relevant materials from the organization. When entering a building like I&M where Standard Group have offices or Nation Centre where NTV is housed you have to produce your National ID, register your name, office and purpose of your visit then insured with a visitors pass in order to gain access to the premises. Monitored Entrances Ideally, an institution should have a single entrance only, monitored by staff personnel and equipped with an intercom system for communicating with anyone who comes to the door. Simply, an open door policy does not mean that every door need be left open and unlocked. You realize that hospitals, police headquarters, military barracks among others have personnel who are assigned on daily basis to check and verify individuals and motor vehicles that come in or leave the premises. Its purpose is to deter criminals and take note of every visitor for purposes of accountability when things go amiss. When entering the Times Tower where the Kenya Revenue Authority is housed, the security guards at the gate verifies visitors by their National Identity cards and or travelers passport and then a separate group of guards checks for any harmful materials by use of metal detectors. Visitors At no time should visitors be allowed to roam freely through your property unescorted or without being observed. That is especially true for individuals who expect to work on your most sensitive systems such as burglar alarms, fire alarms, communication systems or computers. Special diligence should be applied to those individuals when they visit your institution even if they are legitimate. For larger institutions, certain areas should be considered off-limits to all but authorized personnel. Allowing visitors free access to your facility does not mean that they should be allowed to go anywhere e.g. into restricted areas such as office spaces or that they should be given a sense that their actions are entirely unnoticed by the institution’s personnel. Some premises require having out of bound locations i.e. military barracks, production factories railway stations, air and seaports for purposes of security. Thus visitor should only be directed to designated zones only. Military barracks have their armories protected while airports have garages and main control rooms protected for security purposes. Employee Photo Identification Cards and Badges All employees should have and wear identification. Such badges make identification of non-employees immediate. Moreover, such cards will not only enable visitors to immediately identify those who work in an institution but will psychologically help employees understand that they are part of their agency’s security team. Photo identification should only be provided with accompanying education regarding their care, the procedure to be followed if they are lost, as well as the manner in which employees should approach unknown individuals. Creating ID badges requires thought. Cards should have clear pictures along with the employee’s name. The institution’s name should not necessarily be placed on the card. In any event, employees should be instructed that their card should be prominently worn while in the building and, for their own safety, kept from view when away from the building. In major hospitals like Nairobi hospital, Matter hospital among others every employee has a job ID which enables them access to all areas and distinguish them from patients, this reduces the chances of an admitted patient running away from the premise without paying the medical bill. Perimeter wall The perimeter wall, culverts and drainage units, lighting and other essential physical security areas. The drainage system and culverts can conceal entry and exit points for potential criminals. Culverts should be grilled to make it difficult for Criminals activities to occur. Parking lot Here the security personnel should be in a position to see how vehicles entering the premise or exiting are inspected. In some organizations parking badges are issued while in many more identification from drivers is not produced. In some organizations it is indicated cars parked at owner’s risk which injects confidence to car vandals and absorbs security responsibility. Parking should be offered to personnel with previous security background. The adjacent buildings and windows. The buildings and windows near a facility should not serve as a spring board for criminals to gain entry. The windows should be well and adequately secured to deny criminals an opportunity to access the facility under surveillance. Key Control and Locks Knowing who has which keys to which locks at all times is a vitally important issue. Failure to maintain such control may defeat the entire purpose of creating a security system. Institutions often simply assume that no one leaving their service either an employee or volunteer will subsequently break into their building or office. A sound key-control policy is essential to an effective security program. There should be a central key control location where masters are kept and access to which is strictly controlled. Registry. A central key control registry should be established for all key sand combinations. Employees and leadership should be required to sign for keys when they are received and the return of keys should be an important part of an exit process. Issuance. Supervisory approval should be required for the issuance of all keys and locks. Spare keys and locks should be kept in a centrally located cabinet, locked under the supervision of a designated employee. Master keys should be issued to a very restricted number of employees and these should be inventoried at least twice each year. Re-keying. When key control is lost, it may be worthwhile to have an institution’s locks Re-keyed or key should be surrendered incase employee is terminated or retired. Combination Locks and Codes. Where combination locks and coded locks are used, those combinations and codes should be changed at least every six months or when employees or leadership leave your premise. Combinations should also be kept under strict control of management. Computer systems and access. The computer system has become a concern in computer industry today. The security of electronic gadgets is pivotal in the growth of organizations, sabotage and shrinkage. The system should be protected from intruders or unauthorized access. The surveyor should include know who uses which computer, which services would be jeopardized by failure of a certain computer. Fires Are unpredictable hazards to organizations, homes and industries. The degree of vulnerability varies from one organization to another. The surveyor should check on the existing fire hazards, verify a match between hazards existing and fire suppression devices. Safes The area containing valuables is of paramount importance to a security survey. The protection of valuables should be consistent with security physical measures and criticality of a potential loss occurs. Safes and valuable storage areas should be fitted with adequate alarm systems. Surveillance Surveillance devices, CCTV’s and motion picture cameras are key to criminal activities detection, apprehension and deterrence. The surveyor should know their existence, location, protection and who monitors them. The security survey should capture the various departments in the organization, their operations and internal controls. Protective Lighting The value of adequate lighting as a deterrent to crime cannot be overemphasized. Adequate lighting is a cost-effective line of defense in preventing crime. Some Considerations on Lighting Lighting, both inside and outside, is most helpful and can be installed without becoming overly intrusive to neighbors. All entrances should be well lit. Fences should also be illuminated. For outside lighting, the rule of thumb is to create light equal to that of full daylight. The light should be directed downward away from the building or area to be protected and away from any security personnel you might have patrolling the facility. Where fencing is used, the lighting should be inside and above the fencing to illuminate as much of the fence as possible. Lighting should be placed to reduce contrast between shadows and illuminated areas. It should be uniform on walkways, entrances, exits, and especially in parking areas. Perimeter lights should be installed so the cones of illumination overlap, eliminating areas of total darkness if any one light malfunctions. Fixtures should be vandal-resistant. It is vital that repair of defects and replacement of worn-out bulbs be immediate. In addition, prevent trees or bushes from blocking lighting fixtures. You may wish to use timers and/or automatic photoelectric cells. Such devices provide protection against human error and ensure operation during inclement weather or when the building is unoccupied. A security professional should be contacted to help you with decisions on location and the best type of lighting for your individual institution. REFERENCE James K. Broder (200), Risk Analysis And The Security Survey 2rd Ed. Butterworth-Heinemann. USA. Lawrence J. Fennely (2003), Physical Security 3rd Edition. Elsevier Butterworth-Heinemann. Burlington, UK. Marc Weber Tobias (200), Locks Safes and Security, An International Police Reference 2nd Ed. Illinois USA.

Ionic Radius Trends in the Periodic Table

The ionic radius of the elements exhibits trends in the periodic table. In general: Ionic radius increases as you move from top to bottom on the periodic table.Ionic radius decreases as you move across the periodic table, from left to right. Although ionic radius and atomic radius do not mean exactly the same thing, the trend applies to the atomic radius as well as to the ionic radius. Key Takeaways: Ionic Radius Trend on Periodic Table The ionic radius is half the distance between atomic ions in a crystal lattice. To find the value, ions are treated as if they were hard spheres.The size of an elements ionic radius follows a predictable trend on the periodic table.As you move down a column or group, the ionic radius increases. This is because each row adds a new electron shell.Ionic radius decreases moving from left to right across a row or period. More protons are added, but the outer valence shell remains the same, so the positively charged nucleus draws in the electrons more tightly. But for the nonmetallic elements, the ionic radius increases because there are more electrons than protons.While the atomic radius follows a similar trend, ions may be larger or smaller than neutral atoms. Ionic Radius and Group Why does radius increase with higher atomic numbers in a group? As you move down a group in the periodic table, additional layers of electrons are being added, which naturally causes the ionic radius to increase as you move down the periodic table. Ionic Radius and Period It might seem counterintuitive that the size of an ion would decrease as you add more protons, neutrons, and electrons in a period, yet, theres an explanation for this. As you move across a row of the periodic table, the ionic radius decreases for metals forming cations, as the metals lose their outer electron orbitals. The ionic radius increases for nonmetals as the effective nuclear charge decreases due to the number of electrons exceeding the number of protons. Ionic Radius and Atomic Radius The ionic radius is different from the atomic radius of an element. Positive ions are smaller than their uncharged atoms. Negative ions are larger than their neutral atoms. Sources Pauling, L. The Nature of the Chemical Bond. 3rd ed. Cornell University Press, 1960.Wasastjerna, J. A. On the radii of ions.  Comm. Phys.-Math., Soc. Sci. Fenn.  vol. 1, no. 38, pp. 1–25, 1923.