• IE interfaces
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• v.18 no.3
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• pp.317-326
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• 2005

Staff scheduling is an important area, both from an academic and industrial point of view. It has become increasingly important as business becomes more service oriented and cost conscious in a global environment. There has been a lot of study to develop new and efficient staff scheduling models and methods. The purpose of this paper is not to develop new theoretical results but to develop a comprehensive user-friendly staffing model that can be applied to the real-world practice. The developed staffing software, OptStaff, provides the optimal configuration of the customer support center including the selection of customer support center locations, the allocation of staffs to each selected location, and schedules of staffs, so as to minimize the total cost while maximizing the customer satisfaction level. OptStaff also has capability to do scenario analysis by varying the levels of parameters and to create a variety of graphs and reports with user-friendly interfaces.

• Korean Journal of Computational Design and Engineering
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• v.4 no.4
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• pp.318-326
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• 1999

Recently, electronic systems including computers have been rapidly shrinking in size while at the same time the complexity and the capability of these systems continue to grow/sup [1]/. Thus, system volumes have decreased as system power has increased, resulting in dramatic increases in system heat density. The high temperature of the computer system is considered as the major reason for low performance and shortening life of the product. It is necessary to solve this problem due to the heat density increased and to develop the design skill of the computer cabinet according to miniaturization. M4500 desk-top computer was selected for analyzing the thermal management inside cabinet. The cabinet volume, the configuration of the heating devices, the size and location of air ventilation, and the fan selection have been investigated as the important parameters to find out an optimal cabinet design. The objectives of this project were to analyze which design parameters would affect cooling performance by thermal strategy, to design an optimal model, and to measure the temperatures of the main parts to confirm the effect of the thermal design. The temperatures of each part of the optimal model were compared with those of the existing model. As a result. the volume of this miniaturized model was about 16% smaller than that of M4500 without any change in operating performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.74-83
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• 2018

It is very crucial activities that Korean army have to detect and recognize enemy's locations and types of weapon of their artillery firstly for effective operation of friendly force's artillery weapons during wartime. For these activities, one of the most critical artillery weapon systems is the anti-artillery radar (hereafter; radars) for immediate counter-fire operations against the target. So, in early wartime these radar's roles are very important for minimizing friendly force's damage because arbiters have to recognize a several enemy's artillery positions quickly and then to take an action right away. Up to date, Republic of Korea Army for tactical artillery operations only depends on individual commander's intuition and capability. Therefore, we propose these radars allocation model based on integer programming that combines ArcGIS (Geographic Information System) analysis data and each radar's performances which include allowable specific ranges of altitude, azimuth (FOV; field of view) and distances for target detection, and weapons types i.e., rocket, mortars and cannon ammo etc. And we demonstrate the effectiveness of their allocation's solution of available various types of radar asset through several experimental scenarios. The proposed model can be ensured the optimal detection coverage, the enhancement of artillery radar's operations and assisting a quick decision for commander finally.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.3
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• pp.109-117
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• 2013

This study designed a "Diagnostic Model for Management Innovation of Medium Enterprises" based on the theoretical background of success factor and management diagnosis model for management innovation of medium enterprises and suggested a measure for utilization of strategic subject and diagnostic model that enterprises can apply. Utilization of medium enterprises management innovation diagnostic model designed through this study would be of help for making a diagnosis of the capability maturity level of enterprises' current management system and improving it by establishing a challenging capability objective and building a circulation system capable of innovating enterprises. It is expected for enterprises to overcome growing pains and establish a management system capable of achieving outcome (productivity) by repeating measurement and innovation through management diagnosis. In addition, this study provides a method to produce a strategic subject, select priority of implementation and prepare an implementation road map by classifying and filtering management issues produced as a result of management diagnosis in a systematic way. If variables necessary for production of an objective weighted value of scoring and discover of elements for category of diagnostic model and elementary items as well as design of a self-diagnosis questionnaire, measurement of management outcome suggested in this study can be able to be verified and supplemented through case study in the future, it is expected to make the degree of completion as a diagnostic model elevated that may help for growth and development through innovation of medium enterprises.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.178-198
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• 2002

1980년대 초기 미 국방성에서는 소프트웨어 개발업체의 소프트웨어 개발능력에 대한 판단 착오로 금전적, 시간적, 성능상의 많은 어려움을 겪어왔다. 따라서 미 국방성은 카네기 멜론 대학의 SEI(Software Engineering Institute)를 통하여 소프트웨어 개발능력을 측정하고, 조직의 소프트웨어 프로세스 성숙수준을 결정하기 위한 CMM(Capability Maturity Model)을 개발하였다. 그러나 CMM에 기반을 둔 소프트웨어 프로세스 평가 방법은 외부 전문가를 이용하여 평가하므로, 시간과 비용이 많이 소모되는 방법이다. 따라서 많은 기업에서 이러한 평가를 수행하는데 어려움을 느끼고 있다. 특히, 중ㆍ소규모의 조직에서 사용하기에는, CMM의 평가방법은 너무 복잡하고 추상적이다. 소규모 기업의 경우에 3년여에 걸친 프로세스 향상노력으로 많은 성과가 이루어 졌음에도 불구하고 CMM의 평가방법을 이용한 결과는 1 단계 수준을 벗어나지 못하였다는 사례들이 많이 발표되고 있다 이러한 결과들은 CMM의 평가 방법은 중소 규모 조직에는 적절치 않다는 것을 입증한다. 따라서 중소 규모 기업이나 조직의 소프트웨어 프로세스의 성숙도 평가와 개선을 위한 모델들을 개발하기 위한 노력이 전 세계적으로 광범위하게 펼쳐지고 있다. 본 연구에서는 최근의 모델인 CMMI(Capability Maturity Model Integration)의 소프트웨어 프로세스 영역 분류에 의거해서, 우리나라의 소프트41어의 개발과 취득에 관련된 조직들이 각 프로세스 영역을 얼마나 중요하게 평가하는지, 그리고 해당 영역에서의 기준, 절차 그리고 방법을 문서화시키는 것을 얼마나 중요하게 평가하는지를 조사하였다. 한국의 소프트웨어 개발 관행은 CMM이나 ISO 15504 등에서 바람직한 것으로 제시하고 있는 국제 표준과는 많이 다르며, 나아가서는, 예를 들어, 미국의 일반적인 관행과도 많이 다를 수 있다. 따라서 미국이나 유럽의 대규모 소프트웨어 조직을 위해서 개발된 CMM이나 ISO 15504 등은 우리나라의 중소 규모 소프트웨어 조직에는 특히 부적절할 수 있다 본 연구에서는 우리나라 소프트웨어 조직의 종류, 조직의 규모, 그리고 프로젝트 수행 규모에 따라서 각 소프트웨어 프로세스 영역의 중요도가 어떻게 다른지, 그리고 해당 소프트웨어 프로세스 영역의 기준, 절차 그리고 방법을 문서화시킬 필요성이 어떻게 변하는가를 조사하였다. 본 연구 결과는 우리나라의 소프트웨어 조직들이 프로세스 개선을 위해서 무엇을 정말로 필요로 하는지를 밝힘으로써, 한국 소프트웨어 산업의 현실적인 특수성을 고려한 소프트웨어 프로세스 평가와 개선 모델의 개발을 위한 기초적인 자료를 제공할 것으로 예상된다. 또한, 본 연구 결과는, 우리나라 소프트웨어 조직들이 실제로 무엇을 필요로 하는지를 밝힘으로써, 우리나라의 소프트웨어 산업을 육성하기 위한 실효성 있는 정책 입안을 위한 기초 자료를 제공할 것으로 예상된다.

• Smart Structures and Systems
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• v.13 no.1
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• pp.137-154
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• 2014

Servohydraulic shaking tables are being increasingly used in the field of earthquake engineering. They play a critical role in the advancement of the research state and remain one of the valuable tools for seismic testing. Recently, the National Earthquake Engineering Research Center, CGS, has acquired a 6.1m x 6.1 m shaking table system which has a six degree-of-freedom testing capability. The maximum specimen mass that can be tested on the shaking table is 60 t. This facility is designed specially for testing a complete civil engineering structures, substructures and structural elements up to collapse or ultimate limit states. It can also be used for qualification testing of industrial equipments. The current paper presents the main findings of the experimental shake-down characterization testing of the CGS shaking table. The test program carried out in this study included random white noise and harmonic tests. These tests were performed along each of the six degrees of freedom, three translations and three rotations. This investigation provides fundamental parameters that are required and essential while elaborating a realistic model of the CGS shaking table. Also presented in this paper, is the numerical model of the shaking table that was established and validated.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.1
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• pp.20-27
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• 2001

Aerodynamic sensitivity analysis is performed for the Navier-Stokes equations coupled with two-equation turbulence models using a discrete adjoint method and a direct differentiation method respectively. Like the mean flow equations, the turbulence model equations are also hand-differentiated to accurately calculate the sensitivity derivatives of flow quantities with respect to design variables in turbulent viscous flows. The sensitivity codes are then compared with the flow solver in terms of solution accuracy, computing time and computer memory requirements. The sensitivity derivatives obtained from the sensitivity codes with different turbulence models are compared with each other. The capability of the present sensitivity codes to treat complex geometry is successfully demonstrated by analyzing the flows over multi-element airfoils on Chimera overlaid grid systems.

• Smart Structures and Systems
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• v.25 no.1
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• pp.47-56
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• 2020

This paper proposes a model-based approach for structural damage identification and quantification. Using pseudo modal strain energy and mode shape vectors, a damage-sensitive objective function is introduced which is suitable for damage estimation and quantification in shear frames. Whale optimization algorithm (WOA) is used to solve the problem and report the optimal solution as damage detection results. To illustrate the capability of the proposed method, a numerical example of a shear frame under different damage patterns is studied in both ideal and noisy cases. Furthermore, the performance of the WOA is compared with particle swarm optimization algorithm, as one the widely-used optimization techniques. The applicability of the method is also experimentally investigated by studying a six-story shear frame tested on a shake table. Based on the obtained results, the proposed method is able to assess the health of the shear building structures with high level of accuracy.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.3
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• pp.71-78
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• 2011

This parer proposes application of quality costing system in quality improvement area. Cost of quality in quality improvement area provides a valuable of both providing the need for improvement and giving a starting point for project. WQCMS(Web-based Q-Cost Management System) have ability to collect and analyze quality data generated from various different departments in the inside or outside of the enterprise without any limitations, if end-users are able to access wide area network. It provides the capability to integrate quality information from database and to generate various easy analysis reports to management's needs using built-in analysis tool modules with real-time. Web-based quality cost management system to measure the performance of quality improvement activities in the business firms. This paper proposes standard model for quality cost process in quality improvement area.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.3
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• pp.256-266
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• 2012

Cavitating flow simulation is of practical importance for many engineering systems, such as marine propellers, pump impellers, nozzles, torpedoes, etc. The present work has developed the base code to solve the cavitating flows past the axisymmetric bodies with several forebody shapes. The governing equation is the Navier-Stokes equation based on homogeneous mixture model. The momentum is in the mixture phase while the continuity equation is solved in liquid and vapor phase, separately. The solver employs an implicit preconditioning algorithm in curvilinear coordinates. The computations have been carried out for the cylinders with hemispherical, 1-caliber, and 0-caliber forebody and, then, compared with experiments and other numerical results. Fairly good agreements with experiments and numerical results have been achieved. It has been concluded that the present numerical code has successfully accounted for the cavitating flows past axisymmetric bodies. The present code has also shown the capability to simulate ventilated cavitation.