• 한국항공운항학회지
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• 제29권3호
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• pp.44-51
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• 2021

PIP is an abbreviation of 'Performance Improvement Package', which is a package that can improve performance by applying some design changes to existing aircraft. Boeing provides PIP applicable to B777-200, and Airbus provides PIP applicable to A350-900 as standard. PIP provided by Boeing and Airbus is a separate task, but it is expected to reduce fuel consumption by reducing drag through aerodynamic improvements. The PIP applied to the A350-900 includes work such as increasing Winglet Height and re-twisting Outboard Wing. This study is to verify the effect of PIP application of the A350-900 aircraft and use it as basic data for economic analysis. The aerodynamic improvement studies and expected effects of the PIP application were examined, and the actual flight data of the PIP-applied and the non-applied aircraft were compared to confirm the PIP application effect. This paper provides empirical results for the aviation industry on the PIP application efficiency as a method of improving fuel efficiency and reducing carbon emission.

• 한국신뢰성학회지:신뢰성응용연구
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• 제3권2호
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• pp.103-116
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• 2003

We carry out reliability tests and investigate the failure mechanisms. of the wafer level vacuum packaged MEMS gyroscope sensor using an accelerated degradation test. The accelerated degradation test (ADT) is used to evaluate reliability (and/or life) of the MEMS vacuum package and to select the accelerated test conditions, which reduce the reliability testing time. Using the failure distribution model and stress-life model, we are able to estimate the average life time of the vacuum package, which is well agreed with the measured data. After improving several package reliability issues such as prevention of gas diffusion through package, we carry out another set of accelerated tests at the chosen acceleration level. The results show that reliability of the vacuum packaged gyroscope has been greatly improved and can survive without degradation of performance, which is the Q-factor in gyroscope sensor, during environmental stress reliability tests.

• 대한전자공학회논문지TC
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• 제41권8호
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• pp.19-26
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• 2004

패키지는 전기적인 특성에 있어서 우수한 고주파 전송 특성을 지녀야한다. 그러나 집적회로면이 위로 향하는 세라믹 패키지(Face-up Package)는 본드와이어 연결 시 고주파의 기생 특성이 크게 증가하여 시스템 전체의 성능에 큰 제한을 가져온다. 본 논문에서는 향상된 정합특성을 갖는 새로운 밀리미터파 세라믹 패키지 급전구조를 제안하였고, 유한요소법(FEM: Finite Element Method)을 이용하여 20 ∼ 50 GHz에서 해석 및 설계를 하고 제작하였다. 측정 결과, 삽입된 금속판 (Embedded Metal Sheet)을 가지는 세라믹 패키지 급전구조는 47GHz까지 기존의 세라믹 패키지보다 0.85dB 그리고 본드와이어 부분에 일반적인 에폭시( ε/sub γ/ = 4)를 사용하여 몰딩한 세라믹 패키지보다 0.4dB가 개선된 삽입손실의 특성을 얻을 수 있었다. 따라서 본 해석결과는 소형의 세라믹 패키지 및 MMIC(Monolithic Microwave Integrated Circuit) 모듈 개발에 효과적으로 활용될 수 있으리라 기대된다.

• 경영과학
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• 제25권1호
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• pp.55-74
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• 2008

In recent warfare, the performance improvement of air weapon systems enables an aircraft to strike multiple targets on a single sortie. Further, aircrafts attacking targets may carry out an operation as a strike package that is composed of bombers, escort aircrafts, SEAD (Suppression of Enemy Air Defenses) aircrafts and etc. In this paper, we present an aircraft allocation model that allocates multiple targets to a single sortie in the form of a strike package. A mixed integer programming is developed and solved by using a commercially available software. The new model is better than existing ones because not only it allocates aircrafts to multiple targets but also it models the concept of the strike package. We perform a computational experiment to compare the result of the new model with that of existing ones, and perform sensitivity analysis by varying a couple of important parameters.

• 한국정보시스템학회지:정보시스템연구
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• 제15권3호
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• pp.87-106
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• 2006

The customer-focused enterprise is interested in integrating every record of an interaction with a customer. This study is to investigate the structural relationship of data integration customer analysis capability, marketing & sales capability, customer service capability, and CRM performance. 205 survey data were collected from the company which implemented the CRM package. SEM analysis shows that data integration has influence on the CRM performance through the improvement of customer analysis capability, marketing 8t sales capability, and customer service capability. The revised model for further goodness-fitting model shows that data integration has influence on the improvement of customer analysis capability, marketing & sales capability, and customer service capability. but customer analysis capability has indirect influence on CRM performance through the improvement of marketing & sales capability, customer service capability.

• 한국정보전자통신기술학회논문지
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• 제16권1호
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• pp.33-40
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• 2023

슈퍼 컴퓨팅 기술 및 하드웨어 기술의 발달로 수치 연산 방식 또한 고도화되고 있다. 그에 따라 이전 대비 향상된 기상 예측 또한 가능해진다. 본 논문에서는 SCAM(Single-Columns Atmospheric Model, CESM(Community Earth System Model)을 간소화 한 버전)에 포함되어 있으며 대기 연산을 수행하는 적운 모수화 코드, Unicon(A Unified Convection Scheme)의 성능을 향상하기 위하여 소스 코드 내의 선형대수 수치적 연산 부분에 고밀도 선형대수 연산을 위한 라이브러리인 LAPACK(Linear Algebra PACKage) BLAS(Basic Linear Algebra Subprograms)의 level1 함수를 적용할 것을 제안한다. 이를 분석하기 위하여 SCAM의 전체적인 실행 구조도를 제시하고 해당 실행환경에서 테스트를 진행하였다. 기존 소스 코드 대비 SCOPY 함수는 0.4053%, DSCAL 함수는 0.7812%, DDOT 함수는 0.0469%의 성능 향상을 이끌어 내었으며 이를 모두 적용한 결과 기존 소스 코드 대비 0.8537%의 성능 향상을 보였다. 이는 본 논문에서 제안한 고밀도 선형대수 연산을 위한 라이브러리인 LAPACK BLAS 적용 방법이 동일한 CPU 환경에서 추가적인 하드웨어의 개입 없이 성능을 향상시킬 수 있음을 의미한다.

• Steel and Composite Structures
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• 제43권5호
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• pp.533-552
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• 2022

The current article deals with the dynamic stability, and structural improvement of vibrating electrically curved screen on the viscoelastic substrate. By considering optimum value for radius curvature of the electrically curved screen, the structure improvement of the system occurs. For modeling the electrically system, the Maxwell's' equation is developed. Hertz contact model in employed to obtain contact forces between impactor and structure. Moreover, variational methods and nonlinear von Kármán model are used to derive boundary conditions (BCs) and nonlinear governing equations of the vibrating electrically curved screen. Galerkin and Multiple scales solution approach are coupled to solve the nonlinear set of governing equations of the vibrating electrically curved screen. Along with the analytical solution, 3D finite element simulation via ABAQUS package is provided with the aid of a FE package for simulating the current system's response. The results are categorized in 3 different sections. First, effects of geometrical and material parameters on the vibrational performance and stability of the curves panel. Second, physical properties of the impactor are taken in to account and their effect on the absorbed energy and velocity profile of the impactor are presented. Finally, effect of the radius and initial velocity on the mode shapes of the current structure is demonstrated.

• 한국IT서비스학회지
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• 제20권2호
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• pp.57-76
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• 2021

Today's ERP system has become a core system of IT·SW that not only supports and manages enterprise resources efficiently, but also encompasses major business tasks. In other words, the ERP system is an essential strategic element for the survival of a company as a powerful means to innovate the management of an organization. This study analyzed the impact on the utilization of IT·SW from the perspective of the entire organization's process without limiting the performance evaluation of the ERP system itself, which is a core system of a company. The measurement data for evaluating the performance of the ERP system was the 2018 domestic company IT·SW utilization survey result report (subject to survey : 3,017 domestic companies with 10 or more employees). Based on this data, this study analyzed the impact of the ERP system on the entire enterprise's IT·SW utilization. In particular, attention was paid to whether there would be a difference in the use of IT·SW if the type of ERP system introduction was changed through the improvement of the business process of the company. Multiple regression analysis was performed using the statistical package SPSS 25. As a result, among the ERP system introduction types, the greatest degree of (+)influence on the company's IT·SW utilization is when the ERP package SW or ASP service is used as it is. Although the difference is insignificant, the second case was to build an ERP system through self-development or outsourcing, followed by customizing the package SW or system through self-development or outsourcing. Through the results of this study, it is expected that the organization will improve the business process and use the standard ERP package SW as it is without modification, thereby effectively enhancing the use of IT·SW of the company and leading to management performance.

• 제어로봇시스템학회논문지
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• 제13권11호
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• pp.1128-1136
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• 2007

This paper presents an application study of a model predictive control based commercial package PCTP to real chemical processes. The first case study concerns a product purity control of a splitter process which distillates styrene from undesired component ethyl-benzene produced from ethyl-benzene dehydrogenation reaction. The second case study is about a temperature control of ethyl-benzene dehydrogenation reactor and an excess oxygen control of the fired heater. Optimum control structure for MPC application is developed for each case study. The application results show a significant improvement in control performance and stability.

• 한국식품조리과학회지
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• 제29권1호
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• pp.63-71
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• 2013

The purpose of this study was to analyze the gap between importance and performance in perceived sanitation management for general hospital foodservice operations. Data were collected through surveys given to 168 hospital dietitians in the Seoul-Incheon, Gyeonggi-do, Daegu, and North Gyeongsang province. The 65 questionnaires from total questionnaires were usable and the response rate was 38.7%. All statistical analyses were conducted using the SPSS package program (version 20.0) for t-test, ANOVA, and importance-performance analysis (IPA). According to the importance and performance analysis for 26 items, the importance score was significantly higher than the performance score for 22 items. In addition, the results of IPA showed the following areas as improvement priorities: handling foods on working table and management of distribution temperature. In conclusion, the performance level of prerequisite programs applying to the hospital foodservice needs improvement, especially cross-contamination prevention and temperature control for distribution. Additionally dietitians should be educated about sanitation management items that perceived to be less important than the others.