• 대한기계학회논문집B
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• 제32권9호
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• pp.712-719
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• 2008

Light Oil Flow Standard System(LOFSS), as a national oil flow standard system, in Korea Research Institute of Standards and Science(KRISS) was developed for oil flowmeter calibration, and the expanded uncertainty of flow quantity determination was estimated within 0.04 %. In order to improve the reliability of the LOFSS measurement, a proficiency test was carried out in the flow range of 20 and $240\;m^3/h$ (Reynolds number $20,000{\sim}900,000$). A turbine flowmeter was used as a transfer package in round robin test. The water flow standard system of KRISS, the pipe prover of the national calibration and test organization and the master meter calibrator of the turbine flowmeter supplier, which used the different working fluid respectively, were compared with the turbine flowmeter measurement. The maximum difference of measurement was 0.15 % between the LOFSS and the pipe prover. The En numbers of the each system measurement were evaluated at the same Reynolds number. It was found that the En numbers were less than 1 in the comparison, which means the procedures of the uncertainty estimation of the each calibrators were reasonable and reliable.

• 마이크로전자및패키징학회지
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• 제17권4호
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• pp.19-26
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• 2010

포화 수증기압이 고출력 형광체 변환 백색 LED 패키지의 열화현상에 미치는 주요 스트레스 인자임을 확인하였다. 또한 LED 패키지의 가속 수명시험을 통하여 포화 수증기압이 효과적인 가속 스트레스 인자임을 확인하였다. 실험조건은 350 mA 전류를 인가한 것과 인가하지 않은 2가지 조건에 대해 $121^{\circ}C$, 100% R.H. 환경에서 최대 168 시간동안 진행하였다. 실험결과 두 실험 모두 광 출력 감소, 스펙트럼 세기의 감소, 누설전류 및 열 저항이 증가하였다. 고장분석 결과 광 특성의 열화는 봉지재의 변색과 기포에 의해 발생한 것으로 나타났다. LED 패키지의 변색과 흡습에 의해 유발되는 기계적 (hygro-mechanical) 스트레스에 의한 기포 발생은 패키지 열화의 중요한 인자로써, 포화 수증기압이 고출력 LED의 수명시험 시간을 단축하기 위한 스트레스 인자로 적합함을 알 수 있었다.

• 한국군사과학기술학회지
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• 제14권2호
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• pp.213-221
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• 2011

Avionics system tends to be designed to have the integrated architecture, and it is getting difficult and complex to verify the flight-critical function because of sophisticated structure. In Korean Utility Helicopter, mission computer acts as the MUX Bus Controller to handle the data from both communication, identification, mission/display and survivability equipment inside Mission Equipment Package and aircraft subsystems such as fuel system and electrical system while it is interfacing with Automatic Flight Control System and Full-Authority Digital Engine Control via ARINC-429 bus. The Flight Displays which is classified as flight-critical function in aircraft is implemented on Primary Flight Display after mission computer processes data from AFCS in order to generate graphics. This paper defines the flight-critical function implemented in mission computer for KUH, and presents the static and dynamic test procedures which is performed on System Integration Laboratory along with Playback Recorder prior to flight test.

• 산업기술연구
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• 제22권B호
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• pp.51-60
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• 2002

Currently, many companies are trying to be more competitive by implementing the most appropriate software package called ERP (Enterprise Resource Planning). ERP can support the company's business process. A manufacturing execution system (MES) is an industrial software system, as well as a manufacturing management function in make-to-order and make-to-stock manufacturing environments. This paper presents an architecture of MES. This study develops MES to identify the functional requirements of loading & scheduling in the automobile industry. This study shows the effectiveness of the proposed MES, how to develop MES and interface with ERP package.

• 한국기계가공학회지
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• 제19권2호
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• pp.63-68
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• 2020

In this study, we analyzed a cold draw (CD) bar packaging automation facility to examine its structural safety. The structural analysis focused on the frame part of the automatic packing machine for the CD round rod widely used in the industrial field, as well as the package supply device, banding suit, and crane part. As a result, we concluded that the structural safety for the banding suit, crane, and package supply device have been secured (safety factors of 9.8, 7.5, and 14.5, respectively). In addition, the safety factor of the transfer was 4.0.

• 항공우주시스템공학회지
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• 제5권1호
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• pp.36-40
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• 2011

In this report US and Korea civil and military simulator certification system is researched, and a plan for improvement is proposed. Korean simulator certification system should adopt FAA's system and improve upon it. Certification criteria should have a basis on FAA certification criteria and add military operation characteristics selectively. Flight test data, used as comparison criteria in certification, should be acquired in package during aircraft development or overseas acquisition. The establishment of certification system is expected to improve external credibility and improve competitiveness in overseas market.

• 정보학연구
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• 제6권3호
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• pp.65-73
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• 2003

본 논문에서는 IBM의 고성능 임베디드(embedded) 프로세서인 405GP와 Linux 2.4.21를 이용하여 5.2GHz 대역에서 최대 54Mbps의 대역폭을 제공할 수 있는 IEEE 802.11a 기반의 AP (Access point) 개발에 관하여 연구하였다. AP의 하드웨어는 PowerPC기반의 IBM 405GP 프로세서를 기반으로 설계하였고 AP 소프트웨어는 405GP을 위한 PowerPC 부트로더, open source인 최근 Linux 커널 2.4.21을 사용하여 구현하였다. 또한 시스템 패키징은 최신 Linux 커널이 지원하는 MTD 기술과 JFFS2 플래쉬 파일시스템을 이용하여 최적으로 구현하였다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.53-58
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• 2003

The Wafer Level Packaging is one of the most important technologies in the semiconductor industry today. Its primary advantages are its small form factor and low cost potential for manufacturing including test procedure. The CASIO's WLP samples, application example and the structure are shown in Fig.1, 2&3. There are dielectric layer , under bump metal, re-distribution layer, copper post , encapsulation material and terminal solder .The key technologies are 'Electroplating thick copper process' and 'Unique wafer encapsulation process'. These are very effective in getting electrical and mechanical advantages of package. (Fig. 4). CASIO and CMK are developing a new System Packaging technology called the Embedded Wafer Level Package (EWLP) together. The active components (semiconductor chip) in the WLP structure are embedded into the Printed Wiring Board during their manufacturing process. This new technical approach has many advantages that can respond to requirements for future mobile products. The unique feature of this EWLP technology is that it doesn't contain any solder interconnection inside. In addition to improved electrical performance, EWLP can enable the improvement of module reliability. (Fig.5) The CASIO's WLP Technology will become the effective solution of 'KGD problem in System Packaging'. (Fig. 6) The EWLP sample shown in Fig.7 including three chips in the WLP form has almost same structure wi_th SoC's. Also, this module technology are suitable for RF and Analog system applications. (Fig. 8)

• 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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2444-2448
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• 2007

The multi channel of DDI which is the core part of the LCD-TV has been propelled. When multi channel in DDI is introduced, it brings a thermal problem because of the increased power. To solve the thermal problem of the DDI it needs to be investigated each at the package level and module level. It is important to extract the junction temperature(Tj) of DDI clearly from the system level. The objective of this research is to construct a compact model. The compact model is to reduce LCD module including DDI. When the compact model is used, it will be able to easily handle the boundary condition and accurately predict the temperature. Consequently, the temperature of DDI can be calculated easily at the system level. Through this research,we also proposed the cooling plan of DDI for a protection of overheating. The cooling plan was utilized in DDI design.