• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.12
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• pp.50-59
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• 2000

This paper presents a new SRAM testing method for various faults by monitoring dynamic power supply currents. The peak value of Iddt pulses when the transition write operation is performed, is prominently different from that of a fault free case. Using the observation, a new memory test algorithm is developed which consists of only write operations. The new test algorithm using dynamic power supply current testing, has length of 7n, where n is the number of cells in SRAMs. Compared to the previous March B algorithm, the test length has been reduced by 7/17, and can detect additional hard-to-detect faults.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.759-766
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• 2004

Busan has its unique character which differed from inland such as Seoul and Daegu Because Busan is located in coast district of Korea, it could be inferred that the climate change in Busan had been influenced by foreshore reclamation in the urbanization process. The purpose of this study is to investigate the relationship between reclamation of the foreshore and climate change by analysing the climate change over the past 70 years in three metropolitan cities. The conclusion from this study are as follows. 1) There was not a big difference among elements of climate change in three cities. 2) Annual mean minimum temperature in Seoul and Daegu had remarkably increased over the past 70 years. On the other hand, annual maximum temperature in Busan had a sudden rise in the only tome to reclaim the foreshore.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.338-339
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• 2011

본 연구는 해양플랜트 지원선 중 작업자들에게 전용거주시설을 제공하는 생활바지선 거주구공간계획에 관한 연구이다. 생활바지선의 거주구는 '작업자영역', '서비스영역', '승무원영역', '업무영역'으로 공간을 분류할 수 있다. 본 연구에서는 현재 사용되고 있는 10척의 생활바지선 일반배치도(GA)를 조사하여 거주공간특성을 분석하였다. 또한 해양플랜트 거주구 설계시 가장 많이 참조되는 ABS, NORSOK 등 해외선급협회에서 제시하는 해양플랜트 거주구 공간설계지침을 분석하여 생활바지선에서 거주구 공간계획에 적용하기위한 설계지침을 제시하였다. 그리고 생활바지선 거주구 설계모델을 설정하고 모델을 대상으로 데크별 공간배치와 동선을 계획하였다. 마지막으로 거주구 설계모델의 객실, 식당, 주방, 휴게공간 그리고 위생시설 등 주요공간을 대상으로 공간계획을 실시하고 계획안을 제시하였다. 최근 국내 조선업계에서도 생활바지선에 대한 관심이 증가하고 있으나 거주구 공간설계기술의 부족으로 외국 설계업체에 의존하고 있는 형편이다. 따라서 우선 한국선급협회에서 본 연구결과를 기초 생활바지선 거주구 공간계획을 위한 설계지침을 시급히 만들어야만 한다.

• Wind and Structures
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• v.20 no.1
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• pp.75-93
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• 2015

This work is focused on a parametric numerical study of the barrier's bar inclination shelter effect in crosswind scenario. The parametric study combines mesh morphing and design of experiments in automated manner. Radial Basis Functions (RBF) method is used for mesh morphing and Ansys Workbench is used as an automation platform. Wind barrier consists of five bars where each bar angle is parameterized. Design points are defined using the design of experiments (DOE) technique to accurately represent the entire design space. Three-dimensional RANS numerical simulation was utilized with commercial software Ansys Fluent 14.5. In addition to the numerical study, experimental measurement of the aerodynamic forces acting on a vehicle is performed in order to define the critical wind disturbance scenario. The wind barrier optimization method combines morphing, an advanced CFD solver, high performance computing, and process automaters. The goal is to present a parametric aerodynamic simulation methodology for the wind barrier shelter that integrates accuracy and an extended design space in an automated manner. In addition, goal driven optimization is conducted for the most influential parameters for the wind barrier shelter.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.3
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• pp.46-53
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• 2009

To find the working condition is one of the important factors in precision machining. In this study, we analyzed maximum working temperature by infra-red camera and surface roughness in side wall end milling using design of experiment (DOE): RSM(response surface methodology), ANOM(analysis of means) and ANOVA(analysis of variance) by table of orthogonal array. ANOM and ANOVA are well adapted to select sensitivity of design variables for maximum working temperature and surface roughness. The effective design variables and their levels should be determined using ANOM, ANOVA. RSM is presented 2nd order approximation polynomial of maximum working temperature and surface roughness is composed with design variables. Therefore, it is expected that the proposed procedure using design of experiment : table of orthogonal array, ANOM, ANOVA and RSM can be easily utilized to solve the problem of working condition.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.101-108
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• 2017

Recently, the patent rights for 3D printing technology have expired, while 3D printers with RP (Rapid Prototyping or Additive Manufacturing) and 3D printing technologies are receiving attention. In particular, the development of 3D printers is rapid in Korea, thanks to the increasing sales and popularity of FDM (Fused Deposition Modeling or Fused Filament Fabrication) 3D printers. However, the quality and productivity of the FDM 3D Printer are not good, so customers prefer the DLP (Digital Light Processing) method to avoid these shortcomings. The DLP method has high quality and productivity. However, because of the stereolithography equipment, it has few studies compared to optimal values for elements then FDM 3D printing study. In this study, to find the optimal conditions for 3D printing with the DLP method, the aim is to obtain the optimal values (strength, final time, quality) by changing the light exposure time, layer thickness, and z-axis speed.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.639-643
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• 1997

This paper presents how nonlinear PID control algorithms can be applied on chemical processes for a more stable operation and perfect automation. A pass balance controller is designed to balance the exiting temperatures of a heater and a heat exchange network. The proposed controller has gain-varying integral action and deals with the operational constraints in an efficient manner. Also, the use of a PID gap controller is proposed to maximize energy saving and operation stability and to minimize operator intervention in operation of air fan coolers. The proposed controller adjusts the opening of a louver automatically in such a way that it keeps the air fan pitch position within the desired range. All these nonlinear PID controllers have been implemented on the distributed control system (DCS) for good reliability and operability. Operator acceptance was very high and the implemented controllers have shown good performance and high service factor still now on. The proposed methodology can be directly applied to similar processes without any modification.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.17-26
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• 1991

Beta ray $(^{90}Sr+^{90}Y)$ absorbed dose at tissue surface was measured from the distance of 30cm by use of extrapolation chamber. In the measurement, following factors were considered: effective area of collecting electrode, polarity effect, ion recombination and window attenuation. The measured absorbed dose rate at tissue surface was $1.493{\mu}Gy/sec$ with ${\pm}2.9%$.

• Annual Conference on Human and Language Technology
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• 1993.10a
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• pp.527-532
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• 1993

한국어 어휘부 구성에 기능동사(경동사) 구문에 관한 언어정보의 수록은 필수적이다. 범용적 대규모 한국어 어휘자료 database 구축을 위한 기능동사 구문과 언어학적 분석 기술과 관련하여 제기되는 여러 문제들 중에서 기능동사의 어휘적 한정의 문제는, 어휘부 중심의 논의를 펼칠 때, 각별한 중요성을 갖는다. 본 발표에서는 우선 확장된 기능동사 개념에 의거하여 기능동사 정보를 어휘부에 반드시 수록해야 할 논거를 제시하고, 기능동사의 어휘적 한정의 문제를 집중적으로 거론하고자 한다. 요점은 기능동사 구문이 서술명사와 기능동사의 결합에 의해 성립된다고 볼 때 이 두 범주의 어휘적 실현은 예측불가능한 제한적 결합관계에 의해 특징지어지므로, 일정한 서술명사와 결합 가능한 기능동사의 어휘적 형태를 어휘부에서 낱낱이 한정하고 기재하여야 하리라는 것이다. 이를 위한 필수적인 연구작업은 크게 상호보완적인 두 부분으로 이루어진다. 한편 한국어 서술명사의 총체를 목록화하고, 그 개별어휘 하나하나에 대해 가능한 기능동사 구문과, 구체적인 기능동사 어휘를 한정하는 것이 필요하다. 또 한편으로는 한국어 동사의 총체를 목록화하여, 그 개별어휘 하나하나의 가능한 통사적 실현을 체계화하는 과정에서 기능동사 용법을 빠짐없이 가려내는 작업이 요구된다고 보겠다.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.73-80
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• 2003

The purpose of this study was to analyze daylighting performance in a semi-infinite size office space for lighting energy conservation. DOE2.1E was used for simulations for the model space of $12\times12\times2.6m$. Nomographs were developed which could simulate work plane illuminance, glare index, energy consumption rate and energy reduction rate for daylighting design. Major results of simulations are as follows ; 1) When blinds facing south were installed, 43% of workplane illuminance diminished, but the flare index didn't exceed the recommended max-glare value. 2) In a semi-infinite office space facing south. energy consumption rate in the case space of 500 lux workplane illuminance is larger then case space of 300 lux workplane illuminance. Therefore, energy reduction rate is increased when the semi-infinite office faces south and naintains 300 lux workplane illuminance level.