• 대한토목학회논문집
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• 제14권1호
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• pp.195-202
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• 1994

본 연구에서는 모래의 전단파괴 포락선의 곡률특성을 구명하고 전단강도와 Been과 Jefferies가 제시한 상태정수간의 매개변수관계를 밝히기 위하여 많은 압밀배수삼축시험의 결과를 분석하였다. 통상적인 삼축시험에서 시료의 단면적 변화와 멤브레인의 영향에 대한 수정은 특히 한계상태를 결정하는데 중요하다고 할 수 있다. 실험결과로부터 전단강도를 밀도와 응력수준의 함수로 표현하는 모델을 제시하였고 모래의 전단파괴포락선의 곡률특성과 상태정수와 전단강도정수간의 관계를 밝혔다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 추계학술발표강연 및 논문개요집
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• pp.17-17
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• 1992

The ceramic high transition temperature superconducting materials present many interesting characteristics that will be analysed from two points of view: physical behavior, and chemical aspects. From the first point of view, these materials display an enormous variety of different physical properties. At low doping levels the normal state shows antiferromagnetism and insulating behavior. At intermediate doping levels, an anomalous metallic state appears and, the optimum Tc in the superconducting state is generated. With increasing doping a normal metallic state develops and superconductivity starts to disappear. Many of the physical phenomena that describe the overall behavior when doping levels are changed will be discussed. From the poing of view of the chemical aspects. we well discuss some of the problems involved in the methods of preparation with particular emphasis on defects, crystal structures, critical currrents, and applications in technology.

• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.33-37
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• 2008

A phenomenological theory of viscosity previously proposed by the present authors8 is applied to the corresponding state theory for the viscosity of liquid. Through the process of the formulation of the corresponding state equation, we can find the simple viscosity equation with no parameters in a reduced form. The liquid viscosities of various substances can be calculated using this equation when we know only the values of the molecular weight and critical constant of substances. A corresponding state equation for the viscosity of liquid from this theory may be applicable to predicting viscosities of various substances under varying temperature and pressure. As a result, this equation may be widely applied to chemical engineering.

• Journal of the Korean Wood Science and Technology
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• 제33권2호통권130호
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• pp.24-28
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• 2005

Monte Carlo simulation was performed on theoretical models of plywood warp for southern yellow pine plywood originating from the United States. The objective of the investigation was to determine which plywood layers was more warp sensitive to veneers that were manufactured to an undesired thickness. This study found that for a balanced panel (a panel of equal target thickness for each of five layers) manufactured veneers of undesired thickness would experience minimal warp. The veneers of undesired thickness placed in the center of the plywood panel also provided a minimum change of plywood warp properties. The panel warp was very sensitive to surface veneers constructed with undesired thickness. Conversely, this study confirms that monitoring of veneer thickness and proper allocations within the plywood lay-up were critical.

• Journal of Microbiology
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• 제34권1호
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• pp.54-60
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• 1996

Taking advantage of the heat inducible HSP82 gene in yeast, chromatin structure after transcription cessation was investigated. Alteration of chromating conformation within the HSP82 gene transcription unit into an active state has been shown to correlate with its transcriptional induction. It was thus of interest to examine whether the active chromatin state within the HSP82 mRNA analysis, the gene ceased its transcription within a few hours of cultivation at a normal condition after heat induction. In this condition, an active chromatin conformation in the HSP82 gene body was changed into an inactie state which was revealed by DNase I resistance and by typical nucleosomal cutting periodicity in the corresponding chromatin. These results thus ruled out the possibility of a long-term maintenance of the DNase I sensitive chromatin after transcription cessation. DNA replication may be a critical event for the chromatin reprogramming.

• 음성과학
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• 제5권1호
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• pp.89-103
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• 1999

It is relatively easy to develop a prototype of a Korean language processing system, but it is very difficult to make it an operational system. In this paper, we survey the current status and methodological issues of the Korean language processing systems such as morphological analyzer, parser and machine translator. In most cases, Korean language processing system easily comes to a dead-end state where its performance can not be improved any more. The reason is that it adopts a general algorithm covering similar problems as a whole because specific low-level problems are not clearly defined and their algorithms are unclear. So, when we add some restrictions to solve an individual linguistic problem, they are also applied to other linguistic phenomena as a side effect. It causes a critical problem that the improvement of the algorithm is very difficult. This paper proposes a 2-step paradigm, a divide-and-conquer method by the functional modularization, a simplification method, and an exception handling technique to develop an operational system that does not fall into a dead-end state.

• Journal of Information Display
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• 제4권1호
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• pp.1-8
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• 2003

Recent progress in both low pretilt and high pretilt defect free C1 surface stabilized ferroelectric liquid crystal (SSFLC) devices is reviewed. First, by numerical calculation to investigate the balance between surface azimuthal anchoring energy and bulk elastic energy within the confined chevron layer geometry of C1 and C2, it is possible to achieve a zigzag free C1 state by low azimuthal anchoring alignment with a low pretilt angle. The critical azimuthal anchoring coefficient for defect free C1 state is calculated. Its relationship with elastic constant, chevron angle as well as surface topography effect are also discussed. Second, using $5^{\circ}$ oblique SiO deposition alignment method a defect free, large memory angle, high contrast ratio and bistable C1 SSFLC display, which has potential for electronic paper applications has also been developed. The electrooptical properties and bistability of this device have been investigated. Various aspects of defect control are also discussed.

• 전기학회논문지
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• 제62권1호
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• pp.95-100
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• 2013

This paper presents a new state feedback control approach for communication networks based control systems in which control input and output observation time-delay natures are generally occurred in practice. We first establish a generic state feedback control framework based on well-known linear system theory. A maximum time-delay value which allows critical stability of whole control system are defined to make a positive definite Lyapunov function which is mathematically composed of controlled system states. We analytically derive its control parameters by using a steepest descent optimization method in order to guarantee a stability condition through Lyapunov theory. Computer simulation is numerically carried out for demonstrating reliability of the proposed NCS algorithm and a comparative study is accomplished to prove its superiority for which the traditional control approach for NCS is made use of under same simulation scenarios.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.45-46
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• 2006

In recent years, micro powder injection molding $(\mu-PIM)$ is being explored as an economical fabrication method for microcomponents in microsystems technology (MST). Technical and economic comparison was performed for $\mu-PIM$ processes. Molding experiment and simulation during the filling process were performed to evaluate several different geometries and processing conditions. The influence of material parameters and process conditions on mold filling were examined as a function of features size using microchannels as an example. It was found that the heat conductivity and viscosity of feedstock, geometry and mold temperature were the most critical parameters for complete filling of micro features.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.842-850
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• 2021

Real Time Simulation (RTS) has long been used in the nuclear power industry for operator training and engineering purposes. And, Online Simulation (OLS) is based on RTS and with connection to the plant information system to acquire the measurement data in real time for calibrating the simulation models and following plant operation, for the purposes of analyzing plant events and providing indicative signs of malfunctioning. An OLS system has been developed to support PWR operations for CPR1000 plants. The OLS system provides graphical user interface (GUI) for operators to monitor critical plant operations for preventing faulty operation or analyzing plant events. Functionalities of the OLS system are depicted through the maneuvering of the GUI for various OLS functional modules in the system.