• 한국안전학회지
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• 제23권4호
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• pp.1-6
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• 2008

This experiments are perfol1ned to investigate the effect of ventilation velocity on a high pressure water mist tire suppression in train. The experiment is conducted in half scale modeled train of a steel-welled enclosure (5.0m${\times}$2.4m${\times}$2.2m). The ventilation velocity is controlled by the ventilation duct through an inverter in the range of 0 to 3m/s. The coverage-radius and an injection angle of an high pressure water mist system are measured. The mist nozzle with 5-injection holes is operated with pressure 60bar. The heptane pool fires are used. The fire extinguishment times and the temperature are measured for the ventilation velocities. In conclusion, because the momentum of injected water mist is more dominant than that of ventilation air, the characteristics of water mist, the fire extinguishment times and the temperature are affected very little by ventilation velocity.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.161-168
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• 2020

Over the last half-century, computer science has revolutionarily changed the landscape of humanities research. This digital shift in research methodology has reached from the brainstorming process to preserving, constructing, collecting, visualizing, and even analyzing materials. Such transformation has brought about the birth of the new field of study: Digital Humanities (DH). DH undeniably has saved much of the physical chores and provided a new angle to interpret the text, thereby making its meteoric rise as a promising future of the humanities. Based on such innovation, electronic circuitry can seem to replace the imagination that detects relationships and significances of research data with ever-improving interfaces. However, despite hitherto technological development, the thousands-year-old essence of traditional liberal arts-human creativity-remains the heart of humanities research and always will. This paper starts by proving this proposition in the way of comparing the old and new liberal arts research methods, focusing on literary studies. Meanwhile, it thoroughly investigates how digitalized bibliographies, search engines, databases, and digital projects provide the most useful data preservation and virtual experience of browsing in the library, along with their limitations due to the intrinsic quality of humanities research data. Also, it probes the differences between traditional and digital data analysis in current methods of literary studies, ultimately presenting the ideal direction for humanities development in the era of digital convergence.

• 전산구조공학
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• 제8권1호
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• pp.137-146
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• 1995

본 논문에서는 최근 관심이 증대되고 있는 충격하중에 의해 시간의 흐름에 따라 형성되는 구조물의 응력분포 양상을 유한요소 해석적으로 고찰하기 위하여 동적 응력 해석 프로그램을 개발하였다. 유한요소 해석에 의하면, 종방향 응력파는 충격하중이 작용하는 방향과 동일한 방향으로 진행하며, 응력파 선단의 속도와 모양은 이론해석에 의한 결과와 같음을 알 수 있다. 또한 종파의 진행방향에 45.deg. 방향으로 전단파가 발생하여 진행함을 알 수 있으며, 전단파의 속도는 종파의 1/2이 되고, 종파보다 전단파의 강도가 큼을 알 수 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.972-975
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• 2003

We have performed computer simulation to obtain electro-optic characteristics of reflective hybrid aligned nematic liquid crystal displays driven by fringe field. The results show that the optimal retardation value of the cell is $0.289{\mu}m$, which allows for the cell to have a practical cell gap of larger than $3{\mu}m$ when manufacturing. A reflectance of the dark state is only 0.114% for an incident light 550nm. At this condition, the light efficiency of white state reaches 92.7%. Further, we have studied a new reflective display with polarizer, optical compensation with half plate, LC plus reflector. The display with optimized cell parameters shows low wavelength dispersion and the contrast ratio greater than 5 over exists about $120^{\circ}$ in vertical direction and $160^{\circ}$ in horizontal direction.

• Journal of the Korean Data and Information Science Society
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• 제21권5호
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• pp.901-908
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• 2010

다중회귀모형에서 변수선택법 중에서 전진선택과 후진제거의 과정을 기하학적으로 표현하는 그래픽적 방법을 제안한다. 반지름이 1인 반원의 제1사분면에는 전진선택 과정을, 제2사분면에는 후진제거 과정을 표현한다. 각 단계에서 회귀제곱합을 벡터로 표현하고, 추가제곱합 또는 부분결정계수를 벡터 사이의 각도로 나타내며 벡터의 끝을 연결할 때 통계적으로 유의하면 점선으로 표현하여 부분가설검정의 통계적 분석결과를 인지할 수 있도록 작성한다. 이 방법을 이용하면 전진선택과 후진제거 방법에 의한 최종모형을 비교 분석하고 전체적으로 모형의 적합도를 파악할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2374-2376
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• 2004

In this paper, we describe a DSP-based test apparatus for Control Element Drive Mechanism (CEDM). Using this apparatus, we can catch the mechanical and electrical characteristics of CEDM and obtain the information about the improvement of CEDM and the design of CEDM power controller. The test apparatus for CEDM introduced in this paper can input firing angles directly into gate drive circuits of thyristors so that this method can be used to derive the maximum and minimum values of firing angles within available limits for a 3-phase half-wave rectifier. Angle inputs help us understand each coil's response characteristics. Since this apparatus generates a serial sequence for CEDM insertion and withdrawal operations, we may judge whether CEDM works correctly as expected or not in each phase of a step movement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2631-2633
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• 2004

This paper describes the construction of a half sphere screen driving tilting simulator that can perform six degree-of-freedom( DOF) motions simmulator to a tilting train. The mathematical equations of Tilting Train dynamics are first derived from the 6-DOF bicycle model and incorporated with the bogie. carbody, and suspension subsystems. The equations of motion are then programmed by visual C++ code. To achieve the simulator functions. a motion platform that is constructed by six electric-driven actuators is designed. and its kinetics/inverse kinetics analysis is also conducted. Driver operation signals such as carbady angle, accelerator. and tilting positions are measured to trigger the Tilting dynamics calculation and further actuate the cylinders by the motion platform control program. In addition. a digital PID controller is added to achieve the stable and accurate displacements of the motion platform. The experiments prove that the designed simulator is adequate in performing some special rail mad driving situations discussed in this paper.

• 한국공간구조학회논문집
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• 제6권1호
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• pp.75-82
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• 2006

단층 래티스 돔은 작은 단면의 선 부재 조합으로 전체구조물이 구성되는 특성상 구성부재의 세장비, 부재 반개각 하중조건, 접합부 특성 등에 매우 큰 영향을 받으므로, 비선형 좌굴해석에 의한 좌굴하중을 사용해야 하지만 여러 가지 현실적 제약이나 문제점 등에 의해 이러한 것이 제대로 반영되지 않은 설계가 이루어지고 있다. 이러한 이유로 돔 구조물의 설계 시 부재의 과다 설계, 자유로운 형상 설계의 제약 등의 문제점들이 나타나는 것이 지금의 현실이다. 따라서 이 논문의 목적은 위에서 언급된 문제점을 해결하기 위하여 고유치 해석을 통한 선형 좌굴해석에 기초한 비선형 좌굴하중을 예측하고 이를 이용함으로서 보다 효과적인 설계를 가능케 하는 설계식을 제안하는 데 있다.

• 한국기계가공학회지
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• 제13권2호
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• pp.108-116
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• 2014

Considering the run-out effect and cutting force coefficients, the cutting force profile of half immersion end-milling was analyzed in detail. The effects of three specific cutting-force coefficients and three edge-force coefficients are verified. Through a detailed investigation, it is proved that the radial cutting force coefficients and are the major factors which increase the cutting forces Fx and Fy in end-milling. However, the axial cutting force coefficients have no influence on the force Fx and Fy changes in end-milling. Also, the analyzed end-milling force model shows good consistency with the actual measured force with regard to Fx and Fy. Thus, this model can be used for the prediction of the force history in end-milling with run-out, and it incurs a different force history with different start and exit immersion angles as well as holding effects.

• Earthquakes and Structures
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• 제18권5호
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• pp.581-598
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• 2020

This paper aims to investigate the seismic behavior and influence parameters of the large-scaled thin-walled reinforced concrete (RC) tubular columns in air-cooled supporting structures of thermal power plants (TPPs). Cyclic loading tests and finite element analysis were performed on 1/8-scaled specimens considering the influence of wall diameter ratio, axial compression ratio, longitudinal reinforcement ratio, stirrup reinforcement ratio and adding steel diagonal braces (SDBs). The research results showed that the cracks mainly occurred on the lower half part of RC tubular columns during the cyclic loading test; the specimen with the minimum wall diameter ratio presented the earlier cracking and had the most cracks; the failure mode of RC tubular columns was large bias compression failure; increasing the axial compression ratio could increase the lateral bearing capacity and energy dissipation capacity, but also weaken the ductility and aggravate the lateral stiffness deterioration; increasing the longitudinal reinforcement ratio could efficiently enhance the seismic behavior; increasing the stirrup reinforcement ratio was favorable to the ductility; RC tubular columns with SDBs had a much higher bearing capacity and lateral stiffness than those without SDBs, and with the decrease of the angle between columns and SDBs, both bearing capacity and lateral stiffness increased significantly.