• 시큐리티연구
• /
• 제7호
• /
• pp.155-189
• /
• 2004

The mission of the police as described by law is to guard the life, body and property of all citizens. Such duties should be accurately performed based on legal and democratic procedures because the works of the police are directively influencing the overall lives of the citizens by restricting their freedom. We are frequently watching the traffic police on the street or road. Traffic policing aims to reduce crime and the opportunities for criminal activity in relation to the use of roads, that is to improve road user behavior in order to reduce accidents. The characteristics of traffic accident change is not similar in each traffic condition. The purpose of this study is to analysis a type characteristics of traffic accident change, such as number of deaths and wounded persons by the time, the vehicle, the type the road, the age group. Based on the characteristics of traffic accident change, traffic accident countermeasures are proposed, in which some variable of traffic policies such as traffic facilities, traffic regulation, and traffic safety education.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.1943-1950
• /
• 2009

The development of high voltage Insulated Gate Bipolar Transistor (IGBT) have given new device advantage in the areas where they compete with conventional GTO (Gate Turnoff Thyristor) technology. The IGBT combines the advantages of a power MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) and a bipolar power transistor. The change of electrical characteristics for IGBT is mainly coming from the change of characteristics of MOSFET at the input gate and the PNP transistors at the output. The gate oxide structure gives the main influence on the changes in the electrical characteristics affected by environments such as radiation and temperature, etc.. The change of threshold voltage, which is one of the important design parameters, is brought by charge trapping at the gate oxide. In this paper, the electrical characteristics are simulated by SPICE simulation, and the parameters are found to design optimized circuits.

• Tribology and Lubricants
• /
• 제11권2호
• /
• pp.44-55
• /
• 1995

Frictional characteristics with the change of dynamic parameters, such as stiffness, inertia and damping, in the friction measurement at dry sliding surfaces were experimentally and theoretically investigated throughout the study. Dynamic frictional force and the variation in the normal load were mainly measured at the various conditions of system dynamic parameters with which stiffness in the normal direction, loading mechanisms and test materials were varied. For the normal load, mechanisms using both a dead weight and a pneumatic cylinder were applied, which resulted in change of the inertia and damping of the test rig. Test materials were steel, rosin and PTFE, which have different types of intrinsic frictional characteristics. Test results showed that frictional characteristics under different dynamic parameters could be different even though the operating variables were the same and also they could result in the variation in the normal load, which could consequently affect the wear mechanism.

• 대한토목학회논문집
• /
• 제39권1호
• /
• pp.33-44
• /
• 2019

최근 기후변화 현실화로 강우 발생 시기와 패턴이 변화하면서 유역에 따라 유황이 변화하고 있는 실정이다. 이로 인한 하천 유황의 장기적 변화는 수중생태계의 구조와 기능에 커다란 변화를 야기한다. 하지만 국내에서는 기후변화와의 연계성은 물론, 유량변화와 생태학적 특성을 포함한 수생태계 관점에서의 분석은 대부분 이루어지지 않고 있다. 따라서 본 연구에서는 기후변화로 인한 현재-미래의 유황 변화가 만경강 하도와 홍수터 영역에서 감돌고기의 서식환경에 미치는 영향을 정량적으로 평가하였다. 그 결과, 현재보다 미래에 홍수와 가뭄 등 극한 수문 조건이 심화됨을 확인하였고, 특히 크기, 빈도, 지속시간, 시기와 변화율 등을 비교 분석함으로써 유황 특성의 변화를 명확히 파악하였다. 그리고 유황 특성과 물리서식처 해석을 연계함으로써 기후변화로 인해 미래 생태환경 변동에 대한 위험성이 크게 증대될 것이라는 결과 제시가 가능하였다.

• 복식문화연구
• /
• 제12권3호
• /
• pp.468-484
• /
• 2004

The purposes of this study were (1) to segment female college students' apparel shoppers into unique apparel buying decision-making style groups; and (2) to profile for each segment in terms of personal characteristics (material values, change seeking tendency and prestige sensitivity) and fashion information sources. Data were collected through questionnaires from convenient sample of 290 female college students. As a result of cluster analysis and univariate analysis of variance, distinctive consumer decision-making style groups of consumers were identified; Value-maximizing Recreational Shoppers, Brand-Maximizing Emotional Shoppers, and Apathetic Shoppers. These three groups were compared as to the effect of personal characteristics variables and fashion information sources through univariate analysis of variance and chi-square statistics. The result showed that personal characteristics (material values, change seeking tendency and prestige sensitivity) and fashion-information sources do influence the consumer decision-making styles and that these three groups were unique in their decision-making characteristics showing that consumer decision-making styles can be a good segmentation base for apparel market.

• Transactions on Electrical and Electronic Materials
• /
• 제9권6호
• /
• pp.223-226
• /
• 2008

$Ge_1Se_1Te_2$ chalcogenide amorphous materials was prepared by the conventional melt-quenching method. Samples were processed bye-beam evaporator systems and RF-sputtering systems. Phase change characteristics were analyzed by measuring glassification temperature, crystallization temperature and density of bulk material. The thermal characteristics were measured at the temperature between 300 K and 700 K, and the electrical characteristics were studied within the range from 0 V to 3 V. The obtained results agree with the electrothermal model for Phase-Change Random Access Memory.

• 유공압시스템학회논문집
• /
• 제1권2호
• /
• pp.20-25
• /
• 2004

In this study, a position control characteristics of pneumatic cylinder with transmission line is analyzed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing stiles of the fluid the diameter and the length of the line. But, the effect of the change of dynamic characteristics of transmission line by the flowing states on the position control characteristics can be neglected because of the friction force of the pneumatic cylinder. So, We assume that the position control characteristics is affected by the diameter and length of the transmission line. The experimental results according to the change of parameter of the transmission line show that the relation between the parameter of the transmission line and the position control characteristics of pneumatic cylinder driving system with the transmission line.

• Architectural research
• /
• 제19권2호
• /
• pp.35-43
• /
• 2017

In South Korea, problems such as low fertility, aging population, and income polarization have recently become more serious. In this time of social change, it is necessary to examine the current changes occurring to residences in order to improve the stability and health of residential areas. The purpose of this study is to investigate the changes of residential areas that occurred between 2000 and 2010 based on detached houses, which are the foundation of residential areas in Seoul. Changes in residential areas can be observed by examining changes in the type of housing and the characteristics of the residents. Since the type of housing and the characteristics of the residents change in the same area, it is necessary to study them together, not as individual elements. Census data is suitable for this purpose, because it can show the changes that have occurred to the housing type and the residents' characteristics within the neighborhood unit. Among the census output areas identified as residential areas based on detached houses, six sites were selected as the case study area based on the rate of change of detached houses. From the result of the case study using the census data, the study area was categorized into three regional types: (i) an urban development and redevelopment area; (ii) an area with a concentration or increasing number of detached houses; (iii) an area with an increasing number of multi-family houses based on detached houses.

• 한국정밀공학회지
• /
• 제17권2호
• /
• pp.80-88
• /
• 2000

This paper presents a method to optimize the bump steer characteristics (the change of toe angle with vertical wheel travel) with respect to hard points in the double wishbone front suspension of the four-wheel-drive vehicle using the design of experiment, multibody dynamics simulation, and optimum design program. Front and rear suspensions are modeled as the interconnection of rigid bodies by kinematic joints and force elements using DADS. The design variables with respect to the kinematic characteristics are obtained through the experimental design sensitivity analysis. An object function is defined as the area of absolute differences between the desired and experimental toe angle. By the design of experiment and regression analysis, the regression model function of bump steer characteristics is extracted. The design variables that make the toe angle optimized are selected using the optimum design program DOT. The lane change simulations and tests of the full vehicle models are implemented to evaluate the improvement of vehicle handling performances by the optimization of front bump steer characteristics. The results of the lane change simulations show that the vehicle with optimized bump steer has the weaker understeer tendency than the vehicle with initial bump steer.

• 국토계획
• /
• 제54권2호
• /
• pp.5-16
• /
• 2019

The purpose of this study is to analyze the spatial characteristics of business-type-changed parcel in the Hongik-University commercial area, from the view point of commercial gentrification. A commercial gentrification occurs through a business-type-change in a spatial basic unit (microscopic spatial unit such as parcel) of an area which has not been considered in relavent policies and research. So, this study analyzed the spatial characteristics of business-type-changed parcels using the Cox's proportional hazard regression model. The main results of this study are as follows. First, as new developments in the adjacent area occur, the business-type-change probability increases. Second, by the commercial area division, the business-type-change probability is different. Finally, the accessibility is better, the probability is higher. These results could suggest that a consideration of the spatial characteristics form microscopic viewpoint is necessary to understand the commercial gentrification. And these could be used as basic data for a gentrification diagnostic and management system, which can predict gentrification from the view point of business-type-change on the basis of a parcel.