• Composites Research
• /
• v.26 no.4
• /
• pp.245-253
• /
• 2013

In this paper, we developed a theoretical model which is able to predict the tensile strength and elastic modulus of hybrid composites reinforced by two types of randomly distributed discontinuous reinforcements. For this, we considered two known models; One is a prediction model based on the assumption that the composite is reinforced by two types of well aligned continuous reinforcements. The other is a statistical model for the composite which is reinforced by only one type of randomly distributed discontinuous reinforcements. In order to evaluate the validity of accuracy of our prediction model, we measured the strength and elastic modulus of polypropylene hybrid composite reinforced by talc and short glass fiber. We found that the present model drastically enhances the accuracy of strength prediction compared to an existing model, and predicts the elastic modulus within the same order with experimentally measured values.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.4
• /
• pp.2285-2294
• /
• 2014

Stoltz's AQP is a tool to estimate the level of adversity. The purpose of study is to test the reliability and validity of AQP. The participants were 297 nurses of tertiary hospital in Korea. Data were collected from Aug. to Oct. 2013. Resilience Scale was used as criterion of AQP. Cronbach's alpha test, item total correlation, exploratory factor, correlation analysis, and ANOVA test were used. In result, factor analysis was accounted for four factors explaining 56.256% of total variance and corresponding factors were factor 1 (Control, 10.7%), factor 2 (Ownership, 13.7%), factor 3(Reach, 17.4%), factor 4 (Endurance, 14.9%). The internal consistency was acceptable (Cronbach's alpha=.84). Four factors were positively correlated with RS. AQP is a reliable and valid instrument to measure for adversity quotient in Korean nurse.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.4
• /
• pp.973-983
• /
• 2016

It's been almost 6 years since PIA was implemented based on legislation. So I analyzed problems of PIA from the perspective of ITSM 3 elements. I mainly took account of quality improvement of the report when I assessed systems processing personal informations. So, I propose in terms of logical validity improvement of assessment report. The improvements on 4 different outputs for each phase are many cases that I assessed systems processing personal informations. And I propose improvements on qualified assessors having capability of GRC and on process for managing the assessment system. To settle down PIA system as the reasonable and effective assessment system even after 2016, the statutory deadline for completion of PIA, assessors and appointed assessment firms and authorities should cooperate to complete the assessment system.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.22 no.2
• /
• pp.279-294
• /
• 2011

This research reports the results from the pilot evaluation of academic libraries in Korea conducted from September through November 2010 to test the applicability and feasibility of an evaluation model and evaluation indicators developed by this research team. In the first and second stages of this pilot evaluation, quantitative and qualitative indicators were respectively used, and in the third stage a survey for user satisfaction was conducted. Out of 58 applicants which applied for this evaluation, a total of 9 libraries were selected as excellent libraries for each group classified according to the size of a library(large, medium, and small) in 3 areas of specialization and 1 library was awarded the best performed library. Despite such limitations as the use of experimental indicators and a pressing schedule, there were some positive effects including the use of formal statistics, an objective assessment of current status of academic libraries, and the improved interest of university administration in academic libraries.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.13 no.1
• /
• pp.63-69
• /
• 2003

The main property of VSC is that the system response is robust and insensitive to parameter variations and external disturbances in the sliding mode if their bounds are known to the designer of the system control. But sometimes these bounds may not be easily obtained. However, fuzzy control provides an effective way to design the controller of the system with the disturbances and parameter variations. Therefore, combination of the best feature of fuzzy control and sliding mode control is considered. When using the conventional VSC, generally the reaching phase problem occurs, which cause the system response to be sensitive to parameter variations and external disturbances. In order to overcome these problems, a robust position control method of the BLDC motor using an adaptive fuzzy VSC without leaching phase is presented.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.305-309
• /
• 2006

Construction management system has been needed to be anchored and revitalize in these days, since it was entered into a domestic market. We could consider application of CM services as a challenge of construction project system and a way to get to an advanced nation in construction field. Application of CM services could be possible in public projects by a regime. However, in case of private construction projects, it is hard to apply it without understanding of substantial necessity and propriety. so in this study, we find a application method of CM services to private small-midium construction projects, and make CM services item table of CM services for revitalization by examining the cases that applied to in private small-medium construction projects.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.11C
• /
• pp.1527-1540
• /
• 2004

In this paper, velocity measurement of fast moving object for traffic information acquisition using line sampling of image is proposed. Velocity measurement for traffic information acquisition of moving object is that the first sample line and second sample line on the road is set, then car is detected by using difference image method between time-variance hue data of image when car is passing two sample lines and hue data of the reference image, and velocity of the car is measured by using frame number of video which is occupied by two sample lines. Identification of the car is performed by hue of the detected car between the first sample line and second sample line, respectively To examine the propriety of the proposed algorithm, identification and velocity measurement for driving car is evaluated. The evaluated results is that it is identified by hue data of car passing two sample lines, and the velocity measurement for driving car is less than 3% comparing with X-band speed gun.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.6
• /
• pp.132-141
• /
• 2019

1990s, Construction market continued to grow in South Korea exceeding 20% of GDP. In 2015, more than 30 years of old multi-family dwellings amounted to 4.93 million and it continues to increase until 2019. In Particular, the share of Public rental Housing accounts for 90.6% of South Korea's Total aging housing. Before checking the feasibility of Construction Project Management such as Renovation and Reconstruction, Checklists were presented through price impact factor analysis and analysis of housing construction system(Regulation). Based on 32 Price Influencing factors and 20 Indicators based on the housing construction system The Construction project management seems appropriate. As a result, the 22 complexes were found to be suitable for remodeling. This study is meaningful enough to be used for Domestic rental Housing construction and Construction project management and to suggest specificity. Future Research is needed to Quantify the checklist.

• Journal of Korean Society of Transportation
• /
• v.17 no.4
• /
• pp.33-44
• /
• 1999

LED(Light Emitting Diodes)는 반도체를 이용한 발광소자로서 동화상 광고물이나 가변정보표지판(VMS)등에 주로 활용되고 있으며 최근 외국의 경우 LED 기술을 교통신호등에 적용하여 시범설치 및 확대 적용 설치하여 운영 중에 있으며 국내에서는 산업체, 학계, 연구소 등에서 연구 개발 중에 있다. 본 연구는 현재 이러한 산 학 연의 노력에 의해 개발된 LED 교통신호등을 현장에 적용하기에 앞서서 실내실험과 현장실험을 통하여 에너지 절감효과 및 현장적용성을 검증하고 경제성 분석을 통한 타당성을 제시하는 데 목적이 있다. 연구 내용으로써 기존 전구식 신호등과 LED 신호등의 발광원리 및 특징 비교 분석, 실내실험을 통한 에너지 절감효과 검증, LED 보행자 신호등 현장적용성 평가, LED 신호등으로 서울시의 기존 신호등을 연차적으로 교체하는 경우에 대한 경제적 분석이 실시되었다. 실내실험을 통해 LED 신호등의 에너지 절감효과가 평균 76% 임을 검증하였고 보행자 신호등에 대한 현장 실험에서 설문응답자의 83.7%가 LED 신호등의 시인성이 우월하다고 나타나 현장적용성은 긍정적인 것으로 나타났다. LED 신호등에 대한 경제성 분석결과 자본회수기간은 6년으로 나타났으며 향후 기존 신호등의 고장 및 유지 보수 등에 의한 차량정체 비용, 교통사고 비용 및 소자기술 발전을 고려하면 이보다 단축될 것으로 판단된다. 향후 차량등에 대한 운전자들의 반응 및 장기적인 안정성 등에 대한 종합적인 실험이 추가적으로 이뤄져야 할 것이며 이를 바탕으로 하여 LED 신호등에 대한 규격서 제정 등 법 제도 측면이 이루어진 후 LED 국내 기술 수준 등을 총체적으로 고려하여 LED 교통신호등에 대한 보급방안이 강구되어야 할 것이다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.3 no.2
• /
• pp.108-115
• /
• 1991

This paper aims at the elucidation of the characteristics of longshore current profile after wave breaking. Wave breakers are always accompanied by complex turbulent process, wave energy losess occur and the mean water level also varies due to the gradient of radiation stress. These with other factors result in the development of longshore currents. Longshore currents have relations to the alongshore sand transport and to the diffusion of contaminants in nearshore region, thus the understanding and elucidation of them are very important from the engineering point of view. Using the calculated results, the factors such as lateral mixing cofficients, bed shear stress. wave angle. wave steepness and bottom slope. which are influencing the longshore current profile. are examined. Also, by comparing the results of longshore currents with the experimental data obtained by other investigators, the procedure proposed in the present study is shown to be valid.