• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.179-187
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• 2020

This paper investigates the construction equipment accidents by time. Construction sites are unique with many different hazardous conditions which cause accidents. According to the Occupational Safety and Health Administration (OSHA), accidents related to construction equipment are one of the most leading causes of fatal injuries in the construction industry. While there have been many studies investigating the equipment-related accidents, few research studies provided in-depth analyses about the time that accidents frequently occurred. By using the OSHA accidents data collected between 1997 and 2012, this paper analyzed the accidents data by time, equipment type including excavator, backhoe, dozer, and crane, accident cause, and injury class. The analyses revealed that the time window with most accidents was between 13:00 and 13:59. In terms of the injury class, the time windows with the highest numbers of equipment accidents were between 13:00 and 13:59 and between 11:00 and 11:59 for fatality and hospitalization, respectively. For the accident causes, equipment operator's error was the highest number of accident causes. It is expected that findings from the analyses can be used to more strategically develop management plans and guidelines to prevent accidents related to construction equipment to practitioners.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.41-47
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• 2005

This paper deals with a squeal noise in a brake system. It has been proved that the squeal noise is influenced by the angular misalignment of a disk, disk run-out, with the previously experimental study. In this study, a cause of the noise is examined by using FE analysis program(SAMCEF) and numerical analyses with a derived analytical equation of the disk based on the experimental results. The FE analyses and numerical results show that the squeal noise is due to the disk run-out as the experimental results and the frequency component of the noise equals to that of a disk's bending mode arising from the Hopf bifurcation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.173-180
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• 2011

Recently, many railway stations are built under the railway line in urban area. The passage of railway vehicles generates mechanical vibrations of a wide range of frequency. Thus, it is required to place structural vibration isolation systems to reduce vibration and noise originating from surrounding environments. This study is to investigate the maximum floating slab length based on track/floating slab interaction analyses. Actions to be taken into account include temperature, braking/acceleration, bending of the deck, and creep/shrinkage. The additional rail stress has been chosen for the criterion for the maximum slab length. In addition, further analyses are performed to include the stopper which restrict the in-plane movement of the floating slab track. Several alternatives for stopper positions were thoroughly studied in this study.

• Journal of information and communication convergence engineering
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• 제9권6호
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• pp.701-705
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• 2011

RFID is a widely adopted in the field of identification technology these days. Radio Frequency IDentification (RFID) has wide applications in many areas including manufacturing, healthcare, and transportation. Because limited resource RFID tags are used, various risks could threaten their abilities to provide essential services to users. A number of RFID protocols have done by researcher in order to protect against some malicious attacks and threat. Existing RFID protocols are able to resolve a number of security and privacy issues, but still unable to overcome other security & privacy related issues. In this paper, we analyses security schemes and vulnerability in RFID application. Considering this RFID security issues, we survey the security threats and open problems related to issues by means of information security and privacy. Neither a symmetric nor an asymmetric cryptographic deployment is necessarily used with light weighted algorithm in the future.

• Nuclear Engineering and Technology
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• 제35권5호
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• pp.442-453
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• 2003

This study investigates the safety assessment of the potential for fretting-wear damages on steam generator (SG) U-tubes caused by foreign object in operating nuclear power plants. The operating SG shell-side flow field conditions are obtained from three-dimensional SG flow calculation using the ATHOS3 code. Modal analyses are performed for the finite element modelings of U-tubes to get the natural frequency, corresponding mode shape and participation factor. The wear rate of U-tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted. Also, discussed in this study is the effect of the flow velocity and vibration of the tube on the remaining life of the tube.

• 한국조리학회지
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• 제12권2호
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• pp.106-120
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• 2006

This study aimed to analyze the effects of handbills from the food-service industry on the marketing performance. In this study, an independent variable was one of the evaluation factors of handbills while performance variables were general satisfaction of handbills and repurchase intention. For the analysis methods, frequency analysis, descriptive statistics, factor analysis and multiple regression analysis were performed with SPSS 12.0. As a result of analyses, it was revealed that general satisfaction of handbills by advertisement evaluation factors was partly significant. Second, it was found that a product purchase intention by advertisement evaluation factors was not mostly influential. Even though the findings of this study, it is expected that this study, which attempted an exploratory study on handbills of the food-service industry, will be used for future advertisement analyses of the food-service industry and as basic information on the advertisement effect.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.595-600
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• 2004

This paper deals with a cause analysis of a squeal noise in a brake system. It has been proved that the squeal noise is influenced by the angular misalignment of a disk, disk run-out, with the previously experimental study. In this study, a cause of the noise is examined by using FE analysis program(SAMCEF) and numerical analyses with a derived analytical equation of the disk based on the experimental results. The FE analyses and numerical results show that the squeal noise is due to the disk run-out as the experimental results and the frequency component of the noise equals to that of a disk's bending mode arising from the Hopf bifurcation.

• 한국정보통신학회논문지
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• 제15권6호
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• pp.1307-1312
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• 2011

RFID 는 유비쿼터스 환경하에서 필수불가결한 기술이 되도 있다. 그러나 RFID 의 본질적인 단점으로 인하여 프라이버시와 같은 보안적인 취약점을 기자고 있다. 따라서 본 논문에서는 이러한 태그에서의 취약점과 프로토콜의 위협 요소를 살펴보고, 이를 위한 실제적인 기술적인 요소에 대해서 상세히 분석하였다. 특히 현재 표준안으로 사용되고 있는 EPCglobal RFID Gen2에 적용하기 위한 보안성 향상을 위한 기술적인 방법에 대해서 분석하였다.

• 한국문헌정보학회지
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• 제47권3호
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• pp.49-72
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• 2013

본 연구는 학술연구성과의 확산을 위한 게이트웨이로서 A대학의 기관리포지터리인 A-IR의 운영정책과 이용현황을 분석하고, 접속자 수, 접속 국가, 접속 유형, 접속 빈도에 따른 이용행태, 접속 경로 등 다양한 방법으로 이용통계를 분석하였다. 이를 기반으로 A-IR에 등재된 학술연구성과물의 이용과 피인용 간의 상관관계 분석을 통하여 대학 기관리포지터리의 효과를 입증하였다.

• 한국조리학회지
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• 제14권4호
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• pp.269-282
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• 2008

Quality is recognized as one of the key components of business strategies. In this respect, this study aims to investigate quality factors that influence customer satisfaction and loyalty in Korean Tofu restaurants and promote the quality improvement in their service operations. The experimental data were collected from the questionnaire answered by 130 customers in Seoul and Kyonggi area. They were statistically analyzed using SPSS Win.12.0. For statistical analysis, frequency, factor analysis, reliability analysis, and regression analyses were conducted. The results of the analyses show that two dimensions such as "empathy" and "IT use" influence the satisfaction of customers. "Empathy", "tangibles", "well-being food", and "customer satisfaction" were identified as critical factors influencing the loyalty of customers.