• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1993년도 추계학술대회 논문집
• /
• pp.632-637
• /
• 1993

Rating systems of bevel gears(straight, spiral, and zerol bevel gears) which are commonly used as power transmission devices for non-parallel axes are developed on the personal computer, which analyze and/or evaluate the gear design and the service performance at the point of view of strength and durability. The typical considerations of the ratings are the bending strength the surface durability, and the scoring resistance. The ratings are carried out using the reliable standards of AGMA & Gleason Works. Therefore, the system is built so that the variables or factors considered differently in those standards and the strength, durability, and scoring partially in Gleason are appraised separatedly by each method, and a series of the estimation processes is integrated into the system so as to compare each result. The developed rating system can be used in the initial stage of gear design process, and also a better design can be performed by the evaluation of the initial design at the view point of gear strength and durability. Additionally, it is useful for the trouble-shooting of bevel gear systems and to the purpose of introducing the methods for maintaining design strength in service with appraising the gear strength after design or with appraising the influencing factors, as a whole. Therefore, this rating systems can help the aim of design automation of bevel gears.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.1864-1870
• /
• 2007

The inspection periods for the metro EMU maintenances vary variously according to the countries and railway operators. And the inspection systems vary according to the safety, economical, technical aspects, and also the social environments like passengers and maintenance qualities, etc. Also, in economic point of view, maintenance requires the man power, facilities, equipments, purchasing of parts and the loss of not being in revenue service during the maintenance period. Recently, there is a tendency that the inspection periods are extended gradually owing to the increased reliabilities of the equipments and parts of EMUs. Even if it is the EMUs that are already be in service, once the inspection method is innovated, the inspection time can be reduced. The inspection management innovation scheme includes such methods as the complete module to module replacement when trouble shooting a faulty parts before putting the EMU back to revenue service, the replacements of parts in complete set unit for the heavy maintenance, the establishments of exchange periods for the wasting parts, modernization of inspection equipments, introduction of RAMS for the reliability improvement and computerization of EMU maintenance management, etc. I think it is possible to optimize the inspection scopes and periods per parts and equipments by the introduction of RAMS.

• 산업경영시스템학회지
• /
• 제13권22호
• /
• pp.99-111
• /
• 1990

The first national QC Circle Convention sponsored by Industry Advancement Administration in 1975 was the beginning of employees group activity from a national point view. Subsequently some events such as the first nationwide Factory Seamaul activity small Group Convention, which was supervised by the ministry of Trading and Industry and Factory Seamanulundong promotion Center, paved the way for proliferation of the group activity through all kinds of manufacturing. Although since November 1982 these two conventions has been united, many problem have been disclosed that are against the basic principle more or less. Worker's small group activity is, essentially, a trouble shooting oriented voluntary small group within their working place to improve the surroundings creatively. In practice, however, many groups are so typical and so impetuous of the material effect that it is worried to be inclined to outform rather than contents. Effective small group activities are presumed to he successful only with labor management cooperation on the basis of human-oriented management philosophy. The small group activities are also prevalent in service sector. More derivative methods have been developed and more members are willingly participating in training programs. The small group which is basically a horizontal organization unit, promotes communication within the whole organization. In consideration of the social circumstances and traditions, the flexible model of the small group activities suitable to the corporate environment, will contribute to industrial development.

• 품질경영학회지
• /
• 제19권1호
• /
• pp.115-128
• /
• 1991

In korea, since November 1982 these two small group actvity convension (QC circle convension and Factory Saemaul activity small group convension) has been united, many problem have been disclosed that are against the basic principle more or less. Worker's small group activity is essentially, a trouble shooting oriented voluntary small group within their working place to improve the surroundings creatively. In practice. however, many group are so typical and so impetuous of the material effect that it is worried to be inclined to outform rather than contents. Effective small group activities are presumed to be successful only with labor management cooperation on the basis of human-orient management philosophy. The small group activities are also prevalent in service sector. More derivative methods have been developed and more members are willingly participating in training programs. The small group which is basically a horizontal organization unit, promptes communication within the whole organization. In consideration of the social circumstances and traditions, the flexible model of the small group activities suitable to the corporate environment, will contribute industrial development.

• 한국전자파학회논문지
• /
• 제11권6호
• /
• pp.929-938
• /
• 2000

복합구조물의 레이다 단면적 예측을 위하여 포항공과대학교에서 개발중인 컴퓨터 코드에 관한 개발과정과 검증에 관한 내용을 기술하였다. 복합구조물은 평판과 모서리로 모델링 되었으며 예측을 위한 컴퓨터 코드는 물리광학, 물리광학적 회절이론과 SBR 기법을 이용한다. 축소 모형을 제작하여 포항공대 단축거리 측정장치로 RCS를 측정하였다. 예측/측정된 결과는 RCS 패턴 및 ISAR 영상을 통하여 비교 검토되었으며 그 결과는 상당히 일치하였고 복합구조물의 국부 산란현상을 잘 설명한다. 이러한 예측 방법은 스텔스 설계와 표현인식기법연수에 직접 적용될 수 있다.

• Safety and Health at Work
• /
• 제8권1호
• /
• pp.89-93
• /
• 2017

Background: Rates of overweight and obese Australians are high and continue to rise, putting a large proportion of the population at risk of chronic illness. Examining characteristics associated with preference for a work-based weight-loss program will enable employers to better target programs to increase enrolment and benefit employees' health and fitness for work. Methods: A cross-sectional survey was undertaken at two Australian mining sites. The survey collected information on employee demographics, health characteristics, work characteristics, stages of behavior change, and preference for workplace assistance with reaching a healthy weight. Results: A total of 897 employees participated; 73.7% were male, and 68% had a body mass index in the overweight or obese range. Employees at risk of developing obesity-related chronic illnesses (based on high body mass index) were more likely to report preference for weight management assistance than lower risk employees. This indicates that, even in the absence of workplace promotion for weight management, some at risk employees want workplace assistance. Employees who were not aware of a need to change their current nutrition or physical activity behaviors were less likely to seek assistance. This indicates that practitioners need to communicate the negative effects of excess weight and promote the benefits of a healthy lifestyle to increase the likelihood of weight management. Conclusion: Weight management programs should provide information, motivation. and trouble-shooting assistance to meet the needs of at-risk mining employees, including those who are attempting to change and maintain behaviors to achieve a healthy weight and be suitably fit for work.

• 한국정밀공학회지
• /
• 제29권9호
• /
• pp.1020-1025
• /
• 2012

In this study, we fabricated the superhydrophobic and super-water-repellent surface with the micro/nano scale structures using simple conventional silicon wet-etching technique and the black silicon method by deep reactive ion etching. These fabrication methods are simple but very effective. Also we reported the droplet impact experimental results on the micro/nano-scaled surface. There are two representative impact behaviors as "rebound" and "fragmentation". We found the transition Weber number between "rebound" and "fragmentation" statements, experimentally. Additionally, we concerned about the dimensionless spreading diameters for our super-water-repellent surface. The novel characterization method was introduced for analysis including the "fragmentation" region. As a result, our super-water-repellent surface with the micro/nano-scaled structures shows the different impact behaviors compared with a reference smooth surface, by some meaningful experiments.

• 방송공학회논문지
• /
• 제24권5호
• /
• pp.765-774
• /
• 2019

본 논문에서는 다중 RGB-D 카메라의 포인트 클라우드 정합 알고리즘을 제안한다. 일반적으로 컴퓨터 비전 분야에서는 카메라의 위치를 정밀하게 추정하는 문제에 많은 관심을 두고 있다. 기존의 3D 모델 생성 방식들은 많은 카메라 대수나 고가의 3D Camera를 필요로 한다. 또한 2차원 이미지를 통해 카메라 외부 파라미터를 얻는 기존의 방식은 큰 오차를 가지고 있다. 본 논문에서는 저가의 RGB-D 카메라 8대를 사용하여 전방위 3차원 모델을 생성하기 위해 깊이 이미지와 함수 최적화 방식을 이용하여 유효한 범위 내의 오차를 갖는 좌표 변환 파라미터를 구하는 방식을 제안한다.

• International Journal of Internet, Broadcasting and Communication
• /
• 제13권3호
• /
• pp.124-129
• /
• 2021

As the 4th industrial era is in full swing, the public's interest in related technologies such as artificial intelligence, big data, and block chain is increasing. As artificial intelligence technology is used in various industrial fields, the need for research methods incorporating artificial intelligence technology in related fields is also increasing. Evidence collection among digital forensic investigation techniques is a very important procedure in the investigation process that needs to prove a specific person's suspicions. However, there may be cases in which evidence is damaged due to intentional damage to evidence or other physical reasons, and there is a limit to the collection of evidence in this situation. Therefore, this paper we intends to propose an artificial intelligence-based evidence collection system that analyzes numerous image files reported by citizens in real time to visually check the location, user information, and shooting time of the image files. When this system is applied, it is expected that the evidence expected data collected in real time can be actually used as evidence, and it is also expected that the risk area analysis will be possible through big data analysis.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
• /
• pp.17-17
• /
• 2000

The issue of reflow profiling continues to be a complex topic. The pains often associated with profiling can be reduced greatly if certain guidelines are followed and if there is a strong understanding of the variables that can be encountered during the reflow process. This paper shall discuss the appropriate guidelines and trouble shooting methods for reflow profiling, and in particular shall focus upon the benefits of implementing the linear ramp-to-spike profile. Delta T(T) is defined as the variation of temperature found on an assembly during the reflow process. Too large of a T can result in soldering defects, so to combat T a Ramp-Soak-Spike(RSS) reflow profile often is utilized. However, when using a newer-style reflow oven, the T often is minimized or eliminated, thus, the soak zone of the reflow profile becomes an unnecessary step. Because of this, the implementation of a linear Ramp-To-Spike(RTS) reflow profile should be considered. Benefits such as reduced energy costs, reduced solder defects, increased efficiency, improved wetting, and a simplification of the reflow profile process may be experienced when using the RTS profile. Included in this paper are the suggested process parameters for setting up the RSS and RTS profiles and the chemical and metallurgical reactions that occur at each set point of these profiles. The paper concludes with a discussion and pictures of several profile-related defects. Each of these defects is described, analyzed, and instructions are given for troublshooting these defects.