• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 추계학술대회논문집
• /
• pp.94-99
• /
• 2000

When operating NC lathe, gear box which is equipped with gear train and spindle sometimes generates loud noise and excessive vibrations. In order to identify their causes, In this study, torsional and lateral vibration characteristics including critical speeds of the gear train-spindle system are first analyzed by using torsional and lateral vibration models of the gear train and shafts. Natural frequencies and modes of the gear box structure are also analyzed by impulse hammer test. Furthermore, measured vibration and noise signals are analyzed and compared with theoretical analysis results. At last it is concluded that the cause of the excessive mise and vibration is the resonance between gear meshing frequency including its side bands, shaft bending and torsional vibration frequencies, and the natural frequencies of th gear box structure. Consequently the noise and vibration levels are greatly reduced by avoiding resonance between them through the redesign of the gear module.

• 한국산학기술학회논문지
• /
• 제11권11호
• /
• pp.4129-4136
• /
• 2010

본 논문의 목적은 가정용 냉동시스템에서 유발되는 소음 및 진동을 소음 및 진동 분석 방법에 의거하여 파악하여 궁극적으로 소음제어를 통하여 저감하는 것이며 소음저감 방안을 제공하는데 있다. 이를 위하여 다양한 냉동시스템의 작동 조건에서 구조 소음 및 유동 소음을 측정하였으며, 압축기 및 주요 구성부품들에 대한 소음 제어를 통하여 10%의 소음을 저감하였다.

• 한국지능시스템학회논문지
• /
• 제16권6호
• /
• pp.753-758
• /
• 2006

본 논문에서는 하이브리드 발전 시스템에서의 최대 전력 추종을 위한 디지털 퍼지 제어기 설계를 목표로 한다. 하이브리드 발전 시스템은 풍력과 태양광, 두 개의 발전 시스템으로 구성된다. 각 발전기에서 전압과 전류는 일반적으로 비선형 관계에 있기 때문에, 퍼지 모델 기반 제어기를 사용하여 비선형성을 효율적으로 제어하게 된다. 또한 마이크로프로세서 기반제어 시스템의 구축을 위하여 최신 디지털 재설계 기법을 사용하며, 디지털 퍼지 제어기를 설계하게 된다. 마지막으로 하이브리드 발전 시스템의 플랜트를 통한 실험으로써 본 제안 기법의 우수성을 입증한다.

• 한국전자거래학회지
• /
• 제24권2호
• /
• pp.55-70
• /
• 2019

통신 인프라 구축과 최적화를 위해서는 각 구성 요소들의 연관성을 고려할 필요가 있다. 본 논문에서는 최적화된 통신 인프라 구축을 위해 필요한 주요 고려사항을 바탕으로 성능이 향상된 MACSec 기반의 통신 인프라 구성 방안을 제시한다. 제안된 MACSec 기반 기술은 통신 인프라를 처음부터 다시 설계하지 않고 IPSec 기술을 별도의 장비를 추가하지 않고 대체할 수 있다. 아울러, 구성 시 주요 고려사항인 메시지 오버헤드와 암호화 처리 성능, 그리고 이동성 측면에서 실험을 통해 IPSec과 성능을 평가한다. 시험 결과에 따르면 MACSec으로 구현된 암호화 네트워크에서 IPSec보다 Hop 지연과 메시지 오버헤드와 같은 일반적 성능뿐만 아니라 연결 지점 변경 시험을 통해 이동성 성능이 우위에 있다.

• 기록학연구
• /
• 제54호
• /
• pp.151-178
• /
• 2017

본 연구는 기록관리 현장의 전자기록관리영역의 문제를 확인하고 IT신기술의 도입으로 인해 급변하고 있는 기록 생산 및 관리 환경의 변화에 조응할 수 있는 새로운 전자기록관리체계의 설계를 위해 과제를 도출하는 것을 목적으로 한다. 새로운 정부의 기록관리 혁신에 맞추어 프로세스, 시스템, 인프라 모든 영역에서 이전과는 다른 차세대 기록관리 개념 설계가 이루어져야 하는 시기이다. 이러한 관점에서 차세대 기록관리의 가치와 지향이 어떠해야 하는지 방향성을 도출하고 이에 따라 프로세스, 시스템, 인프라 영역의 문제를 확인하고 과제화하였다.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권1호
• /
• pp.997-1007
• /
• 2021

This study aims to redesign and find out the role of Islamic work ethics in influencing Islamic motivation, affective commitment, job satisfaction, and employee performance. Respondents in this study are populations of various cross-sectoral and cross-profession employees, such as government and private workers, soldiers, educators (teachers and lecturers) in various offices in Central Java. 220 questionnaires were distributed to all respondents, but the number of the returned questionnaires was 200. Thus, totally, this study analyzed 200 questionnaires. Data are analyzed using Structural Equation Modelling (SEM). The results show that the eight hypotheses are accepted: there is a positive and significant influence of Islamic work ethics on Islamic motivation; there is a positive and significant effect of Islamic work ethics on job satisfaction; there is a positive and significant effect of Islamic work on affective commitment; there is a positive and significant influence of Islamic motivation on affective commitment; there is a positive and significant influence of Islamic motivation on job satisfaction; there is a positive and significant effect of job satisfaction on employee performance; there is a positive and significant effect of affective commitment on employee performance; there is a positive and significant influence of Islamic motivation on employee performance.

• 정보보호학회논문지
• /
• 제7권3호
• /
• pp.65-78
• /
• 1997

DES가 Differential Cryptanalysis(이하 DC)에 쉽게 공격받을 수 있는 결정적인 취약점은 5-box를 포함한 암호함수의 구조에 있다 따라서 DES의 DC에 대한 대응방안으로는 XOR분포가 완전하게 균일(입력 XOR가 zero일 경우는 제외)하도록 5-box를 재구성하는 방법과 N-1 라운드 특성이 구성될 확률을 낮추기 위해 DES 알고리즘의 일부를 수정하는 방법을 생각할 수 있다. 그러나 Dawson과 Tavares가 제안한 완전히 균일한 XOR분포 테이블을 갖는 S-box는 오히려 균일하지 않을 매보다 더 취약하다고 Pieprzyk의 연구결과에 의해 증명되었다 결국 DES가 DC에 대응하기 위해서는 5-box의 재설계만으로는 부족하며 암호함수 자체를 수정해야 할 것이다. 본 논문에서는 DES의 암호함수를 일부 수정하여 DC에 대한 반복 특성이 구성될 확률을 낮추는 방안을 제안하고자 한다. 비교 분석 결과 제안된 알고리즘이 기존의 DES보다 DC 공격에 강함을 확인하였다.

• Architectural research
• /
• 제24권2호
• /
• pp.29-40
• /
• 2022

The transition from manufacturing to service-based economies in highly developed societies during the post-industrial period resulted in the decline of the industrial landscape, leaving it abandoned or underutilized. In pursuit of revitalizing the obsolete industrial space, innovative design techniques based on adaptive reuse are applied to retrofit modern functions to create a new cultural space and preserve the historical, symbolic, and cultural importance of the abandoned industrial facilities. Design considerations based on facade redesign have proven to be one of the most adopted techniques that can help in recreating a new function for the vacant industrial buildings and integrating them into the present-day urban fabric. This paper examines the facade renovation elements used for the adaptive reuse of 15 abandoned industrial buildings presently used as multi-purpose facilities in South Korea. Through a questionnaire survey, this study analyzes the respondents' preference for different facade renovation elements in the 15 sites according to age and gender. The study found that both genders showed similar preference patterns between most elements. But on some elements, females were keener and expressed a stronger opinion than males. There were much more females than males who perceived color and material as the most important exterior elements. The findings of this study can be used for the adaptive reuse of industrial buildings according to user preferences for different facade renovation elements.

• 대한안전경영과학회지
• /
• 제23권4호
• /
• pp.135-146
• /
• 2021

It is getting more intensified with the competition among participating companies for global market share in major industrial fields. The situation is accelerating especially within the top 5 market share, and these include electric vehicles, semiconductors, chemicals, and shipbuilding industries. The key to the advantage over the competition within a strategic group is which company leads the innovation in the field. On-the-ground innovation refers to job-based innovation. This paper aims to analyze job unit innovation in the structure of empowerment, LMX, and job crafting. Existing studies on job crafting have suggested a causal structure based on job design in the traditional sense, and there are not many scholars who study the causal structure using a job situational model. Therefore, this paper takes an approach from the perspective of the job situation. As a result of the study, LMX showed a moderating effect on the relationship between autonomy provision and job crafting. While, in the relationship between meaing-giving and cognitive crafting, there is no significant moderating effect shown on the relationship between autonomy provision and cognitive crafting. Therefore, the results of the analysis in this study suggest that the meaning of jobs and participation in decision-making should be managed in an integrated way in structural and design areas, not just qualitative factors such as empowerment and leadership.

• 방사성폐기물학회지
• /
• 제20권2호
• /
• pp.209-229
• /
• 2022

This work provided a review of three techniques-(1) spectrochemical, (2) electrochemical, and (3) spectroelectrochemical-for molten salt medias. A spectroelectrochemical system was designed by utilizing this information. Here, we designed a spectroelectrochemical cell (SEC) and calibrated temperature controllers, and performed initial tests to explore the system's capability limit. There were several issues and a redesign of the cell was accomplished. The modification of the design allowed us to assemble, align the system with the light sources, and successfully transferred the setup inside a controlled environment. A preliminary run was executed to obtain transmission and absorption background of NaCl-CaCl₂ salt at 600℃. It shows that the quartz cuvette has high transmittance effects across all wavelengths and there were lower transmittance effects at the lower wavelength in the molten salt media. Despite a successful initial run, the quartz vessel was mated to the inner cavity of the SEC body. Moreover, there was shearing in the patch cord which resulted in damage to the fiber optic cable, deterioration of the SEC, corrosion in the connection of the cell body, and fiber optic damage. The next generation of the SEC should attach a high temperature fiber optic patch cords without introducing internal mechanical stress to the patch cord body. In addition, MACOR should be used as the cell body materials to prevent corrosion of the surface and avoid the mating issue and a use of an adapter from a manufacturer that combines the free beam to a fiber optic cable should be incorporated in the future design.