• 한국기계가공학회지
• /
• 제13권6호
• /
• pp.119-126
• /
• 2014

Micro-holes of conductive ceramic are required in micro structures. Micro-electrical discharge machining (Micro-EDM) is an effective machining method since EDM is as process for shaping hard metals and complex-shaped holes by spark erosion in all kinds of electro-conductive materials. However, as the depth of micro hole increases, the machining condition becomes more unstable due to inefficient removal of debris between the electrode and the workpiece. In this paper, micro-EDM was performed to evaluate machining characteristic such as electrode wear, machining time, taper angle, radial clearance with varying voltage and ultrasonic vibration on 10 vol.% Carbon-nanotube reinforced conductive $Al_2O_3$ composite fabricated by spark plasma sintering in previous research.

• 융합신호처리학회논문지
• /
• 제3권1호
• /
• pp.74-79
• /
• 2002

많은 제어기법들이 이산시간영역제어계에서 제어성능을 개선하기 위해서 제안되고 있다. 이 제어기법들을 이용한 제어계에서 계의 응답특성은 제어기의 이득에 관계한다. 특히 외란이나 부하변동에 의해서 계의 응답이 변할 때 제어기의 이득을 재조정할 필요가 있다. 본 논문에서는 다층 신경망으로 I-PD제어기와 전치보상기를 설계하였다. I-PD제어기와 전치보상기의 이득이 자동적으로 역전파 알고리즘에 의해서 조정되도록 하였다. 제어계의 응답이 어떤 조건에 의해서 변할 때 I-PD제어기와 전치보상기의 이득들이 역전파 알고리즘에 의해서 자동적으로 조정되게 하였다. 이 I-PD제어기법을 직류 서보 전동기를 구동원으로 하는 위치제어계에 적용하여 제어기의 제어성능을 실험 결과로 타당성을 확인하였다.

• 융복합기술연구소 논문집
• /
• 제7권2호
• /
• pp.13-16
• /
• 2017

The design of sealing mechanisms of a manual pressure valve was analyzed with FE analysis for a hydrogen fuels charge and discharge system of FCEV. The damage prediction of the O-ring with respect to the material models of rubbers was calculated by the gap analysis of the backup ring and O-ring according to the internal pressure. Two kinds of the rubber material characteristic models were adopted to the O-ring. One was the linear elastic and the other was hyperelastic of Ogden $3^{rd}$ order model. The experimental data of urethane of Shore hardness 90 was utilized to the curve fitting of hyperelastic properties. It was found that the contact pattern of the backup ring was different in two models and the sealing mechanism was better in the case of the hyperelastic characteristic model.

• 대한안전경영과학회지
• /
• 제22권2호
• /
• pp.73-82
• /
• 2020

IEC 60079-10-1 edition 2.0, the global standard for hazardous area classification, was newly revised in 2015. There are many differences compared to the previous edition 1.0 version, first released in 2008, so it has caused confusion in the industry. In case of edition 1.0, the hazardous area extent can be derived through the mathematical formula, but in case of edition 2.0, there was the problem that the exact hazardous area extent was not known because of the mathematical formula of the plot for applying the hazardous area extent was not presented. In this study, we converted the plot introduced in edition 2.0 to CAD format and derived the plot as the mathematical equations. Through this, we suggest the hazardous area extent formula of three states (heavy gas, diffusive, jet). As the IEC committee did not provide the mathematical formula of the hazardous area extent according to the release characteristic, it is impossible to apply the exact hazardous area extent. In this study, a mathematical approach was derived for the plot introduced in edition 2.0, which can reduce the confusion of the applying hazardous area extent.

• 식품보건융합연구
• /
• 제8권5호
• /
• pp.1-9
• /
• 2022

The health of modern people is threatened by bad eating habits. In order to provide healthy desserts to people, we conducted a study on adding plum concentrate, which is effective for fatigue recovery, insomnia, and prevention of constipation, to scones. In order to examine the utility of scones made by adding plum concentrate, the following experiment was conducted. It was prepared by adding 0g, 3g, 5g, and 7g of plum concentrate to the scone dough, respectively. As a result of the test, the sensory characteristic value was the highest in the experimental group to which 5 g of plum concentrate was added (4.77). There was a significant difference in that the average value tended to increase as the concentration of the plum concentrate increased. As for fragrance, the experimental group with the addition of 5 g of plum concentrate showed the highest sensory characteristic value of 3.62, but there was no significant difference. The experimental group to which 3 g of plum concentrate was added showed higher preference than the control group in most items such as color, flavor, sweetness, and overall preference. This study suggests that the production of scones with plum concentrate has a high potential for commercial use.

• 한국산업융합학회 논문집
• /
• 제27권3호
• /
• pp.591-599
• /
• 2024

This paper presents the configuration and characteristic analysis of the protection system to improve the safety of the building integrated photovoltaic(BIPV) system. BIPV is a solar power system installed in buildings. Since the BIPV system is installed in buildings, there is a high risk of electric shock and fire accidents. Therefore, in order to improve the safety of BIPV, a protective system is required to block or quickly detect risk factors. In this paper, as a protection system to improve the safety of the BIPV system, it is composed of a rapid shutdown (RSD) that can quickly separate the PV system to prevent fire and electric shock accidents and a system to detect Arc faults that cause PV system fires. RSD and Arc Fault Detector analyzed the operating characteristics according to each condition and confirmed that the safety of the BIPV system can be improved through this.

• 디지털융복합연구
• /
• 제10권5호
• /
• pp.143-154
• /
• 2012

본 연구에서는 창업의도에 영향을 미치는 요인을 창업성과와 창업특성 요인들이 창업의도에 미치는 영향을 살펴보았다. 이 과정에서 창업특성 각 차원들이 창업의도에 미치는 영향에 대한 창업성과의 매개효과를 검정하고자 하였다. 실증결과 본 연구에서 사용된 창업특성과 창업성과가 창업의도에 유의한 정(+)의 영향을 알 수 있었다. 그리고 창업성과의 매개효과를 검증한 결과 창업성과는 매개효과가 있는 것으로 검정되었다. 이와 같은 결과는 창업성과에 대한 요인이 창업의도에 매출과 순이익이 영향을 미치는 것으로 나타났다. 특히, 창업특성인 성취욕구, 위험감수성, 사업전략이 창업의도 간의 영향관계를 확인하였다는 데 의의가 있다. 이 연구를 위하여 K공과대학교, K대학교, 대구 Y전문대학, J(사(社))직장인들을 대상으로 설문조사 및 연구결과를 도출하였다. 특히, 미 창업자들의 관점에서 창업특성, 창업성과, 창업의도에 대한 영향관계 확인에 시사점을 제공한다.

• 패션비즈니스
• /
• 제22권5호
• /
• pp.64-82
• /
• 2018

As sustainability of fashion brands is becoming more important in the prolonged depression, the fashion market is also seeking ways to create new value through convergence with various fields. In the fashion market, convergence marketing is engaged with diverse technologies combined with advanced technologies and strategies. This study established the conceptual characteristics of convergence and divergence from a market perspective. Convergence can be summarized as Borderless, Compounding, Diversification, Recombination and Affiliation. The conceptual characteristics of the divergence can be summarized as de-fusion, individualization, differentiation, specialization, and segmentation. The characteristics of convergence revealed through the case of fashion market include the expandability of the new category, the expandability of the consumer, the brand experience, and the expandability of time and space. Divergence is the differentiation of brand value, target customer, and product nature. Through this study, we could understand the differentiation of the fashion market and the direction of the marketing strategy by looking at the characteristic of the convergence marketing - oriented research that has the contrary conceptual characteristics from the extended viewpoint. Based on this, it is possible to see the changes and patterns of brand marketing strategies and techniques in recent fashion market. In the future, it is expected that the systematic study of the marketing strategy of the domestic fashion brand based on the convergence and change characteristics of the fashion market proposed in this study will continue.

• 한국전자파학회논문지
• /
• 제22권9호
• /
• pp.852-857
• /
• 2011

본 논문에서는 이중 대역 대역 통과 여파기 설계에 이용 가능한 가변 특성 임피던스 전송 선로의 응용을 제시하였다. 제안된 여파기는 고정된 첫 번째 통과 대역과 가변 가능한 두 번째 통과 대역을 갖는다. 스터브 부하공진기(Stub Loaded Resonator: SLR)는 직렬 공진기와 개방 단락 스터브로 구성되는데, 개방 단락 스터브를 결함 접지 구조(Defected Ground Structure: DGS) 전송 선로와 바랙터 다이오드로 구현함으로써 두 번째 통과 대역의 조정이 가능하다. 제안된 구조의 타당성을 보이기 위해 3개의 전송 영점을 갖는 2단 이중 대역 대역 통과 여파기를 설계하였고, 이론적인 예측값과 시뮬레이션 결과를 실험적으로 증명하였다.

• 융합신호처리학회논문지
• /
• 제13권1호
• /
• pp.39-43
• /
• 2012

점대점 통신용의 60GHz 대역 무선 송수신기를 NRD(Non-Radiative Dielectric) 도파관 구조로 제작하였다. NRD 도파관을 구성하는 유전체 선로의 경우 재질이 무르기 때문에 정밀 가공이 쉽지 않고, 또 온도에 따른 수축팽창이 심해 공진 특성이 중요한 소자에 사용하기에 는 적합하지 않았다. 또한 NRD 도파관 구조로 증폭모듈을 구성하는 것이 어려웠는데, 본 논문에서는 위에서 언급된 문제를 극복 하고자 다음과 같은 방법으로 송수신기를 제작하였다. 기본적으로 NRD 도파관 구조를 유지하되, 공진특성이 중요하지 않은 소자들은 NRD 도파관 하이브리드 IC로, 공진특성이 중요한 소자들은 도파관으로 제작하고, 증폭기는 MMIC를 패키징하여 모듈화한 후에 NRD 도파관 내에 장착되도록 하였다. 제작된 송수신기는 FDD(Frequency Division Multiplexing) 방식으로 통신하며, 10dBm의 송신출력과 -60dBm의 최소 수신감도를 갖고 있다.