• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.2
• /
• pp.150-152
• /
• 2000

The investigation of electroantennogram (EAG) using insect antennad has been primarily focused on the measurement of insect pheromone. Insect has highly specialized olfactroy receptors inside their antennae. In this paper, EAG was applied to detect general oborants and the feasibility of this system for the olfactroy biosensor was investigated. Electroantennogram measurement was carried out using the antennae of male silkworm moth, bombyx mori, and ammonia gas as the model odorant. EAG parametres including peak ampiltude increased linearly with the ammonia concentration and the reproducible electrical signals were generated at least for 2 hrs after the antenna was cut off from the sulkworm moth.

• Food Science of Animal Resources
• /
• v.38 no.1
• /
• pp.143-151
• /
• 2018

The effects of proteolytic enzymes (bromelain and bromelain+papain) and a ginger extract were assessed on collagen content and solubility, thermal shrinkage temperature of connective tissue, pH, cooking loss, drip loss, and Warner-Bratzler shear force (WBSF) of M. pectoralis profundus isolated from the beef brisket cut. Both proteolytic enzymes and ginger extract led to a significant increase in cooking loss and collagen solubility compared with untreated controls. On the other hand, the peak ($T_p$) thermal shrinkage temperature markedly decreased in all treatments compared with those in controls. Samples treated with bromelain, bromelain + papain, and ginger extract showed a significant decrease in WBSF by 36%, 40%, and 37%, respectively, compared with untreated controls. Our findings suggest that ginger extract are useful for post-mortem tenderization of meat containing high levels of collagen, compared to control even though, bromelain and bromelain + papain treatments have higher collagen solubility than ginger extract.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.692-697
• /
• 2001

Of two photovoltaic systems such as stand-alone type and utility interactive one, the utility interactive systems are so valuable for power peak-cut particularly in summer season. For the maximum power point tracking(MPPT) by which the generating energy can be maximized, many control methods have been reported up to now. To overcome the disadvantages of the conventional ones, a new MPPT algorithm is proposed which can improve both tracking ability and generating efficiency of photo voltaic system without chopper.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.1 s.178
• /
• pp.89-96
• /
• 2006

In this study, fabrication of the large area silicon mirror is accomplished by anisotropic wet etching using micromachining technology for implementation of integrated slim optical pickup and the process condition is also established for improving the mirror surface roughness. Until now, few results have been reported about the production of highly stepped $9.74^{\circ}$ off-axis-cut silicon wafers using wet etching. In addition rough surface of the mirror is achieved in case of tong etching time. Hence a novel method called magnetorheolocal finishing is applied to enhance the surface quality of the mirror plane. Finally, areal peak to valley surface roughness of mirror plane is reduced about 100nm in large area of $mm^2$ and it is applicable to optical pickup using infrared wavelength.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.12
• /
• pp.44-51
• /
• 2004

In a micro-EDM, it is well known that an RC circuit is suitable as a discharge circuit because of its low pulse width and relatively high peak current. To increase machining speed without changing unit discharge energy, charge resistance should be decreased. But, when the resistance is very low, continuous (or normal) arc discharge occurs, electrode wear increases and machining speed is reduced remarkably. In this paper, an RC circuit with transistors is used in a micro-EDM. Experimental results show that the RC circuit with transistors can cut off a continuous (o. normal) arc discharge effectively if the duty factor and switching period of the transistor are set up optimally. Through experiments with varying charge resistances, it is shown that the RC circuit with transistors has about two times faster machining speed than that of an RC circuit.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.8
• /
• pp.24-30
• /
• 1998

A blue LED of $In_{x}Ga_{1-x}N$ multiple quantum well structure which had the blue emission spectrum of donor-acceptor pair transition generated form Si-Zn co-doped $In_{x}Ga_{1-x}N$ active layer, was fabricated. The $In_{x}Ga_{1-x}N$ MQW heterojunction LED structure was grown by MOCVD on the sapphire substrate with (0001) surface orientation at 800.deg. C. The fabricated LED exhibited forward cut-in voltage of 4~4.5V and reverse breakdown voltage of -13V. Its optical chracteristics showed that the center wavelength of peak emission occurred at 460nm and the optical intensity was increased linearly with respect to the injected electrical current above 5mA.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.9
• /
• pp.1575-1580
• /
• 2010

Demand Response is a well-known means usually operated by the system operator(SO) or the electricity retailers in order to reduce the peak loads or cut the price in electricity market. KPX(Korea Power eXchange), the SO in Korea has been operating the demand bidding program(or the demand resource market) since it was firstly introduced as the pilot project in 2008. The results has proved to be effective to enhance demand response. This paper describes the basic concepts and the operation results of the program.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.9
• /
• pp.109-117
• /
• 2003

With development of high advanced technologies and skills, micro machining techniques also are being more functional and smaller. Some of the recently developed micro machining technologies are micro drilling, micro EDM, WEDG, LBM, micro milling, micro UVM etc. In these micro machining techniques, Micro -EDM is generally used for machining micro holes, pockets, and micro structures in difficult-cut-materials. For machining micro structures, first of all, tool electrode should be fabricated by WEDG process. In micro-EDM, parameters such as peak current, pulse width, duration time are very important to fabricate the tool electrode and micro structures. Developed experimental equipments are composed of RLC circuit with PWM. In this paper, using developed micro EDM machine, the characteristics of micro electro discharge machining are investigated at micro holes, slot, and pocket machining etc. Also the trends of tool wear are investigated in case of hole and slot machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.405-409
• /
• 2003

We explored a new rough grinding technique on optics materials such as Zerodur. The facility used is a NANOFORM-600 diamond turning machine with a custom grinding module and range of diamond resin bond wheel. The grinding parameters such as workpiece rotation speed depth of cut and feed rate were altered while grinding the workpiece surfaces of 20m in diameter. Surface roughness is measured by Form Talysurf series2. Our target is to define grinding conditions producing the surface roughness better than 0.02${\mu}{\textrm}{m}$ Ra and the form accuracy of around 0.2${\mu}{\textrm}{m}$ PV.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.537-538
• /
• 2015

전기혜택을 받지 못하는 개발도상국의 도서지역이나 산간지역 등에 전기를 공급하기 위한 방법으로 마이크로그리드를 구축하고 있다. 그러나 24시간 전기 공급을 위해서는 많은 투자 재원이 필요하다. 따라서 본 논문에서는 첨두 부하를 삭감하여 공급지장을 감수하더라도 투자 재원을 줄여 전기 공급의 확대를 목표로 한다. 또한 HOMER 프로그램을 이용하여 첨두 부하 삭감을 고려하는 가상발전기 개념을 도입하고 발전기의 고장정지율을 고려한 감도 분석을 통하여 마이크로그리드의 각 설비별 기대 적정 규모를 구하는 방법론을 제안한다.