• 한국식품저장유통학회지
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• 제16권3호
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• pp.321-326
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• 2009

마이크로버블을 이용한 세척시간과 세척방법에 따라 처리한 상추의 세척효과와 저장 중 품질 변화를 살펴본 결과는 다음과 같다. 세척시간 설정을 위한 실험을 통해 마이크로버블로 1, 3, 5분간 세척하여 미생물변화, 관능검사, 세척된 정도를 측정한 결과 5분간 처리한 시료가 가장 좋은 결과를 나타냈다. 세척방법에 따라 전처리한 상추의 미생물 변화는 세척처리 한 직후 무세척(CT)구는 4.30 log CFU/g, 손세척(HW)구는 4.10 log CFU/g, 일반버블세척(BW)구는 3.98 log CFU/g, 마이크로버블세척(MW)구는 3.25 log CFU/g에서 저장 10일째에는 무세척(CT)구는 7.00log CFU/g, 손세척(HW)구는 6.19 log CFU/g, 일반버블세척(BW)구는 6.02 log CFU/g, 마이크로버블세척(MW)구는 5.89 log CFU/g로 마이크로버블처리구가 가장 적은 변화를 보였다. 관능검사에서는 일반버블세척(BW)구와 마이크로버블세척(MW)구가 무세척(CT)구와 손세척(HW)구보다 유의적으로 높게 평가되었으며, 일반버블세척(BW)구와 마이크로버블세척(MW)구는 유의적 차이를 보이지 않았다. 또한 잔류농약시험에서도 마이크로버블을 이용한 처리구가 대조구 보다 2-3배정도 제거효과를 보였다. 상추의 세척상태를 측정한 결과 손세척구와 일반버블처리구은 완전히 깨끗하게 세척되지 못한 반면 마이크로버블처리구는 이물질이 보이지 않아 세척효과가 큰 것으로 나타났다.

• 정보저장시스템학회논문집
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• 제1권2호
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• pp.115-120
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• 2005

As a popularity of a portable digital device such as a cellular phone, a digital camera and a MP3 player is spreading, the demand of the mobile storage device increases rapidly. A bluray technology using 405nm laser diode and objective lens having high NA(Numerical Aperture), 0.85, satisfies a miniaturization and a high capacity which are the requirements of the portable device. To develop SFFOP(small form factor optical pickup), it is prerequisite to minimize the number of optical components and establish evaluation and assembly method of micro optical pickup system as well as mass production method of micro optical component. To minimize optical elements of optical pickup, there have been many researches to use P-HOE(Polarized Holographic Optical Element) due to its extremely small size and versatile function. However, P-HOE is handled and assembled very accurately in SFFOP. In this paper, static error signal detection method is developed for an alignment of P-HOE in SFFOP. Using developed static error signal detection method, P-HOE can be aligned very accurately with real time result of static error signals of pickup such as FES(focusing error signal) and TES(Tracking Error Signal). The developed static error signal detection method is verified by the evaluation of commercialized DVD Pickup. And finally. developed static error signal detection method is applied for the assembly of P-HOE in SFFOP system satisfies specification of BD(Blu-ray Disk).

• 한국융합학회논문지
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• 제6권1호
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• pp.29-34
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• 2015

점차 스마트그리드 기술이 발전됨에 따라서 에너지의 효율성에 이목이 집중되고 있다. 그래서 스마트그리드를 구성하고 있는 마이크로그리드 내의 에너지를 독립적으로 관리하기 위해서는 신재생에너지에 대한 연구를 필요로 한다. 그중에서도 소수력 에너지는 마이크로그리드내의 사용자가 사용하는 물의 양에 따라서 그 어디에도 설치 할 수 있는 장점을 가지고 있다. 사용자들이 주거하는 아파트, 공동주택에서 사용하고 있는 하수량을 기반으로 전기 발전량과 발전기의 가동률을 측정하여 측정값이 소수력 발전에 적합한지 알아본다. 적합한 아파트, 공동주택에서는 위치에너지를 활용하여 발생한 하수를 소수력 발전기로 전기를 생산 한다. 마이크로그리드의 에너지 관리 시스템과 전기 저장 장치를 도입하여 보다 효율적인 관리를 제안하고자 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.357-360
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• 2002

Nowadays, the improvement and development of Multi-media, information and communication technology are rapidly processed. And many products, for example, digital camera, digital camcorder, and PDA, are used for them. They need large data storage capacity and small size, light storage system. Due to that, many studies and researches in data storage system have been carried out. Especially, micro drive system was presented by IBM.(1) However, its system is expensive and uneasy to be portable. In ODD technologies, 1 inch drive system is not yet or in processing status.(2) If to be possible and to be come up, it is cheap than HDD system and easy to transfer information. In this paper, a miniaturized actuator(about linch) is designed and tested for ODD system. Specially, it is adapted for NFR(Near-field Recoding) system using SIL(Solid Immersion Lens). It is the dual-servo actuator which consists of a coarse actuator and fine actuator. Its actuating force generation method is VCM(Voice Ceil Motor). The fine actuator has 4-wire suspensions and bobbin wrapped by coil and includes focusing motion as well as tracking motion. The coarse actuator has an actuating coil and V-grooved guide mechanism. Also, the characteristics of the designed actuator is estimated by sine-swept mode and LDV(Laser Doppler Vibro-meter).

• 정보저장시스템학회논문집
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• 제6권1호
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• pp.37-40
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• 2010

Fresnel lens is a kind of refractive optical lens with various advantages. It has nearly flat shaped optical lens that has small mass. Fresnel lens has number of applications in the compact optical systems. Recently, demands of high quality Fresnel lens for small size optical systems such as illumination units, compact imaging systems, display units, information storage systems, optical detecting units had increased rapidly. Conventional manufacturing process of high quality Fresnel lens is direct machining. However, it is not suitable for mass production because of high cost and long cycle time. Replication method can provide cost effective mass production process. However, there are various issues about replication of Fresnel lens. Fresnel lens has number of sharp blade shape prism. In the replication process, this blade shape causes defects that can affect optical efficiency. In this study, replication processes; injection molding process and UV imprinting process, were developed and evaluated using Fresnel lens that has maximum pattern height of $250\;{\mu}m$ and aspect ratio of 1.5.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.79-82
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• 2005

Fresnel lens has number of applications in the optical systems because of its advantages. It is nearly flat lens that has small weight. It is conventionally used in lighthouse beacons, condensing unit of overhead projector and etc. Recently, demands of small size optical systems such as display units, information storage systems, optical detecting units had increased. Conventional manufacturing process of high quality Fresnel lens is direct machining. But it is not suitable for mass production because of high cost and long cycle time. Replication process is more suitable for mass production. But the Fresnel lens has number of sharp blade shape prism. In the replication process, this blade shape causes defects that can affect optical efficiency. In this study, replication process of blade shape pattern that has maximum height of $280{\mu}m$, aspect ratio 1.4 for Fresnel lens application.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 추계총회,초청강연,특별강연,연구발표회
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• pp.204.1-204
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• 2000

• 전기의세계
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• 제26권1호
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• pp.71-76
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• 1977

It has been expected that the 4th generation computers will be characterized for their problem adaptability. There are few techniques of implementing such a characteristic. One of the techniques that one have considered in this paper the user microprogrammable computer architecture. There are two different computer architectures that support user microprogramming. One uses the writeable control storage and another uses the main memory. The concept of utilizing writeable control storage for microprogramming was developed in 1950's and since then the most of the user microprogrammable computers produced belong to such category. The concept of utilizing the main memory for user microprogramming was first introduced by Thomas in 1973. This architecture has a strong advantage in the aspect of the system cost. In this paper, we have developed a user microprogrammable computer. The computer utilizes the main memory for user microprograms. It employs a 32 bit micro-instruction word in the form of the little encoded. The performance of the developed machine will be evaluated in the hard ware cost, programming easiness and the running time.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.75-80
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• 2005

Study for toner adhesion is known as an important role in electrophotography. In this research, a centrifugal detachment method was used to measure the adhesion force of several hundred particles simultaneously and to determine its sensitivity to particle size. For uncharged toner particles, we estimated the van der Waals force based on the centrifugal farce experiments. Then for charged toner particles, the centrifugal force experiments were carried out. The difference between the results for charged toner particles and the results for uncharged toner particles was compared with the image force calculated from a model which assumed that the toner charge was located at the center of the particle. In the calculations, experimental data obtained by E-SPART (Electrical- Single Particle Aerodynamic Relaxation Time) analyzer were used. The adhesion force of micro-sized toner particles deposited on the DR surface was found to be approximately 1${\~}$3 nN.

• 소성∙가공
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• 제15권1호
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• pp.3-8
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• 2006

The demand fer small and high-capacity optical data storage devices has rapidly increased. The areal density of optical disk is increased by using higher numerical aperture objective lens and shorter wavelength source. A wafer-scale stacked micro objective lens with a numerical aperture of 0.85 and a focal length of 0.467mm for the 405nm blue- violet laser was designed and fabricated. A diffractive optical element (DOE) was used to compensate the spherical aberration of the objective lens. Among the various fabrication methods for micro DOE, the UV-replication process is more suitable fur mass-production. In this study, an 8-stepped DOE pattern as a master was fabricated by photolithography and reactive ion etching process. A flexible mold was fabricated for improving the releasing properties and shape accuracy in UV-replication process. In the replication process, the effects of exposing time and applied pressure on the replication quality were analyzed. Finally, the surface profiles of master, mold and molded pattern were measured by optical scanning profiler. The geometrical deviation between the master and the molded DOE was less than $0.1{\mu}m$. The diffraction efficiency of the molded DOE was measured by DOE efficiency measurement system which consists of laser source, sample holder, aperture and optical power meter, and the measured value was $84.5\%$.