• KIEAE Journal
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• v.3 no.3
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• pp.19-25
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• 2003

The Address No.0 of Eco-friendly Architecture offers unique experience for those who visit the place to envisage the future architecture where nature, human and building exist in harmony. It is open to the general public including the students of elementary and secondary schools. This house has been built to provide opportunities for the general public to experience eco-friendly architecture. It's floor area is 42 pyung($140m^2$) and the overall site has the area of 180 pyung($600m^2$). The following illustrates some of its prominent features : ${\bullet}$ Remodeling of a traditional Korean residence ${\bullet}$ Application of passive solar systems ${\bullet}$ Use of clerestory windows and daylighting systems(washroom and machine room) ${\bullet}$ Operation of solar water heaters with flat plate collectors ${\bullet}$ Construction of Biotop(small ecological world) ${\bullet}$ Water circulation for Biotop by photovoltaic(150W) and wind power(400W) generation ${\bullet}$ Outdoor hot water supplied by all-glass evacuated solar tubes. Through this Address No.0 of Eco-friendly Architeture conclusions are as followings. 1. The array of tubes in collector has the best nice in that the number of tube is nine and the tilt angle is the latitude $+20^{\circ}$. 2. The thermal performance of the all-glass solar vacuum collector was excellent than of the flate-plate solar collector. 3. The adaption of new small wind power systems to buildings were proved to produce a profit if it is considered the expense of environment improvement and the wind speed increasing according to rise of building hight.

• Journal of the Korean Vacuum Society
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• v.20 no.2
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• pp.114-126
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• 2011

The light propagation along a long positive column has been observed in a cold cathode fluorescent lamp. The optical signals are observed with the DC and AC voltage power during lamp operation. The light propagating is observed in the operation with the DC-rippled voltage as well as the AC-voltage. The optical signals propagate from the high voltage side to the ground. These signals show two kinds of features according to the before and after Townsend breakdown. At the dark current before Townsend breakdown, the optical intensity is damped and the propagation velocity is $10^4{\sim}10^5m/s$. At the high current of normal glow after Townsend breakdown, the propagation velocity is 1$10^5{\sim}10^6m/s$ without damping.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.143-143
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• 1999

Co/Ti 다층 박막을 제조하기 위해 직류원 마그네트론 스퍼터링 시스템을 이용하여 (100)실리콘 단결정 기판위에 Co와 Ti층을 각각 2/2, 5/5, 10/10 nm 정도의 두께로 조절하여 세가지 조성의 Co/Ti 다층 박막을 제조하였다. 이러한 Co/Ti 다층 박막의 후속 열처리는 Ar 가스분위기 하에서 Tube furnace를 이용하여 20$0^{\circ}C$와 30$0^{\circ}C$, 40$0^{\circ}C$의 온도에서 진행하였다. 증착초기에서부터 후속 열처리 공정을 진행하는 동안, Co/Ti 다층 박막에서의 계면반응을 미세 구조 변화 및 전기, 자기적 특성변화와 연관지어 관찰하였다. Co/Ti 다층 박막의 결정 구조와 미세 구조 변화를 관찰하기 위해 각각 X-선 회절기와 투과 전자 현미경을 사용하였고, 다층 박막의 전기적, 자기적 특성 변화를 관찰하기 위해 각각 4점 탐침기, 진동 시료형 자속계를 이용하였다. Co/Ti 다층 박막을 20$0^{\circ}C$의 저온에서 열처리를 한 경우에는 증착 초기의 계면반응에 의해 형성된 비정질 층이 성장하였고, 30$0^{\circ}C$와 40$0^{\circ}C$의 고온에서 열처리를 하는 경우에는 비정질 측의 성장보다는 새로운 화합물 CoTi 결정상이 형성되면서 비정질상은 오히려 감소하였다. 즉, Co/Ti 다층 박막의 계면 반응은 결정질 Co와 Ti을 계면 반응물로 소모시키면서 비정질 층을 성장시키는 비정질화 반응이 활발히 일어났다. 특히, 소모된 계면 반응물로 소모시키면서 비정질 층을 성장시키는 비정질화 반응일 활발히 일어났다. 특히, 계면 반응물로 소모시키면서 비정질 층을 성장시키는 비정질화 반응일 활발히 일어났다. 특히, 소모된 계면 반응물 Co와 Ti 중에서 Ti의 소모속도가 더 빠르게 관찰되었다. 이로부터 Ti 이 증착초기에서 저온 열처리 과정동안 Co/Ti 다층 박막의 계면에서 일어나는 비정질화 반응의 주 확산자로 작용했다는 것을 알 수 있다. 한편, 30$0^{\circ}C$와 40$0^{\circ}C$의 고온에서 열처리한 Co/Ti 다층 박막의 계면 반응은, 비정질 반응에 의한 비정질층의 형성보다는 새로운 화합물 결정질 CoTi상을 형성시키는 결정화 반응이 우세했다. Co/Ti 다층 박막의 전기적 저항은, 열처리에 의한 비정질 층의 생성 및 성장으로 인해 증가하였고 새로운 저저항 CoTi 결정상의 형성으로 인해 감소하는 것을 알 수 있었다. 또한 Co/Ti 다층 박막의 포화 자화값은, 열처리에 의한 계면에서의 비정질화 반응과 CoTi 결정화 반응으로 인해 강자성체인 Co 결정상이 감소됨에 따라 감소하는 경향을 나타냈다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.91-91
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• 2010

현재 나노크기의 나노소자에 대한 관심과 연구가 활발히 진행 중에 있고, 나노소자 제작을 위한 나노구조체 연구에도 탄력을 받고 있다. 나노구조체 연구 중에서도 탄소나노튜브(CNT)와 실리콘이 많이 연구되고 있으나 CNT의 경우 금속과 반도체 등 전기적 특성이 혼재되어 분리기술이 필요하며, 실리콘 기반의 나노구조체들은 공기 중에 노출되었을 경우 자연 산화막 생성에 대한 문제점들이 대두되고 있다. 이러한 기존 나노구조체들의 문제점들을 극복하기 위해 산화물 계열의($InO_3$, ZnO와 $SnO_2$ 등) 나노구조체들이 화학, 광학 및 생화학 센서등의 다양한 응용 연구들이 진행되고 있다. 본 연구에서는 thermal evaporation법으로 tube furnace 장비를 이용하여 온도($500{\sim}900^{\circ}C$)변화에 따른 ZnO nanorod를 성장시켰다. 성장된 ZnO nanorod의 구조적 특성을 확인하기 위하여 전계방출주사전자현미경(SEM)을 측정한 결과 ZnO nanorod들은 직경 50~80nm, 길이는 400~1000nm 이상까지 다양한 직경과 길이를 가지고 성장되었으며 $800^{\circ}C$ 에서 성장된 ZnO nanorod가 가장 곧고 이상적인 nanorod의 형태를 이루는 것을 확인할 수 있었다. Nanorod는 온도가 높아질수록 nanowire로 성장됨에 따라 본 연구에서 $800^{\circ}C$ 에서는 nanorod형태를 이루고 있으나 $900^{\circ}C$에서부터 nanowire의 형태로 성장되었다. 또한 성장된 ZnO nanorod들의 X-선 회절패턴(XRD)을 측정 결과 ZnO의 (002) 우선 배양성 때문에 성장된 nanorod 또한 (002) 방향으로 성장되었음을 확인하였다. 이 연구를 통하여 온도를 조절함으로서 ZnO nanorod의 성장제어가 가능함을 확인하였고, 특성 분석을 통하여 발광소자, Solar Cell로의 응용가능성을 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.435-435
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• 2010

A inclined slot-excited plasma source is newly designed and constructed for higher flux HNB(Hyperthermal Neutral Beam) generation. The present source is different from the vertical SLAN(SLot ANtenna) sources [1] in two aspects. One is that the slots are inclined, and the other is that the magnetic field is configured to a cusp type. These modifications are intended to make the source plasma operated in sub-milli-torr pressure regime and as thin as possible, both of which is to get higher HNB flux by decreasing the re-ionization rate of the reflected atoms from the neutralizer [2]. The plasma is generated in a quartz tube of internal diameter 170 mm enclosed in a aluminum application chamber of larger diameter 250 mm. The microwave power is fed to the plasma chamber by 8 inclined slots cut into the application chamber wall. The slots are coupled the chamber to a WR280 waveguide wound around it to form a ring resonator. In order to make two slots $\lambda_g/2$ apart in phase, the adjacent slots are rotated in opposite directions. The rotation angle of the slots are set to $60^{\circ}$ from the chamber axis. Between the quartz chamber and the aluminum cylindrical chamber 8 NdFeB magnets are equally spaced and fixed to form the cusp magnetic field confinement and ECR (Electron Cyclotron Resonance) field. In this presentation, the magnetic and electromagnetic simulations, and the measured plasma parameters are given for both the inclined and the vertical slot-excited plasma sources. We also discuss how the sources can be tailored to suit better-performing HNB sources.

• Journal of the Korean Vacuum Society
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• v.22 no.4
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• pp.204-210
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• 2013

In order to improve osseointegration for biomedical implants, it is crucial to understand the interactions between nanostructured surfaces and cells. In this study, $TiO_2$ nanowires were prepared via Vapor-Liquid-Solid (VLS) process with Sn as a metal catalyst in the tube furnace. Nanowires were grown with $N_2$ heat treatment with their size controlled by the agglomeration of Sn layers in various thicknesses. MC3T3-E1 (pre-osteoblast) were cultured on the $TiO_2$ nanowires for a week. Preliminary results of the cell culture showed that the cells adhere well on the $TiO_2$ nanowires.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.176.2-176.2
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• 2013

Property of optical diagnostics for pulse-discharged plasma in liquid and its biological applications to proteins are investigated by making use of high voltage Marx generator. The Marx generator has been consisted of 5 stages, where each charging capacitor is 0.5 ${\mu}F$, to generate a high voltage pulse with rising time of $1{\mu}s$. We have applied an input voltage of 6 kV to the each capacitor of 0.5 ${\mu}F$. High voltage pulsed plasma has been generated inside a polycarbonate tube by a single-shot operation, where the breakdown voltage is measured to be 7 kV, current of 1.2 kA, and pulse width of ~ 1 ${\mu}s$ between the two electrodes of anode-cathode whose material is made of tungsten pin, which are immersed into the liquids. We have investigated the emitted hydrogen lines for optical diagnostics of high voltage pulsed plasma. The emission line of 656.3 nm from $H-{\alpha}$ and 486.1 nm from $H-{\beta}$ have been measured by a monochromator. If we assumed that the focused plasma regions satisfy the local thermodynamic equilibrium conditions, the electron temperature and density of the high voltage pulsed plasma in liquid could be obtained by the Stark broadening of optical emission spectroscopy. For the investigation of the influence of pulsed plasma on biological proteins, we have exposed it onto the proteins such as hemoglobin and myoglobin. The structural changes in these proteins and their analysis have also been obtained by circular dichroism (CD) and ultraviolet (UV) visible spectroscopy.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.324-331
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• 2013

All evacuated tube collector is being constantly studied since it can reduce the conductive heat loss in absorber by using vacuum technology and has advantage of heat transport capacity and quick thermal response in comparatively small temperature difference. This study investigated the dynamic thermal performance of the solar collector with the control condition of solar irradiance and fluid temperature by using performance experimental apparatus which is combined with solar collector and refrigerator, examined the thermal characteristics in definite temperature range of fluid in constant temperature tank by simultaneously measuring refrigerating performance. As a result of it, I deducted the related equation of collector efficiency and found that mean collector efficiency has increased through quick heat transfer characteristics according to increase of outdoor temperature and irradiance in case of outlet temperature of constant temperature tank $22^{\circ}C$ when set outlet temperature of solar collector $25^{\circ}C$ with outlet temperature of constant temperature tank $18^{\circ}C$ & $22^{\circ}C$. Also COP of refrigerator was acquired value of 6.2~7.1 at outlet temperature of constant temperature tank $18^{\circ}C$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.421-431
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• 2016

The purpose of this study was to identify the influence of depression, social isolation, and meaning in life on the swallowing related quality of life in patients with dysphagia. In this study, 87 the dysphagia patients diagnosed with stroke, degenerative disease, and neurological disorder in a general or rehabilitation hospital in Seoul, Gyeonggi, and Incheon were assessed. The data were collected between February and April, 2015 using CES-D, RULS, PIL, SWAL-QOL. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation, and stepwise multiple regression with SPSS 22.0. Of the participants, 20.7% reported having had depression, 92.0% middle-high social isolation and 64.4% existential vacuum. The mean scores were SWAL- QOL 158.89(35.97). Stepwise multiple regression revealed that tube feeding to have the greatest effect on SWAL-QOL(${\beta}=-0.57$, p<.001), followed in order by age (${\beta}=0.26$, p=.001), lower MIL (${\beta}=0.19$ p=.014), and education (${\beta}=0.17$, p=.032). The most influential factor to SWAL-QOL was tube feeding. These variables accounted for 50.7% of SWAL-QOL in dysphagia patients (F=28.84 p=.031). Therefore, it is essential to develop the intervention that can improve the meaning in life in patients with dysphagia. In addition there is a need to study the psychological factors and quality of life of tube feeding.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2309-2314
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• 2007

The application analysis of bubble pump on the domestic solar water heater system is presented. The system investigated in this study is a passive device, self pumping and self regulating. It was test to use the bubble pump on solar water heater system. The test experiment has been taken on the existed vacuum tube about the efficiency, working fluid temperature and pressure and circulated power. In order to check the working temperature and working pressure effectively, the bubble pump was test separated from the solar water heater. The equipment consists of the bubble pump, heater and heat exchanger. The main structure of bubble pump was design depend on the character of two phase flow. The complete system was instrumented to measure pressures, temperatures and flow-rates at various locations. The theory analysis of design bubble pump has been given and the experiment design has been included in the paper.