• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1038-1041
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• 2003

In the paper, we investigated silicon surface microstructures formed by reactive ion etching in hollow cathode system. Wet anisotropic chemical etching technique use to form random pyramidal structure on <100> silicon wafers usually is not effective in texturing of low-cost multicrystalline silicon wafers because of random orientation nature, but High density hollow cathode plasma system illustrates high deposition rate, better film crystal structure, improved etching characteristics. The etched silicon surface is covered by columnar microstructures with diameters form 50 to 100nm and depth of about 500nm. We used $SF_{6}$ and $O_{2}$ gases in HCP dry etch process. This paper demonstrates very high plasma density of $2{\times}10^{12}$ $cm^{-3}$ at a discharge current of 20 mA. Silicon etch rate of 1.3 ${\mu}s/min$. was achieved with $SF_{6}/O_{2}$ plasma conditions of total gas pressure=50 mTorr, gas flow rate=40 sccm, and rf power=200 W. Our experimental results can be used in various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications. In this paper we directed our study to the silicon etching properties such as high etching rate, large area uniformity, low power with the high density plasma.

• 한국디지털건축인테리어학회논문집
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• 제11권4호
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• pp.5-11
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• 2011

The present study investigated the actual conditions of physical therapy rooms at long-term hospitals in Korea and conducted a comparative analysis to develop an efficient floor plan and facility improvement measures. 1. At hospitals surveyed, physical therapy services were used at a high frequency but they did not have enough space for rehab treatment and long paths of patient flow were found to make patient management inconvenient. Therefore, physical therapy units should be conveniently located both in terms of distance and direction so as to be accessible from patient rooms or wards. The space should be organized in a concentrated layout for efficiency of physical therapy, and floor planning for therapy units should ensure the best possible viewing angle to therapists. 2. With regard to the disease characteristics of patients, many physical therapy rooms were in difficult circumstances because of poor facilities, so they need to secure skilled personnel, supplement apparatuses and equipment and have rooms for functional recovery, hydrotherapy and operation treatment. In addition, each of the curtained or partitioned areas for treatment should be set up with consideration for the amount of space taken up by medical equipment. The area under each bed should be designed for patient convenience so that it can be used as storage space for patient's belongings and shoes. 3. Patients complained about the lack of physical therapy space, resting places or exercise areas and demanded the expansion of rehab programs and facilities. Physical therapy facilities need to be improved for patient privacy and effective natural ventilation. 4. At most of the long-term hospitals surveyed, physical therapy units were found to have small areas and treatment equipment and devices were insufficient compared to the number of patients. Therefore, it is required to secure more space (at least 138.24 sq. meters per 100 beds) and improve facilities for better physical therapy services.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.645-649
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• 2009

Liquid desiccant cooling technology can supply cooling by using waste heat and solar heat which are hard to use effectively. For compact and efficient design of a dehumidifier, it is important to sustain sufficient heat and mass transfer surface area for water vapor diffusion from air to liquid desiccant on heat exchanger. In this study, the plate type heat exchanger is adopted which has extended surface, and hydrophilic coating and porous layer coating are adopted to enhance surface wettedness. PP(polypropylene) plate is coated by porous layer and PET(polyethylene terephthalate) non-woven fabric is coated by hydrophilic polymer. These coated surfaces have porous structure, so that falling liquid film spreads widely on the coated surface foaming thin liquid film by capillary force. The temperature of liquid desiccant increases during dehumidification process by latent heat absorption, which leads to loss of dehumidification capacity. Liquid desiccant is cooled by cooling water flowing in plate heat exchanger. On the plate side, the liquid desiccant can be cooled by internal cooling. However the liquid desiccant on extended surface should be moved and cooled at heat exchanger surface. Optimal mixing and distribution of liquid desiccant between extended surface and plate heat exchanger surface is essential design parameter. The experiment has been conducted to verify effective surface treatment and distribution characteristics by measuring wall side flow rate and visualization test. It is observed that hydrophilic and porous layer coating have excellent wettedness, and the distribution can be regulated by adopting holes on extended surface.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.22-22
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• 2010

주물과 용접에서 응고 과정에서 수지상간 또는 세포상간 영역에서 최종적으로 응고하는 저융점 공정 조성의 상이 응고균열의 발생에 직접적으로 영향을 미친다. 작은 량의 공정조성의 액상 필름이 응고된 고상과 고상 사이에 존재하게 되면 이 영역에서 생성되는 불연속부는 응고균열로 남게 된다. 이러한 공정조성 액상의 유동성이 좋고 충분한 부피로 존재한다면 응력과 부피수축등으로 생성된 수지상간, 또는 세포상강 영역에서 생성된 불연속부로 용이하게 유동하여 불연속부를 충진하게 된다. 따라서 발생한 응고균열이 치유되는 효과를 얻을 수 있다. 반면에 공정조상의 상이 전혀 존재하지 않는 순금속 응고의 경우에는 최종 응고 단계에 액상 필름이 존재하지 않게 되어 고상과 고상의 인터로킹이 가능하게 되어 균열 발생 가능성이 희박하다. 따라서 응고균열 발생을 제어할 수 있는 효과적인 방법은 용탕이나 용접금속의 조성을 공정 조성에 가깝게 제어하는 것이다.

• 한국환경과학회지
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• 제26권12호
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• pp.1341-1353
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• 2017

This study aimed to identify the aquatic and riparian factors associated with the presence/absence of the Eurasian otter in the Nakdong river basin, where the species is relatively more abundant than other otter species. Environmental factors and presence records were collected. Geographical Information System technology and chi-square test were used to compare environmental gradients in aquatic and riparian factors between presence and absence sites. Aquatic habitat attributes were evaluated with natural riverside sandbars and channel crossing artificial structures, the ratio of channel width to alluvial plain width, riverbed substrate, and flow diversity. Riverbank characteristics, bank materials, man-made embankment types, and land use/land cover of inland and riverside areas were selected as riparian habitat attributes. Compared to the aquatic attributes, riparian attributes were highly significant when assessing otter presence and absence sites, suggesting that conservation of suitable riparian areas to provide maternity and resting areas for otter species is essential in the Nakdong river basin. None of the aquatic attributes examined were statistically significant when evaluating otter presence or absence. These results indicate that the presence of suitable riparian area for resting and reproduction habitats is more critical to the presence of Eurasian otter than food availability in aquatic areas. To inform implementation of effective conservation actions, broad-scale factors, such as watershed attributes, would be needed to further assess habitat conditions of the Eurasian otter.

• 한국항해학회지
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• 제18권3호
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• pp.81-103
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• 1994

Increasing costs and competition in the global trade and transportation arena have led to a search for effient, cost-effective, particularly through the application of computer and information technologies. Most recently the introduction of Electronic Data Interchange(EDI) technologies in both trading and trade facili-tation activitiess have bagun to change the complextion of the international transport space. Korea as well as the other developing countries has become aware of the need to embrace EDI strate-gies in order to maintain a competitive market position with their more technologically advanced neighbou-ring and international trading partners. A way of EDI implementation, KMPA has invested large budgets in the research of the EDI since 1990. As the result of study in EDI of transport, KL-Net(Korea Logistics Network) was organized for the EDI business in cargo logistics. In spite of these KMPA's activities, the development plan of container logistics data interchange is not good and useful. So a new model of EDI in transportation is required by using the concepts of cargo data sharing. The purpose of this paper is to suggest a new way of container logistics data interchange model. This paper therefore analyze the information flow in the current container logistics and find the problem in the area to derive a new model. The followings are the results of this paper : (1) There are many problems and user's requirements in container logistics data interchange in Korea. (2) Many messages of UN/EDIFACT are able to be used in container logistics data interchange. (3) The container cargo data are stored in Container Logistics Network(CL-Net) database. And when necessary by requesting message transmission, the container logistics data interchange is possible. (4) Customs cargo clearance system and PORT-MIS can be linked to CL-Net. If the systems, however, are to introduce EDI in data interchange, the quality of user's software has to be assured.

• 한국유체기계학회 논문집
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• 제18권3호
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• pp.38-45
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• 2015

In this study, two computational methodologies were compared to consider an effective conjugate heat transfer analysis technique for the cooled vane with thermal barrier coating. The first one is the physical modeling method of the TBC layer on the vane surface, which means solid volume of the TBC on the vane surface. The second one is the numerical modeling method of the TBC layer by putting the heat resistance interface condition on the surface between the fluid and solid domains, which means no physical layer on the vane surface. For those two methodologies, conjugate heat transfer analyses were conducted for the cooled vane with TBC layer having various thickness from 0.1 mm to 0.3 mm. Static pressure distributions for two cases show quite similar patterns in the overall region while the physical modeling shows quite a little difference around the throat area. Thermal analyses indicated that the metal temperature distributions are quite similar for both methods. The results show that the numerical modeling method can reduce the computational resources significantly and is quite suitable method to evaluate the overall performance of TBC even though it does not reflect the exact geometry and flow field characteristics on the vane surface.

• 산업경영시스템학회지
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• 제40권2호
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• pp.60-67
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• 2017

A baggage handling system (BHS) in airport is an unified system for moving the passengers' baggage in designated time. Input baggage from the check-in counter travels to the baggage claim area or cargo handling terminal through this system. In particular, entryway BHS consists of conveyors, X-ray and sorters such as tilt-tray to send the baggage to departing airplane and it could have various problems for handling certain amount of baggage in restricted time such as baggage jamming at certain merge point. This causes systemic error such as delay of the time, omissions of the baggage and even breakdown of the equipment and inefficiency. Also the increasing maximum time of the baggage passing through the BHS could delay the flight schedule and finally decrease the service level. Thus, the algorithm for controlling the flow of the merge is essential to the system. The window reservation algorithm is the one of the most frequently used methods to control the merge configuration. Above all, the reserve location, so called reserve ahead point, that allocates the window is important for the performance of the algorithm. We propose the modified window reservation algorithm and the best reserve locations by changing the reserve ahead point in the induction conveyors. The effect of various reserve ahead points such as the capacity and utility of the system were analyzed and the most effective reserve ahead point combination was found. The total baggage processing time and the utilization of the tilt-tray are properly considered when choosing the optimal Reserve ahead point combination. In the layout of this study, the configuration of four conveyors merged into one tilt-tray is studied and simulation analysis is done by AutoMod(R), 3D simulation software. Through the simulation, the window reservation algorithm is effectively operated with the best combination of reserve ahead point which reduces the maximum baggage travel time.

• 대한정형도수물리치료학회지
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• 제15권2호
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• pp.93-97
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• 2009

Anatomy: Facet joint syndrome most often affects the lower back and neck and refers to pain that occurs in the facet joints, which are the connections between the vertebrae in the spine that enable the spine to bend and twist. Many physicians have believed that the usual lesion of facet syndrome was an anatomical impairments of facet joint itself.. Facet joint injection using local anesthetics is a reliable method for the diagnosis and treatment for facet syndrome. Etiology: One of many possible causes is imbalances that can occur in stress levels, hormone levels, and nutritional levels. These imbalances can adversely affect posture, which can lead to neck and back pain. The common disorder called facet syndrome exhibits lower back pain, with or without, radiating pain to buttock and thigh due to facet joint arthropathy. Pain in the facet joint is supposedly the secondary effect of narrowing of joint space by sustained muscle contracture around joints. Syndrome: Facet joint syndrome tends to produce pain or tenderness in the lower back that increases with twisting or arching the body, as well as pain that moves to the buttocks or the back of the thighs. Other symptoms include stiffness or difficulty standing up straight or getting out of a chair. Pain can be felt in other areas such as the shoulders or mid-back area. Treatment: Non-drug treatments include hot packs, ultrasound, electrical stimulation, and therapeutic exercises. Stimulating blood flow using massage or a hot tub may also help. Alternative treatments include yoga and relaxation therapy. If your pain persists after trying these treatments, a surgical procedure called radiofrequency rhizotomy, which destroys the sensory nerves of the joint, may bring relief. Facet joint injection has been helpful in diagnosis and therapy for this facet syndrome. Radiofrequency thermocoagulation of medial branches is known to be an effective method of relieving pain caused by facet joint problems. We conclude that spasmolytic treatment of muscles connecting the two vertebral articular space would be better for treatment and diagnosis of facet syndrome rather than facet block with local anesthetic and steroid only.

• 대한전자공학회논문지TC
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• 제41권7호
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• pp.9-19
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• 2004

무선 랜 환경에서 신뢰성 있는 멀티캐스트 프로토콜을 지원하기 위해서는 에러 복구와 흐름 제어와 같은 기능이 필요하다. 유선과 무선의 비대칭적인 상호작용으로 인해 발생하는 큐잉 손실과 제한된 무선 채널의 대역폭은 패킷 손실을 줄일 수 있는 효율적인 방법을 필요로 한다. 그리고 공유되는 하나의 브로드캐스트 매체를 사용하기 때문에 여러 수신 단말로부터 동시에 피드백 정보가 전송단에 전달되면 전송단의 채널 혼잡과 과부하를 야기 시킬 뿐만 아니라 순방향의 데이터 프레임 전송을 지연시키게 된다. 그러므로 수신 단말로부터 전송되는 피드백 정보의 수를 줄이는 방법이 필요하다. 본 논문에서는 무선 랜 멀티캐스트 환경에서 채널 상태를 고려하는 적응적 FEC(Forward Error Correction) 방법과 ARQ(Automatic Repeat Request) 방법을 사용하여 역방향 채널의 피드백 수와 재전송 횟수를 줄이고 높은 데이터 신뢰성을 제공할 수 있는 ARS(Adaptive Redundancy Scheme) 방법을 제안한다. 제안하는 방법의 성능을 수학적 분석과 AWGN과 레일리 페이딩(Rayleigh fading) 채널 환경에서의 모의실험 결과를 통해 평가하였다. 성능 평가 결과, 제안하는 방법이 기존의 FEC와 ARQ를 사용하는 방법에 비해 비슷한 효율을 유지하면서 피드백 정보의 수와 재전송 횟수를 줄이고 높은 데이터 신뢰성을 제공하는 것을 확인하였다.