• 한국건설순환자원학회논문집
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• 제5권1호
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• pp.21-28
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• 2017

최근 원자력 발전소 및 LNG 탱크의 외벽을 제작하는데 있어 강판 콘크리트(steel-plate concrete, SC)와 같은 합성형 구조모듈(steel-plate concrete panel, SCP)의 사용이 증가하고 있다. SCP는 공장에서 생산 한 후 이송되므로, 이송에 드는 비용을 줄이기 위해 경량화가 필수적이다. 이때 경량골재 콘크리트를 사용해 SCP의 내부를 채워 밀도를 낮출 수 있지만, 현재 콘크리트 배합법은 콘크리트의 품질을 확보하기 위해 경량골재의 사용량이 제한되어 경량화에 한계가 있다. 본 연구에서 제안하는 프리플레이스트 경량 콘크리트 배합법은 거푸집 내 경량골재를 먼저 채운 후(pre-packing) 그라우트를 주입하는 공법으로, 콘크리트의 품질확보 및 밀도를 낮출 수 있다. 다양한 종류의 경량골재 및 그라우트 배합을 사용해 실험을 수행하였고, 밀도 $1,600kg/m^3$, 압축강도 30MPa급 프리플레이스트 경량 콘크리트 배합비를 선정하여 SCP 시편을 제작하였다. 제작된 SCP 시편의 구조성능 시험을 위해 3점 휨 실험을 수행하였다. 고유동 콘크리트를 사용해 SCP의 내부를 채운 시편과 비교해 프리플레이스트 경량 콘크리트를 사용해 제작된 SCP 시편은 비슷한 수준의 휨 저항 성능을 보였으며 밀도가 30% 이상 낮았다. 따라서 프리플레이스트 경량 콘크리트를 사용해한 SCP 제작 시, 기존의 SCP와 비슷한 수준의 구조성능을 가지며 밀도를 낮춰 이송 비용을 감축할 수 있을 것으로 기대된다.

• Current Photovoltaic Research
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• 제9권2호
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• pp.31-35
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• 2021

Shingled module shows high ratio active area per total area due to more efficient packing without inactive space between cells. The module is fabricated by connecting the pre-cut cells into the string using electrically conductive adhesives (ECA). ECAs are used for electric and structural connections to fabricate the shingled modules. In this work, we investigated a correlation between ECA peel strength and the efficiency of pre-cut 5 cells module which are fabricated according to ECA interconnection conditions. The curing conditions are varied to determine whether ECA interconnection properties can affect module properties. As a result of the peel test, the highest peel strength was 1.27 N/mm in the condition of 170℃, the lowest peel strength was 0.89 N/mm in the condition of 130℃. The efficiency was almost constant regardless of the curing conditions at an average of 20%. However, the standard deviation of the fill factor increased as the adhesive strength decreased.

• 한국정밀공학회지
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• 제15권2호
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• pp.99-106
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• 1998

In this paper, we have constructed an expert system for semiconductor chip encapsulation which combines a knowledge-based system with CAE software. The knowledge-base module includes heuristic and pre analysis knowledge for evaluation and redesign. Evaluation of the initial design and generation of redesign recommendations can be developed from the rules as applied to a given chip package. The CAE programs can be used for simulating the filling and packing stage of encapsulation process. The expert system is a new tool which enables package design or process conditions with high yields and high productivity.

• The Journal of Advanced Prosthodontics
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• 제4권4호
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• pp.248-253
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• 2012

Maxillary obturator prosthesis is the most frequent treatment option for management of partial or total maxillectomy. Heavy weight of the obturators is often a dislocating factor. Hollowing the prosthesis to reduce its weight is the well established fact. The alternate technique to hollow-out the prosthesis has been described in this article which is a variation of previously described processing techniques. A pre-shaped wax-bolus was incorporated inside the flasks during packing of the heat-polymerized acrylic resin to automatically create the hollow space. The processing technique described is a single step flasking procedure to construct a closed-hollow-obturator prosthesis as a single unit. To best understand the technique, this article describes management of a patient who had undergone partial maxillectomy secondary to squamous cell carcinoma rehabilitated with a hollow-obturator prosthesis.

• 한국멀티미디어학회논문지
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• 제12권4호
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• pp.608-615
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• 2009

RFID 기술의 발전으로 태그 가격이 급속도로 낮아짐에 따라, 더 세밀하게 제품을 관리하기 위해 각 태그가 포장상자에만 부착되는 것이 아니라 개별 제품에 부착된다. 그러나 RFID 데이터를 처리하는 판독기와 미들웨어가 한정된 하드웨어 자원을 가지고 있기 때문에, 초대용량의 태그 데이터를 신속하게 처리하기 위한 방법들이 필수적이다. 본 논문에서는 이러한 요구조건을 효율적으로 충족시키는 새로운 이동 에이전트 기반 분산형 소프트웨어 도구를 설계하고 구현한다. 이 도구는 명시된 데이터 수집 정책을 포함한 이동 에이전트를 다수의 이동식 판독기들로 전송함으로써, 필요한 데이터가 제품의 운송 중 반복적으로 전 처리 될 수 있도록 하는 편리한 환경을 제공한다. 이러한 수행 형태는 목적지에 도착한 후 매우 많은 양의 태그 데이터를 고정식 판독기에서 처리하는 기존 방식에 비해, 판독기와 미들웨어에서 매우 높은 인식률로 태그 데이터를 처리하기 위해 요구되는 소요시간을 상당히 줄일 수 있다.

• 한국표면공학회지
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• 제45권6호
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• pp.248-256
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• 2012

A Pd-based hydrogen membranes for hydrogen purification and separation need high hydrogen perm-selectivity. The surface roughness of the support is important to coat the pinholes free and thin-film membrane over it. Also, The pinholes drastically decreased the hydrogen perm-selectivity of the Pd-based composite membrane. In order to remove the pinholes, we introduced various surface pre-treatment such as alumina powder packing, nickel electro-plating and micro-polishing pre-treatment. Especially, the micro-polishing pretreatment was very effective in roughness leveling off the surface of the porous nickel support, and it almost completely plugged the pores. Fine Ni particles filled surface pinholes with could form open structure at the interface of Pd alloy coating and Ni support by their diffusion to the membrane and resintering. In this study, a $4{\mu}m$ surface pore-free Pd-Cu-Ni ternary alloy membrane on a porous nickel substrate was successfully prepared by micro-polishing, high temperature sputtering and Cu-reflow process. And $H_2$ permeation and $N_2$ leak tests showed that the Pd-Cu-Ni ternary alloy hydrogen membrane achieved both high permeability of $13.2ml{\cdot}cm^{-2}{\cdot}min^{-1}{\cdot}atm^{-1}$ permation flux and infinite selectivity.

• 대한영양사협회학술지
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• 제19권3호
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• pp.236-252
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• 2013

The purpose of this study was to assess the microbiological quality of home-delivered meals during production and delivery for children from low-income families. Production flows from a facility in Seoul that provides home-delivered meals were analyzed and the time-temperature of the food was measured. Microbiological assessment was performed for the production environment, personal hygiene, and food samples at each production and delivery step based on the process approach. It took 2 hours or longer from completion of production to meal delivery. An aerobic colony count (ACC) and coliform were not detected at knives, cutting boards, and dish towels. However, ACC (at pre-preparation, preparation, and packing areas) and coliform (at the preparation area) were detected on the hands and gloves of employees. Air-borne bacterial counts varied according to day and preparation area (ND~6 CFU/plate/15 min). Food temperatures, on the completion of production and meal delivery, fell into temperature danger zones. ACC and coliform counts of raw ingredients did not decrease after pre-preparation (washing and sanitizing) for menus involving food preparation with no cook step. ACC decreased after cooking step for menus of food preparation with cook step, but the ACC of the stir-fried and seasoned dried filefish fillet on the completion of cooking was too numerous to count due to improper heating. The ACC of seasoned young Chinese cabbages (a menu with complex food preparation) increased during delivery (from 2.5 log CFU/ml to 5.0 log CFU/ml). This qualitative assessment of foodborne pathogens revealed that B. cereus was detected in vegetable and meat product menus. These results suggest time-temperature control is necessary during production and delivery and management guidelines during production of home-delivered meals are provided for safe production.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권4호
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• pp.317-320
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• 2016

A 47-year-old woman was referred for surgical treatment of osteomyelitis of the mandible. She had already undergone three previous surgeries. Pre-anesthetic airway evaluation predicted a difficult airway, due to the thin, retro-positioned mandible, tongue, and atrophic changes in the lips and soft tissue. We inserted packing gauzes in the buccal mucosa for easier mask fitting and ventilation. During direct laryngoscopic intubation with a nasotracheal tube (NTT), fracture of a thin mandible can easily occur. Therefore, we used a fiberoptic bronchoscope to insert the NTT. After surgery, we performed a tongue-tie to protect against airway obstruction caused by the backward movement of the tongue during recovery. The patient recovered without any complications. We determined the status of the patient precisely and consequently performed thorough preparations for the surgery, allowing the patient to be anesthetized safely and recover after surgery. Careful assessment of the patient and airway prior to surgery is necessary.

• 한국재료학회지
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• 제21권3호
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• pp.156-160
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• 2011

FePt nanoparticles suspension was synthesized by reduction of platinum acetylacetonate and decomposition of iron pentacarbonyl in the presence of oleic acid and oleyl amine. FePt nanoparticles were coated on a substrate by convective assembly from the suspension. To prevent the coalescence during the annealing of FePt nanoparticles double convective coatings were tried. First convective coating was for silica particle assembly on a silicon substrate and second one was for FePt nanoparticles on the previously coated silica layers. It was observed by scanning electron microscopy (SEM) that FePt nanoparticles were dispersed on the silica particle surface. After annealing at $700^{\circ}C$ for 30 minutes under nitrogen atmosphere, FePt nanoparticles on silica particles were maintained in a dispersed state with slight increase of particle size. On the contrary, FePt nanoparticles that were directly coated on silicon substrate showed severe particle growth after annealing due to the close-packing of nanoparticles during assembly. The size variation during annealing was also verified by X-ray diffractometer (XRD). It was suggested that pre-coating, which offered solvent flux oppose to the capillary force between FePt nanoparticles, was an effective method to prevent coalescence of nano-sized particles under high temperature annealing.

• 한국식품조리과학회지
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• 제28권4호
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• pp.391-397
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• 2012

본 연구는 소포장 양배추 김치의 품질특성에 미치는 전 발효조건의 영향을 살펴보고자 하였다. 양배추 김치 제조 후 $20^{\circ}C$에서 0, 18, 24, 28시간동안 전 발효기간을 거친 후 소포장한 양배추 김치를 각각 PF0, PF18, PF24, PF28이라 하고 $10^{\circ}C$ 저장기간 중 품질특성을 비교한 결과, PF24와 PF28의 pH은 저장 2일째에 pH 4.47과 pH 4.23을 나타내어 전 발효시키지 않았던 PF0보다 3일정도 숙성시간을 단축할 수 있었다. 총산도는 담금 직후 0.26-0.29%였으나 PF0의 경우 저장 8-14일, PF18은 3-10일, PF24와 PF28은 비슷하게 2-3일 저장 시에 잘 익은 김치가 되었다. 염도는 각 처리구와 시기별 큰 차이를 보이지 않았으나 전배양시간이 길었던 PF24와 PF28은 저장후기에 약간 증가하는 경향을 보였다. 젖산균은 전 발효조건과 상관없이 모든 처리구에서 시간이 지날수록 젖산균 수가 증가하였다. 그러나 전 발효시간을 길게 한 것일수록 젖산균수가 증가하는 속도는 더 빠르게 나타났으며 저장 후기에는 대부분 7.2-7.4 log CFU/mL로 비슷한 수준을 나타냈다. 전 발효에 따른 소포장 양배추 김치의 체적변화는 전 발효를 시키지 않았던 PF0가 저장 후기에 2.1배증가로 가장 큰 변화를 보였고 전 발효를 시켰던 시험군은 1.5-1.8배로 PF0보다 낮은 수준을 나타냈다. 관능특성은 전 발효 유무나 시간에 대한 색이나 질감의 유의적 차이는 없었으나 그 외 향, 맛, 종합적 기호도에서 일부 저장기간에 유의적 차이를 나타냈다. 향은 저장 2일과 3일에 PF28에서 우수하게 나타났고 맛은 PF24와 PF28에서 2-3일 저장했을 때 6.27-6.67로 높은 점수를 보였다. 연구결과를 종합하면, 잘 익은 소포장 양배추 김치를 상품화하고 포장재 팽창문제를 완화하는 조건으로 PF24나 PF28가 적절하다고 판단되나, 상업적 생산을 위한 대량생산은 한 번에 처리하는 시료의 양이 많기 때문에 향후 제품개발을 위해서 산업현장에서의 검토가 이루어져야 할 것이다.