• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.185-192
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• 2003

This study presents the Optimum Evaluation of PS Concrete Deck and High Strength Two Plate Girder System. Recently, for the simplification of structure and the long length of bridge, a small number girder bridge which minimized a number of girder by two is much designed and constructed. For the structural analysis, a finite element formulation considering with even the matter of torsion in the three-dimensional problem is presented. And connectively, for the design of optimum section, an algorithm of optimum design is developed. The section of a small number girder bridge which constituted of two girders and PS Concrete Deck is optimized by using optimum program developed in this study. and two girders bridge refered in this study is proved a efficiency and a economy by being compared and checked to the general plate girder bridge with five girder and Reinforced Concrete Deck.

• 상하수도학회지
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• 제25권3호
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• pp.419-428
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• 2011

Recycling as a stabilizer of industrial by-product can be terms of the proper handling of industrial by-product and positive side in terms of recycling of waste. This study was performed to evaluate has the possibility as stabilizer by primary processing Pre-Red Mud and Bio-Solids which are generated as waste in soils contaminated with heavy metals and compared the efficiency with steel slug being applied in an existing site. In evaluation of the arsenic-fixing ability of stabilizer in batch test, Bio-Solids have the similar arsenic-fixing ability with Pre-Red Mud, which shows 17% h igher arsenic-fixing ability than PS Ball. Since the stabilization periods using Bio-Solids and Pre-Red Mud are faster than the PS Ball, they seems to be better stabilizer than PS Ball to decrease the leaching of arsenic in contaiminated soil.

• 지식경영연구
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• 제17권2호
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• pp.27-50
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• 2016

Korean manufacturing industry have recently faced the catch-up of China in the mass commodity product, such as automotive, display, and smart phone in terms of market as well as technology. Accordingly, discussion on the importance of achieving catch-up in complex product systems (CoPS) has been increasing as a new innovation engine for the industry. In order to achieve successful catch-up of CoPS, we explored emerging technologies of CoPS, which are featured by the characteristics of radical novelty, relatively fast growth and self-sustaining, through the study of emerging technologies of gas turbine for power generation. We found that emerging technologies of the gas turbine are technologies for combustion nozzle and composition of electrical machine for increasing power efficiency, washing technology for particulate matter, cast and material processing technology for enhancing durability from fatigue, cooling technologies from extremely high temperature, interconnection operation technology between renewable energy and the gas turbine for flexibility in power generation, and big data technology for remote monitoring and diagnosis of the gas turbine. We also found that those emerging technologies resulted in technological progress of the gas turbine by converging with other conventional technologies in the gas turbine. It indicates that emerging technologies in CoPS can be appeared on various technological knowledge fields and have complementary relationship with conventional technologies for technology progress of CoPS. It also implies that latecomers need to pursue integrated learning that includes emerging technologies as well as conventional technologies rather than independent learning related to emerging technologies for successful catch-up of CoPS. Our findings provide an important initial theoretical ground for investigating the emerging technologies and their characteristics in CoPS as well as recognizing knowledge management strategy for successful catch-up of latecomers. Our findings also contribute to the policy development of the CoPS from the perspective of innovation strategy and knowledge management.

• KSBB Journal
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• 제15권5호
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• pp.514-520
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• 2000

Simultaneous nitrification and denitrification of ammonia and organic compounds-containing wastewater were performed in a fluidized bed biofilm reactor with polysulfone(PS) hollow fiber as a double layer biomass carrier. The PS hollow fiber fragment has both aerobic and anoxic environments for the nitrifiaction and denitrification at the shell and lumen-side respectively. The reactor system showed about 80% nitrification efficiency stably throughout the ammonia load conditions applied in the experiment. Denitrification efficiency depended on organic load and C/N ratio. High free ammonia concentration and low dissolved oxygen resulted in nitrite accumulation which leads to enhance organic carbon efficiency in denitrification when compared to nitrate denitrification. The simultaneous nitrification and denitrification reactor system has an economic advantages in reduced chemical cost of organic carbon for denitrification as well as compact reactor configuration.

• Journal of Mechanical Science and Technology
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• 제16권10호
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• pp.1336-1345
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• 2002

A triboelectrostatic separation system using a fluidized bed tribocharger for the removal of PVC material in the mixture of PVC/PS plastics is designed and evaluated as a function of electric field strength, air flow rate, and the mixing ratio of two-component mixed plastics. It consists of a fluidized-bed tribocharger, a separation chamber, a collection chamber and a controller. PVC and PS particles can be imparted negative and positive surface charges, respectively, due to the difference in the work function values of plastics suspended in the fluidized-bed tribocharger, and can be separated by passing them through an external electric field. Experimental results show that separation efficiency is strongly dependent on the electric Deld strength and particle mixing ratio. In the optimum conditions of 150 Ipm air flow rate and 2.6 kV/cm electric field strength a highly concentrated PVC (99.1%) can be recovered with a yield of more than 99.2% from the mixture of PVC and PS materials for a single stage of processing.

• 한국안전학회지
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• 제27권4호
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• pp.50-61
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• 2012

In recent years, various research and developments to introduce composite bridges of new concept have been performed. The types of integral bridge and portal rigid frame bridge are having advantages in bridge maintenance and structural efficiency by eliminating expansion joints and bridge supports. However, the detail of typical girder-abutment connection has problems such as complexity of construction and increase of the construction cost. A new type of bridge, called prestress integral composite girder(PIC girder) bridge, is proposed in this study, which decreases the cost of construction and improves the efficiency of construction by simplifying the detail of construction for girder-abutment connection. PIC girder bridge has the connection detail in which the steel girder and the abutment are integrated by using the PS bar installed in the connection. In this study, finite element analysis and mock-up load test are conducted to evaluate the propriety of design, the effective of fabrication and structural safety for PIC girder bridge. The adequacy of the PIC giredr bridge is verified by the results of static/dynamic load test and finite element analyses.

• 정신신체의학
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• 제10권1호
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• pp.37-47
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• 2002

연구목적 : 수면관련 호흡장애 (sleep-related breathing disorder, SRBD)는 생명을 위협하는 중요한 질환으로 유병율이 매우 높다. 본 연구의 목적은 일차성 코골이 (PS) 환자와 폐쇄성 수면무호흡증 (OSA) 환자들이 보이는 정신의학적 증상들을 조사하는데 있다. 방법 : 동아대학교병원 수연장애 클리닉에 내원, SRBD가 의심되어 수면다원검사를 시행한 환자 중, SRBD로 확진받은 80명 (PS 29명 OSA 51 명)을 연구대상으로 하였다. 다면적 인성검사 (MMPI)와 간이정신진단검사 (SCL-90-R)를 실시하여 PS군과 OSA군의 정신의학적 증상들을 조사 분석하였다. 결과 : 전체 SRBD 환자군은 MMPI의 건강염려증(Hs), 우울증(D), 히스테리(Hy) 척도와 SCL-90-R의 선체화(SOM) 척도의 증가율이 타 척도보다 더 높았다. 이런 현상은 PS와 OSA로 구분하였을 때도 두군 모두에서 3가지 신경증 척도들의 증가율이 높았다 두군간의 비교에서, SCL-90-R의 강박증 (O-C, t=2.14), 우울증 (DEP, t=2.44), 편집증 (PAR, t=2.56), 전체 심도지수 (GSI, t=2.32) 척도(이상 p<0.05) 및 신체화(SOM, t=2.46), 표출 증상합계 (PST, t=2.75) 척도(이상 p<0.01)의 평균점수, 그리고 MMPI의 건강염려증(Hs, t=3.39) 척도와 SCL-90-R 신체화 (SOM, t=6.52) 척도의 증가율이 PS군보다 OSA군에서 유의하게 높았다(모두 p<0.05). 반응 척도와 수면 변인들 간의 상관관계 조사에서, 몇몇 심리 반응 척도들 즉, OSA군의 MMPI(D, Pt, Si) 및 SCL-90-R(ANX, PAR, PSDI) 척도와 PS군의 MMPI(Hy, Pt, Si) 및 SCL-90-R(I-S, PAR. PSDI) 척도, 그리고 PS군의 MMPI 척도 증가율(E')이 수면효율과 서파수면시간 등의 다양한 수면변인들과 상관관계를 보였다. 결론 : 본 연구의 결과는 SRBD 환자들이 신체화 경향을 주로 하는 신경증적 특정을 보이고 있음을 시사한다. 또한 비록 OSA군이 PS군에 비하여 정신의학적 증상을 더 심하게 호소하고 있지만, PS군도 일반인구보다 정신의학적 증상을 더 많이 호소하고 있었다. 이 결과는 OSA군뿐만 아니라 PS군에 대한 정신의학적 관심이 필요함을 시사한다.

• 한국통신학회논문지
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• 제38B권8호
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• pp.679-686
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• 2013

데이터전송 증가에 따라 제한적인 배터리를 사용하는 모바일 단말에서 효율적으로 전력을 사용하는 것은 중요하게 여겨지고 있다. 802.11 표준에 있는 Power Saving Mechanism (PSM)은 부하가 많은 네트워크에서 적합하지 않다. AP(Access Point)는 버퍼링된 프레임을 PS (Power Saving) 단말들에게 즉시 보낼 수 없어서 단말들이 깨어 있는 모드를 계속 유지함으로써 전력을 낭비하게 된다. 또한, PS단말들이 하나의 데이터 프레임을 받기 위해 AP에게 하나의 PS-POLL프레임을 전송하는 방식은 효율적이지 않다. 본 논문에서는 802.11 PSM의 성능을 향상하기 위해 PS단말들이 AP에게 데이터 받을 시간을 미리 예약하는 시분할 메커니즘을 제안한다. 제안된 메커니즘은 충돌가능성을 감소시킬 수 있으며 채널사용 효율을 높일 수 있다. 분석결과 및 시뮬레이션 결과로부터, 제안된 시분할 메커니즘은 전체 네트워크의 전력소비가 효과적으로 감소되며, PSM의 성능을 개선시킨다.

• 폴리머
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• 제26권1호
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• pp.71-79
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• 2002

RPP(maleic-anhydride grafted polypropylene)와 OPS(oxazoline grafted polystyrene) 블렌드는 비혼화성으로서 반응이 일어나지 않으므로 RPP와 OPS에 Nylon6를 반응상용화제로 첨가하였다. RPP, Nylons, OPS간의 반응을 반응토오크, FT-IR, DSC로 관찰하였다. 3성분계 반응의 결과물로 반응상용화제인 RPP/Nylon6/OPS가 생성됨을 확인하였다. RPP/Nylon6/OPS의 반응은 RPP와 OPS가 1:1일 때 Nylons의 당량비가 0.66에서 최대 반응토오크를 얻었으며, Nylon6의 당량비가 1일 때 반응 효율이 크게 나타났다. RPP/Nylon6/OPS의 반응에 따른 몰폴로지의 변화를 관찰하여 반응정도가 높을수록 미세한 균일상을 얻었다. 블렌드의 물성은 Nylon6의 당량비가 1.5일 때 가장 높은 물성값을 얻었다. 만들어진 RPP/Nylon6/OPS 3성분계 블렌드를 PP/PS 단순 블렌드에 첨가하여 상용성을 고찰하였고 PP/Nylon6/PS 비혼화성 블렌드와 비교분석 하였다. 결과적으로 RPP/Nylon6/OPS가 PP와 PS 블렌드계의 반응상용화제로 적절함을 확인하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.744-747
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• 2005

The exploitable efficiency of UHP is very important in a projection system. We always use lens array for light shaping and energy distribution transformation in conventional projection system. Because of the limitation of arc gap and F/# of elements, the utilize efficiency is always dismal. In this paper we try to bring out a new method to reduce the sparkle formed on the PS converter and enhance the system efficiency.