• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.104-111
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• 2006

The non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by material tests which are uni-axial tension and bi-axial tension. The computer simulation using the nonlinear element analysis program executed to predict and evaluate the load capacity and stiffness for chevron spring. In order to investigate the heat-aging effects on the rubber material properties, the acceleration test were carried out. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the compression set test, several useful life prediction for rubber material were proposed.

• 한국기계연구소 소보
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• 통권13호
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• pp.27-43
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• 1984

In order to obtain the high resilience, low compression set and less of hardness change in the wiper blade rubber, vulcanization system and receipes must be controlled. To improve the above the above Physical properties, the system should be taken as follows. i) peroxide vulcanization system and sulfur vulcanization system. ii) rubber having more cis-form than trans-form. iii) moderate particle size cabon black. v) usage of other improvement agent. The rubber blade with 4.4% compression set, 76% resilience, Hs 0 $\pm$ 2 hardness change could be abtained through vulcanization system, In addition, the surface of wiper blade must be treated by chemically and physically to minimize for the skid and friction.

• 한국의류학회지
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• 제36권8호
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• pp.860-874
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• 2012

This study provides size information on current imported medical compression stockings in Korea. A total 20 brands from 6 countries imported and sold in the Korean on-off line markets were selected for this study and the sizing system of medical compression stockings was researched. The results of this study were as follows: there were size differences among different USA brands according to product type or compression class of medical compression stockings. To establish the sizing system for medical stockings of the German brands, the basic body measurements standard was set as cA, cY, cB, cB, cC, cD, cE, cF, cG, cH, cT, lD, lG, and lT. Italian brands developed the sizing system for medical compression stockings by compression class. In the Swiss brands, size types were sub-divided as 'Normal', 'Plus', 'Short', and 'Long'. The sizing 1 were confined within very narrow limits. There were differences of the basic body measurements between Taiwan brands. The results of the comparison of the size range of the imported brands with Size Korea (KATS, 2010) by two-way size distribution shows that the sizing systems of the imported brands were unsuitable for Koreans. To enhance the suitability of the sizing system for medical compression stockings, a new sizing system for Korean adult males and females needs to be established.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.609-612
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• 1999

In this paper, we propose wavelet transform image compression method such that an image is decomposed into multiresolutions using biorthogonal wavelet transform with linear phase response property and decomposed subbands are classified by maximum classification gain. The classified data is quantized by allocating bits in accordance with classified class informations within subbands through arbitrary set bit allocation algorithm. And then, quantized data in each subband are entropy coded. The proposed coding method is that the quantized data perform shuffling before entropy coding in order to remove sign bit plane. And the context is assigned by maximum correlation direction for bit plane coding.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.470-478
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• 2007

The purpose of this study was to investigate the clinical, biomechanical, and histologic changes in new distraction osteogenesis(DO) technique combined with a compression stimulation in accordance to different compression-distraction force ratio. 23 adult male rabbits underwent open-osteotomy at the mandibular body area and a external distraction device was applied. In the control group of 8 rabbits, only a 8 mm of distraction was performed by conventional DO technique. In an experimental group of 15 rabbits, a distraction followed by a compression force was performed according to the ratio of compression-distraction suggested by authors. The rate of experimental group I was set up as a 2 mm compression versus 10 mm distraction and the rate of experimental group II was set up as a 3 mm compression versus 11 mm distraction. All the rabbits were sacrificed for a gross finding, biomechanical, histomorphometric and histologic findings at the time of 55 days from the operation day. The results were as follows: 1. On the gross findings, because all rabbits had a sufficient healing time, every distracted new bone had good bone quality and we could not find any difference among all three groups. 2. In the histologic findings, rapid bone maturation(wide lamellar bone formation in the cancellous and cortical bone areas) was observed in two experimental groups compared to the control group. 3. On the bone density tests, the experimental group II showed higher bone density than the other experimental group and control group(control group-$0,2906g/cm^2$, experimental group I-$0.2961g/cm^2$, experimental group II-$0.3328g/cm^2$). 4. On the biomechanical tests, the experimental group II had significantly higher bone microhardness than the other experimental group and control group(control group-252.7 MPa, experimental group I-263.5 MPa, experimental group II-426.0 MPa). 5. On the microhardness tests, when we compared the hardness ratio of distracted bone versus normal bone, we could find experimental group II had significantly higher hardness ratio than the other experimental group and control group(control group-0.47, experimental group I-0.575, experimental group II-0.80). From this study, we could deduce that the modified distraction osteogenesis method with a compression stimulation might improve the quality of bone regeneration and shorten the consolidation period in comparison with conventional distraction osteogenesis techniques.

• 방송공학회논문지
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• 제6권1호
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• pp.98-107
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• 2001

본 논문은 한글 텍스트 데이터에 대한 부호화 효율을 극대화시키는 관점에서 예외 부호화를 통해 최적의 허프만 부호를 얻는 다. 한글 코드는 표준 완성형과 유니 코드를 대상으로 하였으며 같은 허프만 부호를 부여하였다. 현재 우리나라의 디지털 TV는 한글 문자를 압축하지 않고 전송하는 형태이며. 본격적인 데이터 방송이 시작되면 한글 데이터가 차지하는 전송량으로 인한 심자 한 문제가 야기된다. 본 논문에서는 데이터 방송에서 문제가 되는 전송량을 줄이기 위해 한글 진용 퇴적의 허프만 부호를 생성한 다. 미국의 ATSC 표준을 바탕으로 한 디지털 TV 국내 표준에 적용하기 위해 프로그램 및 시스템 프로토콜(PSIP) 구조를 제안한 다. 결과로서. 발생확률 0.0043 이하의 확률을 갖는 문자를 예외 부호화하여 최대 47%의 압축율을 얻는 기법을 제안하였다.

• Journal of the Korean Wood Science and Technology
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• 제43권4호
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• pp.470-477
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• 2015

국내산 잣나무(Pinus koraiensis Sieb. et Zucc.) 열압밀화재의 치수안정성 확보를 위해 열압밀화 후 열처리를 실시하여 흡수시험을 실시하였다. 잣나무재를 압축세트량 50%로 열압밀화하여 비중 0.84의 고비중재를 얻을 수 있었다. 열처리 온도와 시간이 증가함에 따라 열압밀화재의 흡수성과 팽윤성은 감소하였다. 그리고 열압밀화 후 열처리에 의해 열압밀화재의 치수안정성은 크게 향상되었다. 대조군의 두께 회복률이 11.5%인 반면, $120^{\circ}C$ 온도에서 24시간 열처리 된 그룹의 두께회복도는 3.8%로 나타났다. 열압밀화 후 열처리는 열압밀화재의 치수안정성 확보를 위한 매우 효과적인 방안임을 확인하였다.

• 한국통신학회논문지
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• 제19권11호
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• pp.2264-2275
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• 1994

본 논문에서는 블록 분류와 코딩과 함께 신경회로망을 이용한 영상압축을 보였다. 오차 역전파 알고리즘으로 학습되는 다층구조 신경회로망은 정규화된 영상데이타를 감소된 공간 중복성을 가지는 은닉층의 값으로 변환하는데 사용된다. 기본적으로 영상압축은 입력층과 출력층의 뉴런보다 적은 수의 은닉층 뉴런에 의해 얻어진다. 여기에 시각체계의 민감도에 따른 영상블럭 복잡성에 따라 적응적으로 압축되므로 블록을 분류한다. 또한 은닉뉴런의 양자화된 값은 효과적인 전송을 위해 entropy coding을 이용한 경우 화질의 큰 저하없이 약 25:1의 압축률을 얻었다.

• Journal of Biosystems Engineering
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• 제21권1호
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• pp.52-59
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• 1996

In this study, the combined forces of electro-osmosis and compression were applied to cabbage dewatering and their effects were discussed. Nine treatments of combined forces consisting of three levels of voltage and compression were applied to chopped and macerated chinese cabbage placed in the experimental set-up consisted of cylinder-piston. The results showed that as both voltage and pressure increased the dewatering rates increased and the combined force of voltage and compression was a very effective means in the dewatering of chinese cabbage in which the largest dewatering rate difference, 72%, was found between the combined force of 30V with 68.2kPa and no voltage(0V) with 68.2kPa. However, no significant difference was found between the voltage of 0 and 10volts in 9.75kPa and the pressure of 68.2kP and 126.7kPa in 30volts. The maximum and minimum dewatering rate were 82% in the combined force of 30 volts of 126.7kPa and 8% in 0 volt of 9.75kPa, respectively. Within the experimental trials, it appeared that the best treatment combination would be pressure of 68.2kPa and voltage of 30V producing dewatering rate of 80ft in which the produced liquid contained about 1% solid. Employing this dewatering method as a pretreatment before drying process can contribute in considerable energy saving in agricultural wastes treatment.

• International Journal of Automotive Technology
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• 제7권6호
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• pp.675-680
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• 2006

In the direct injected gasoline engine, atomized spray is desired to achieve efficient mixture formation needed to good engine performance because the injection process leaves little time for the evaporation of fuels. Therefore, substantial understanding of global spray structure and quantitative characteristics of spray are decisive technology to optimize combustion system of a GDI engine. The combustion and emission characteristics of gasoline-fueled stratified-charge compression ignition(SCCI) engine according to intake temperature and compression ratio was examined. The fuel was injected directly to the cylinder under the high temperature condition resulting from heating the intake port. With this injection strategy, the SCCI combustion region was expanded dramatically without any increase in NOx emissions, which were seen in the case of compression stroke injection. Injection timing during the intake temperature was found to be an important parameter that affects the SCCI region width. The mixture stratification and the fuel reformation can be utilized to reduce the required intake temperature for suitable SCCI combustion under each set of engine speed and compression ratio conditions.