• Proceedings of the Korean Society for Information Management Conference
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• 2003.08a
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• pp.65-72
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• 2003

kNN 기법은 높은 자동분류 성능을 보여주지만 처리 속도가 느리다는 단점이 있다. 이를 극복하기 위해 입력문서의 대표용어 w개를 선정하고 이를 포함한 학습문서만으로 학습집단을 축소함으로써 자동분류 속도를 향상시키는 kw_kNN을 제안하였다. 실험 결과 대표 용어를 5개 사용할 경우에는 kNN 대비 문서간 비교횟수를 평균 18.4%로 축소할 수 있었다. 그러면서도 성능저하를 최소화하여 매크로 평균 F1 척도면에서는 차이가 없고 마이크로 평균정확률 면에서는 약 l∼2% 포인트 이내로 kNN 기법의 성능에 근접한 결과를 얻었다.

• Annual Conference of KIPS
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• 2003.05c
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• pp.1669-1672
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• 2003

오늘날 컴퓨터와 인터넷의 빠른 보급과 발전으로 인해 게임은 급속도로 확산 보급되어왔다. 종합예술이라고 불릴 만큼 다양한 기술이 뒷받침되어 게임 산업은 21세기의 고부가가치 산업으로 각광을 받고 있으며 새로운 게임의 종류와 장르가 다양해졌다. 그 중 온라인게임은 산업적인 면과 정부지원이란 면에서 주요한 산업으로 부상하고 있다. 본 논문에서는 온라인게임 소프트웨어 품질 향상을 위한 테스트의 요소들을 파악하고 품질평가 요소로 제안한 후 개발 단계에서의 적용 시점을 제안하고자 한다.

• Annual Conference of KIPS
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• 2010.11a
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• pp.1395-1398
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• 2010

최근 GWAS(Genome-wide association study)로 인해 수십만 개의 SNP들이 사용 가능하게 되었다. 그러나 SNP 정보의 양이 방대하여 모든 SNP 조합을 검토하는 방식은 계산 비용이 클 뿐 아니라 오버피팅의 위험이 따른다. 본 논문에서는 필터링 기반 알고리즘인 SNPHarvester의 속도를 개선하고 평가함수를 상호정보량으로 대체하여 실험한다. 기존 SNPHarvester와 비교해 속도면에서 50%가 향상되었고 평가함수 면에서는 기존 SNPHarvester와 동일한 성능을 보였다.

• Journal of the Korean earth science society
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• v.32 no.7
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• pp.809-831
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• 2011

Sea Surface Temperature (SST) is one of the most important oceanic variables to understand rapidly-changing climate, so that accurate and error-free SST images should be presented in school science textbooks. However, satelliteobserved SST images in the high-school textbooks presented some errors caused by various reasons. This study analyzed 36 satellite images for SST presented in 24 kinds of high-school textbooks (earth science I and II textbooks on the basis of the 7th National Curriculum) for 17 items. This study investigated errors in image processing such as cloud removal, land masking, color bar, geological and time information, and some erroneous expressions related to the fundamental information of satellites. Twenty five pre-service teachers filled out a survey about several problematic satellite images, and their responses were analyzed. As a result, most of the pre-service teachers did not recognize the errors associated with image processing and tended to comprehend the SST errors as real oceanographic phenomena such as sea ice, river outflow, or cold current. Therefore, satellite SST images in the textbooks should be accurately presented by including detailed items suggested in this study.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.850-856
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• 2013

This study was conducted to determine the effects of physical treatments for quality of wet noodles. Noodles were being tried with a microwave (for 1 min), an autoclave (for 30 or 50 min), and both autoclave and microwave (for 30/1 min or 50/1 min). The results showed that the pH levels were slightly decreased after treatments of autoclave and autoclave/microwave. The moisture contents were considerably decreased as compared to the control except autoclave (50 min). After all treatments, the lightness was decreased in all samples, but, redness was increased (except microwave) and the yellowness was increased after autoclave (50 min) and autoclave/microwave (50/1 min). Texture was increased as compared to the control except microwave. In the sensory evaluation, the noodles treated with microwave, autoclave (50 min), and autoclave/ microwave (50/1 min) showed a high score in overall preference. From these results, both the autoclave and microwave methods can be applied to the wet noodles without diminishing its quality to a great extent.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.629-634
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• 1995

Zr-2.5 % Nb 합금 압력관에서 집합조직이 강도에 미치는 영향을 조사하여 기저면 성분(F)의 강화 효과를 분리하였으며 아울러 온도에 따른 강도의 변화를 조사하였다. As-received 압력관 재료의 상온 항복 강도는 인장 응력에 수직한 면에서 측정한 기저면 성분(F)에 대하여 $\sigma$$_{YS}$ =600 + 410 F 의 관계를, annealing 처리한 등축정 재료의 상온 항복 강도는 $\sigma$$_{YS}$ = 410 +310 F 의 관계를 따르는 것으로 나타나 기저면 성분이 주도적인 강화 효과를 갖는다는 것을 확인 할 수 있다. 따라서 Zr 합금의 항복 강도는 인장 응력에 수직한 면에서의 기저면 성분에 따라 좌우되며, Zr-2.5% Nb 압력관에서 길이 및 원주 방향에서의 항복 강도의 차이는 주로 기저면 성분의 차이 (F)에 의한 것이라고 결론지을 수 있다. $\alpha$-Zr 에서 슬립과 쌍정의 임계 전단 응력 및온도에 따른 변형 기구의 변화에 대하여 논의하였다.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.73-83
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• 1993

The purpose of this study was to evaluate the effect of various acid treatments on dentin bonding. Freshly extracted human teeth were uprightly embedded in self curing acrylic resin, and their occlusal surfaces were grinded to expose flat dentin surfaces. The specimens were divided into 4 groups. Specimens of one group were not treated so as to be a control and those of the other three groups were threated with 10% polyacrylic acid, 10% phosphoric acid, and 10-3 solution(10% citric acid/3% ferric chloride) respectively. Primer, bonding resin and composite resin were applied over the treated dentin surfaces sequentially. All specimens were stored in $37^{\circ}C$ distilled water for 24 hours, then the tensile bond strength was measured and the treated dentin surfaces and fracured dentin surfaces were examined under a scanning electron microscope. The results were as follows: Bond strengths of acid-treated groups were higher than those of the untreated group. In the acid-treated groups, bond strength was found to be the highest in the 10-3 solution group followed by the 10% phosphoric acid group and the 10% polyacrylic acid group(P<0.01). On SEM examination of dentin surfaces, the untreated dentin surface showed a remaining smear layer and closed dentinal tubules. Dentin surfaces treated with 10 % polyacrylic acid showed a clean dentin surface without the smear layer, but showed remaining smear plugs in dentinal tubules. A dentin surface treated with 10% phosphoric acid or 10-3 solution showed open dentinal tubules without the smear layer or smear plugs. On SEM observation of the fractured dentin-resin interface, the untreated group showed that failure occurred in the smear layer. The group treated with 10% polyacrylic acid showed no resin tag remained in the dentinal tubules, but resin tags in the dentinal tubules were observed in the group treated with the 10% phosphoric acid or the 10-3 solution. On the failure mode examination, the higher the bond strength of the group, the higher the frequency of cohesive failure. The coefficient between bond strength and cohesive failure rate was 0.71.

• Geophysics and Geophysical Exploration
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• v.23 no.3
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• pp.168-177
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• 2020

Seabed multiple reflections (seabed multiples) are the main cause of misinterpretations of primary reflections in both shot gathers and stack sections. Accordingly, seabed multiples need to be suppressed throughout data processing. Conventional model-driven methods, such as prediction-error deconvolution, Radon filtering, and data-driven methods, such as the surface-related multiple elimination technique, have been used to attenuate multiple reflections. However, the vast majority of processing workflows require time-consuming steps when testing and selecting the processing parameters in addition to computational power and skilled data-processing techniques. To attenuate seabed multiples in seismic reflection data, input gathers with seabed multiples and label gathers without seabed multiples were generated via numerical modeling using the Marmousi2 velocity structure. The training data consisted of normal-moveout-corrected common midpoint gathers fed into a U-Net neural network. The well-trained model was found to effectively attenuate the seabed multiples according to the image similarity between the prediction result and the target data, and demonstrated good applicability to field data.

• Journal of the Korea Concrete Institute
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• v.28 no.6
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• pp.637-646
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• 2016

In this study, slant shear tests for the prism specimens strengthened with ultra-high performance fiber reinforced concrete (UHPFRC), normal- and high-strength concrete were performed to evaluate the interfacial shear strength between old and new concrete substrate. Test parameters are the roughness of surface, concrete strength, and fiber volume fraction of UHPFRC. The surface of the concrete was roughened by shot blasting. Test results showed that the adhesion bond resistance of the specimen with a roughened surface was very large compared to that of the specimen with a smooth surface. In addition, the interfacial shear strength appeared to be affected by the concrete strength rather than the fiber volume fraction. For the roughened surface by shot-blasting method, interfacial shear resistance exceeded the upper limit which is presented in current design codes even if the shear-friction reinforcements are not provided. Based on the test results, it is applicable to use the current concrete design codes to achieve the shear-friction design for the interface between conventional concrete and UHPFRC. However, for the surface which is not processed, it would be appropriate to provide additional shear-friction reinforcement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.161-166
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• 2020

In accordance with the amendment of the Industrial Safety and Health Act of 2007, Korea completely prohibited the import, distribution and manufacture of asbestos like Europe and Japan. Accordingly, the current problem of asbestos is the safe maintenance and disposal of asbestos construction material, the disposal of asbestos, and the final disposal of asbestos building materials. If the asbestos building material is made harmless, it may be classified as general waste or as recyclable waste. Therefore, this study evaluated the physical and chemical characterization of detoxified asbestos powder and the applicability of secondary products. In this study, it was found that applying the appropriate temperature and pressure for catalysis during asbestos desalination through low temperature chemical treatment was the most important factor.