• 한국주조공학회지
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• 제30권6호
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• pp.210-216
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• 2010

The aim of this study is to characterize a thixoextruded 7075 Al wrought alloy bar in terms of its isotropic behavior through the optical microscope, mechanical test and electron back scattered diffraction. It is also discussed of the extrudability improvement for 7075 Al wrought alloy by thixoextrusion, with emphasis on controlling thixoextrusion parameters. Hot extrusion shows that the maximum extrusion pressure depends on their characteristics in terms of flow stress and hot workability. In the contrary, thixoextrusion demonstrates that the maximum extrusion pressure is almost uniform regardless of the experimental parameters, such as initial ram speed, die bearing length and thixoextrusion temperature. The hot extruded microstructures become elongated to extrusion direction, while the thixoextruded microstructures are isotropic and homogeneously distributed due to the existence of liquid phase between solid grains during the process. The grain refinement due to dynamic recrystallization during thixoextrusion has been also occurred. Subsequent recrystallization would lead to the strengthening of mechanical properties, as observed in the study. The important point is that the values of tensile, yield strength and elongation of the thixoextruded bar without plastic deformation are similar to those of the hot extruded bar with severe plastic deformation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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• pp.27-30
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• 2006

In this paper, the undoped and Co-doped $Zn_4SnSe_6$ single crystals grown by the chemical transporting reaction(CTR) method using iodine as a transporting agent are investigated. For the crystal growth, the temperature gradient of the CTR furnace was kept at $680^{\circ}C$ for the source zone and at $780^{\circ}C$ for the growth zone for 7days. It was found from the analysis of x-ray diffraction that the $Zn_4SnSe_6$ and $Zn_4SnSe_6Co^{2+}$ compounds have a monoclinic structure. The direct optical energy band gap of the $Zn_4SnSe_6$ and $Zn_4SnSe_6Co^{2+}$ single crystals at 300K were found to be 2.146eV and 2.042eV.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.66-70
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• 1999

영국의 정보통신기술기준체제는 다양한 형태의 운영양상을 띠고 있다. 이는 크게 유럽지침에 의거 직접적으로 입법화를 하는 경우 (Direct Legislation by EU Directive) 유럽공통기술기준(CTR:Common Technology Regulations)을 사용하는 경우, 영국 국가기술기준 (NTR: National Technology Requirement)를 사용하는 경우, 기본통신법의 후속조치인 시행령(order) 및 시행규칙(Regulation)을 사용하는 경우로 나누어볼 수 있다. 이러한 영국의 정보통신 기술기준 운영체제의 특징을 정리해보면 다음과 같다. 첫째 영국은 기본적으로는 유럽연합의 공통기술기준(CTR) 운영체제를 수용하면서도 별도의 국가기술기준(NTR)을 제정 단말장치분야와 같은 망 간 접속에서 규격의 통일화 및 호환성 확보에 보다 중점을 두고 있다는 점이다 둘째, 영국에서의 기술기준의 적용유형은 상당히 복잡하면서도 고도로 체계화되어 있다는 점이다. 셋째, 영국은 BSI 표준 및 BABT의 SITS 등을 통합하여 국가적 차원의 강제규범화 사업자 표준을 국가적 규범의 틀로 흡수하고 있다는 점이다.

• 한국주조공학회지
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• 제25권6호
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• pp.254-258
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• 2005

Semisolid process is possible in any material system possessing a freezing range where the microstructure should consist of the nondendritic globular solid phase separated and enclosed by the liquid phase, referred to as semisolid slurry. There are two primary semisolid processing routes, thixocasting and rheocasting. Especially, rheocasting process has become a new focus in the field of semisolid process because of its many advantages such as no special billet required and possibility of in-house scrap recycling, compared with the thixocasting process. In-Ladle direct thermal control (DTC) rheocasting has been developed, based on the fact that there is slurry and mush transition in every molten metal and the transition, which normally occurs in the range of liquid traction of 0.1 to 0.6, could be controlled by controlling solid shape and relative solid-liquid interfacial energy. In this study, A356 Al alloy was investigated to verify In-Ladle DTC rheocasting for obtaining semisolid slurry. Modeling of heat transfer was carried out to investigate the effect of pouring temperature and ladle material, geometry and temperature and the simulation results were compared with the actual experiments.

• 정보보호학회논문지
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• 제17권1호
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• pp.103-107
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• 2007

본 논문에서는 JCCI 2003에 제안된 새로운 인증-암호화 모드 $NAE^{[1]}$에 대한 위조 공격을 제안한다. NAE는 CFB 모드와 CTR 모드를 결합시킨 변형된 형태로, 하나의 기반이 되는 블록암호 키를 가지고 최소한으로 블록암호를 호출하는 인증-암호화 기법이다. 그러나 본 논문에서는 단순 암호문 조작으로 NAE에 대해 유효한 암호문-태그 쌍을 생성할 수 있음을 보인다.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2633-2640
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• 2024

The purpose of this study was to investigate the effect of the reflector, surface treatment, and length of scintillation crystals on the performance of a time-of-flight and depth-of-interaction (TOF-DOI) PET detector with a dual-ended readout and to determine the best reflector and surface treatment. Various types of crystal arrays with three different reflectors (ESR, BaSO₄, and Toray), three different lateral surface treatments (all-polished (AP), all-roughened (AR), and partially roughened (PR, three sides polished, and one side roughened)), and two different lengths (20 and 15 mm) were fabricated. The highest light collection efficiency and best energy resolution were achieved using a crystal with a diffuse reflector (BaSO₄ for AP and Toray for AR). In contrast, the best coincidence timing resolution (CTR) was achieved using an AR crystal with a specular reflector (ESR). The best DOI resolution was achieved using an AR crystal with BaSO₄. Moreover, the results measured with the 20 mm long crystals were similar to those measured with the 15 mm long crystals. Therefore, we concluded that the dual-ended readout PET detector employing the crystal with AR lateral surface treatment and ESR was a good candidate for TOF-DOI PET because it provided excellent CTR and adequate DOI resolution.

• 경영정보학연구
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• 제26권2호
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• pp.123-136
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• 2024

날씨는 우리 일상에 깊은 영향을 주는 요소로 소비자의 심리와 행동에 영향을 미치기 때문에 날씨의 변화는 소비자의 광고 수용 행태에도 영향을 미치고 기업의 매출에 직접적인 영향을 준다. 이에 따라, 기업들은 마케팅 및 홍보에 있어 전략적으로 날씨를 활용해 왔으며 중요하게 관리해야 하는 요소로 인식해왔다. 모바일 디바이스의 등장에 따라 사용자가 접하는 광고 매체와 지면은 그 이전보다 기하급수적으로 증가하였다. 모바일 환경의 경우 자는 시간을 제외하고는 실시간으로 접속하기 때문에 광고에 노출되는 시간과 밀도도 증가하였다. 날씨가 사용자의 모바일 광고 수용행태에 어떻게 영향을 주는지를 실증적으로 확인하는 것은 상당히 중요하지만, 이와 관련된 연구가 부재하다. 따라서 본 연구는 날씨가 모바일 광고 수용행태에 끼치는 영향을 실증적으로 확인하였으며, 환경변화에 따라 영향이 증가하는 대기질에 대해서도 함께 고려하였다. 본 연구의 결과는 디지털 광고 플랫폼 사업자나 광고 주체에게 날씨 정보를 활용한 타겟팅 전략의 개선에 도움이 될 것으로 기대한다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권11호
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• pp.1773-1780
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• 2018

Objective: This study was to evaluate effects of mixed plant oils (identified as mixed oil 1 [MO1] and mixed oil 2 [MO2]) on performance, serum composition, viscera percentages, meat quality, and fatty acid deposition of broilers. Methods: A total of 126 one-day-old Arbor Acres male broiler chicks (weighing $44.91{\pm}0.92g$) were randomly allocated to 1 of 3 treatments with 7 replicate pens per treatment (6 broilers per pen). Dietary treatments included a corn-soybean basal diet supplemented with 3% soybean oil (CTR), basal diet with 3% MO1 (a mixture of 15% corn oil, 10% coconut oil, 15% linseed oil, 20% palm oil, 15% peanut oil and 25% soybean oil; MO1), or basal diet with 3% MO2 (a combination of 50% MO1 and 50% extruded corn; MO2). The trial consisted of phase 1 (d 1 to 21) and phase 2 (d 22 to 42). Results: Compared to CTR, broilers fed MO (MO1 or MO2) had greater (p<0.05) average daily gain in phase 1, 2, and overall (d 1 to 42), redness in thigh muscle, concentrations of serum glucose, serum albumin, saturated fatty acids (SFA) and n-6/n-3 polyunsaturated fatty acids (PUFA) ratio in breast muscle, while these broilers also showed lower ($p{\leq}0.05$) drip loss and concentrations of C18:3n-3 and PUFA/SFA ratio in breast muscle. Broilers fed MO2 had higher (p<0.05) liver percentage, while broilers fed MO1 had lower ($p{\leq}0.05$) feed conversion ratio in phase 1 and increased (p<0.05) contents of C18:2n-6, C20:5n-3, C22:6n-3, and n-3 PUFA in breast muscle compared to CTR. Conclusion: Mixed plant oils had positive effects on performance, serum parameters, meat quality, liver percentage and fatty acid deposition in broilers, which indicates they can be used as better dietary energy feedstocks than soybean oil alone.

• 대한디지털의료영상학회논문지
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• 제12권2호
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• pp.119-125
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• 2010

In order to demonstrate the value of long-distance radiography, we have studied how distance affects images in chest frontal radiography and compared short-distance and long-distance images in chest lateral radiography. Cardiothoracic ratio(CTR %) of 50 patients with no disease in the chest(10 each at the age of 20~60) were evaluated in Supine AP(100 cm), Sitting AP(100 cm), Sitting AP(180 cm), and Erect PA(180 cm). In lateral radiography, we evaluated and compared left lateral radiography(100 cm and 180 cm) of the patients based on the horizontal maximum of the heart. The average value of CTR(%) were 0.48 in Erect PA(180 cm), 0.52 in Supine AP(100 cm), 0.50 in Sitting AP(100 cm), 0.49 in Sitting AP(180 cm), which were Supine AP(100 cm) > Sitting AP(100 cm) > Sitting AP(180 cm) > Erect PA(180 cm). The average value of Maximum transverse diameter of left of the cardiac(MLD), which showed how much axis of spine was slanted to the left, was 90.67 mm in Erect PA(180 cm), 103.92 mm in Supine AP(100 cm), 93.54 mm in Sitting(100 cm), 89.84 mm in Sitting AP(180 cm), 58.11 mm in the minimum value and 118.79 mm in the maximum value. The average value of Maximum transverse diameter of right side of the cardiac(MRD), which suggested how much axis of spine was slanted to the right, was 47.18 mm in Erect PA(180 cm), 48.12 mm in Supine AP(100 cm), 44.98 mm in Sitting AP(180 cm), and the minimum value 26.84 mm and the maximum value 65.30 mm. There was no standard method to calculate; therefore, the horizontal maximum of the heart was used for lateral radiography. The average value was 121.07 mm in 100 cm and 109.76 mm in 180 cm. Sitting AP(180 cm) among the types was closest to C-PA(180 cm). As a result, during C-AP radiography, long-distance radiography lessened shadow of the heart more than that of short distance, Sitting position more than Supine position.

• 대한한의학회지
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• 제31권2호
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• pp.91-108
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• 2010

Background & Objective: The aim of this study was to investigate the effect of P. radix on the inflammatory related gene expression in IL-$1{\beta}$-stimulated primary human gingival fibroblast using Whole Transcript Sense Target (WT-ST). Method: Human gingival fibroblast was incubated with P. radix [100 or $200\;{\mu}g/ml$], and IL-$1{\beta}$ [$1ng/m{\ell}$] added an hour later. After 24h, total RNA was extracted using RNeasy Mini Kit and the whole gene expression patterns were performed using WT-ST Labeling $Assay^{(R)}$. Result: In the DEG results, 782 genes were up-regulated in the IL-$1{\beta}$-treated group as compared to control and among those, 43 genes were associated with inflammation. 981 genes were down-regulated after treatment with IL-$1{\beta}$ and of those 7 genes were associated with inflammation. 1439 genes were up-regulated after treatment with P. radix plus IL-$1{\beta}$-treated when compared to IL-$1{\beta}$-treated alone group and 1225 genes were down-regulated in the same condition. Among the down-regulated genes, 5 were associated with inflammation- and inhibitor genes such as GDF15 and LIF. In the analysis of the P. radix plus IL-$1{\beta}$-treated group, the most significant pathways were the cytokine-cytokine receptor interaction, toll-like receptor signaling, JAK-STAT signaling and tyrosine metabolism. The gene expression patterns in the P. radix $200{\mu}g/m{\ell}$ plus IL-$1{\beta}$-treated group appear to be more involved in the metabolism-related pathways than in the $100{\mu}g/m{\ell}$ plus IL-$1{\beta}$-treated group. Conclusion & Discussion: By microarray analysis of gene expression data, we are able to identify gene expression patterns associated with not only anti-inflammation effect but also transcription function of P. radix.