• 한국정밀공학회지
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• 제15권10호
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• pp.51-57
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• 1998

In this paper, a computer aided process design technique, utilizing a forging simulator and a commercial CAD software, is presented together with its related design system for cold-former forging of ball joints. The forging sequence design is carried out through user-computer interaction by using design templates, design database, experience or knowledge-based rules and some basic laws found in the literature. The forging simulation technique is used to verify the process design. The detail designs including die set drawings and die manufacturing information are automatically generated. It has been shown that the engineer ing and design productivity is much improved by the presented approach in the practical standpoint of process design engineers.

• 한국세라믹학회지
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• 제45권11호
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• pp.675-680
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• 2008

The effect of pore former content on both porosity and pore structure was investigated for porous sintered reaction-bonded silicon nitrides (SRBSNs). A spherical PMMA with $d_{50}=8{\mu}m$ was employed as a pore-former. Its amount ranged from 0 to 30 part. Porous SRBSNs were fabricated by post-sintering at various temperatures where the porosity was controlled at $12{\sim}52%$. The strong tendency of increasing porosity with PMMA content and decreasing porosity with sintering temperature was observed. Measured pore-channel diameter increased $(0.3{\rightarrow}1.1{\mu}m)$ with both PMMA content and sintering temperature.

• 전기학회논문지
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• 제59권7호
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• pp.1194-1198
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• 2010

A high temperature superconducting power cable (HTS power cable) was applied large current capacity by no resistance in normal state. Fault state was risen out of over-current but, it was limited to resistance. this study was modeling equivalence, and unbalanced state analyzed operating charateristics of HTS power cable. The equivalence model was composed superconductor, shield, and former part. This model simulation was appeared conductor and shield current in normal state, but fault state was appeared former current as rise current by resistance. so it need to sufficiently influenced the quench characteristic when the former design.

• 한국지역사회생활과학회지
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• 제12권1호
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• pp.23-27
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• 2001

This study is designed to find out the physicochemical quality and the morphological features of Korean wheat flour and imported wheat flour with a view to shed light on their difference. In terms of components, Korean wheat flour and imported wheat flour are similar, but the latter turns out to be better than the former when it comes to crude protein, the ratio of water absorption and the power of maintenance. Yet Korean wheat flour turns out to be better than imported wheat flour. In terms of the chromaticity of wheat flour, the latter turns out to be higher than the former when it comes to L value, while the former turns out to be higher than the latter when it comes to a value and b value. In terms of the morphological features of wheat flour, both are in the shape of an oval with starch particles irregularly attached to gluten. And imported wheat flour is getter than Korean wheat flour in terms of the size of particles.

• 대한기계학회논문집A
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• 제27권9호
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• pp.1589-1596
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• 2003

In this paper, we performed the improvement study for the dynamic characteristics enhancement of the motor stator coil vertical winding machine. The dynamic characteristics improvement was done by means of the optimized design and the weight reduction of the flyer configuration, modified design of the servo control system for the flyer and the former actuation, and the development of jump timing digital circuit for the reduction of former jumping error. As the results, the maximum winding speed pattern of the developed machine was attained up to 3000rpm and also reduced the jumping error. In conclusion, domestic design technology for manufacturing the motor coil vertical winding machine was established through this study.

• Journal of Communications and Networks
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• 제6권1호
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• pp.78-87
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• 2004

This paper presents deterministic, worst-case analysis of a queueing system whose multiple homogeneous input streams are regulated by the associated leaky buckets and the queueing system that has a single stream regulated by the jumping-window. Queueing delay averaged over all items is used for performance measure, and the worst-case input traffic and the worst-case performance are identified for both queueing systems. For the former queueing system, the analysis explores different phase relations among leaky-bucket token generations. This paper observes how the phase differences among the leaky buckets affect the worst-case queueing performance. Then, this paper relates the worst-case performance of the former queueing system with that of the latter (the single stream case, as in the aggregate streams from many users, whose item arrivals are regulated by one jumping-window). It is shown that the worst-case performance of the latter is identical to that of the former in which all leaky buckets have the same phase and have particular leaky bucket parameters.

• 한국식품조리과학회지
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• 제2권2호
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• pp.32-42
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• 1986

Two Tongil type rice varieties and two Japonica rice varieties were prepared and experimented to investigate the effect of physicochemical properties on rice palatibility. Obtained results are as follows; (1) Width and thickness of unhunlled and unpolished grains of Tongil type rices were shorter than those of Japonica type rices and the length of the former was much longer than the latter. (2) Protein contents of Tonsil type varieties were greater than Japonica ones and amylose contents of the former is less than the latter. Alkali digestibility of them showed no significant differences. These means that the qualities of Tongil rices are not less than Japonica ones. (3) Sensory evaluation test showed that Japonica type rices are more excellent than Tongil types in expansion, glutinosity, flavour and taste while the former is inferior to the letter in gloss. (4) Preconceived ideas on the shape of rice seemed to affect most on its palatability.

• Toxicological Research
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• 제30권2호
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• pp.91-97
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• 2014

This study aimed to identify changes in the level of neuropeptides among current smokers, former smokers, and individuals who had never smoked, and how smoking habits affect obesity and metabolic syndrome (MetS). Neuropeptide levels, anthropometric parameters, and metabolic syndrome diagnostic indices were determined among male workers; 117 of these had never smoked, whereas 58 and 198 were former and current smokers, respectively. The total sample comprised 373 male workers. The results obtained from anthropometric measurements showed that current smokers attained significantly lower body weight, body mass index, waist circumference, and abdominal fat thickness values than former smokers and those who had never smoked. Current smokers' eating habits proved worse than those of non-smokers and individuals who had never smoked. The level of brain-derived neurotrophic factor (BDNF) in the neuropeptides in the case of former smokers was $23.6{\pm}9.2pg/ml$, higher than that of current smokers ($20.4{\pm}6.1$) and individuals who had never smoked ($22.4{\pm}5.8$) (F = 6.520, p = 0.002). The level of adiponectin among former smokers was somewhat lower than that of current smokers, whereas leptin levels were higher among former smokers than current smokers; these results were not statistically significant. A relationship was found between adiponectin and triglyceride among non-smokers (odds ratio = 0.660, ${\beta}$ value=-0.416, p < 0.01) and smokers (odds ratio = 0.827, ${\beta}$ value=-0.190, p < 0.05). Further, waist circumference among non-smokers (odds ratio = 1.622, ${\beta}$ value=0.483, p < 0.001) and smokers (odds ratio = 1.895, ${\beta}$ value=0.639, p < 0.001) was associated with leptin. It was concluded that cigarette smoking leads to an imbalance of energy expenditure and appetite by changing the concentration of neuropeptides such as adiponectin, BDNF, leptin, and hsCRP, and influences food intake, body weight, the body mass index, blood pressure, and abdominal fat, which are risk factors for MetS and cardiovascular disease.

• 보존과학회지
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• 제33권4호
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• pp.297-312
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• 2017

고대 제철 공정에서 원광석 내의 철과 기타 광물의 분리가 원활하게 이루어질 수 있도록 조재제를 첨가하는 경우가 많다. 하지만 조재제 첨가 유무를 판단할 수 있는 정확한 기준이 될 만한 자료가 부족한 실정이다. 따라서 본 연구에서는 조재제 첨가에 따라 달라지는 슬래그의 재료학적 특성을 파악하기 위해 제련 실험을 진행하였다. 총 3차례 진행된 실험에서 산출된 슬래그의 미세조직을 관찰하고 성분을 분석하였다. 1차 실험은 조재제를 첨가하지 않았으며, 산출된 슬래그의 전철량은 39.45~52.94 wt%로 확인되었다. 조재제를 첨가한 2, 3차 실험에서는 34.89~38.92 wt%로 감소하였다. 미세조직 분석 결과 2, 3차 실험에서는 철산화물 이외에 Gehlenite, Hercynite와 같은 CaO 화합물이 나타난다. 비금속개재물 성분 간 비율을 비교한 결과, 1차 실험의 유리질바탕의 $CaO/SiO_2$ 값이 0.42를 기준으로, 이보다 높을 경우 조재제를 첨가하였을 것으로 판단된다. $Al_2O_3/SiO_2-CaO/SiO_2$ 비교 분석한 결과, $Al_2O_3-SiO_2$ 비율은 유사한 제련공정 시스템(원광, 노벽, 연료)을 판단하는 지표로 활용할 수 있을 것으로 본다.

• 토지주택연구
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• 제5권4호
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• pp.225-234
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• 2014

군사시설 이전부지는 근본적으로 공공 시설적 성격을 띄고 있어 공공 복리를 위한 활용 요구도가 높아지고 있으며, 이로 인해 공원으로 조성하는 사례가 증가하고 있다. 군사시설 이전부지에 대한 공원조성 사례를 분석한 결과 몇가지의 시사점을 도출하게 되었다. 공원조성의 목표는 도시재생의 개념 및 지역활성화 차원에서 접근할 필요가 있다. 이전부지를 전면 개조하는 방식보다는 기존 시설들을 최대한 재활용하여 경제적 이득을 취하고 동시에 지역정체성과 역사성을 재현할 필요가 있다. 공원의 규모가 대형화 되고 있어 단일시설 및 프로그램 보다는 복합공간으로 조성해 줄 필요가 있으며, 공원조성에 막대한 비용이 소요되므로 단계적으로 공원을 조성하는 방안을 고려할 필요가 있다. 군사시설이 지니고 있는 특수한 상황으로 공원조성 과정에서 현장조사가 미흡하여 설계변경 또는 오염처리에 막대한 비용이 소요되므로 사전에 이를 고려할 필요가 있다. 또한, 민간사업자에게 일부 부지에 대해 개발권을 위임하고 개발이익으로 공원조성과 운영관리비를 충당하는 방안도 검토가 필요하다. 군사시설 이전기지는 다양한 이해관계에 놓여 있으므로 사업추진과정에서 민관협치의 의사결정기구를 운영하는 방안을 고려할 필요가 있다. 다양한 재원조달과 수익사업 확대, 봉사 및 후원 활성화, 트러스트 및 비영리 단체의 공원운영 관리 참여 확대 등을 위해서는 도시공원 관련제도의 보완이 요구된다.