• 항공우주기술
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• 제3권1호
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• pp.242-250
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• 2004

군용뿐만 아니라 상업용으로 헬리콥터의 사용 빈도가 높아지면서, 무엇보다 헬기의 안정성이 가장 중요한 요소가 되었다. 단순히 조종사에 의한 시계 비행을 할 경우 야간 운항이 불가능하며 안개, 눈, 비 등의 기후 조건에서는 매우 불안전하다. 그리고 주간 비행 중에도 전선과 같은 장애물로 인한 사고가 발생하고 있다. 그러므로 헬기의 안전운항을 위해서는 단순한 시계 비행에서 벗어나 장애물 탐지 시스템을 이용한 자동항법 개념을 도입해야 한다. 자동항법을 위한 장애물 탐지 시스템은 안개, 눈, 비 등의 기후 조건하에서 주간 및 야간에도 정상적으로 동작해야 한다. 본 논문에서는 밀리미터파 레이다 시스템을 이용하여 전선 장애물의 탐지 기술 획득을 위한 기초 연구를 수행하였다. 서론에서는 헬기 운항에 장애가 되는 요소들을 탐지하기 위한 여러 방법들에 대해서 살펴봤다. 본론에서는 밀리미터파를 이용한 장애물 탐지 시스템과 실험 장치에 대해서 다루고 결론에서는 실험 결과 및 향후 연구 방향에 대해서 다루고 있다.

• 한국식품조리과학회지
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• 제22권6호통권96호
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• pp.832-839
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• 2006

Kugija was added to Nabak kimchi to improve the quality and preservation and the optimum addition level was assessed. Kugija extract was prepared by boiling kugija fruits, at different ratios (0, 1, 3, 5, 7%; w/v) in water for 30 minutes. The changes in the physicochemical properties of the Nabak kimchi were measured during storage for 25 days at 10?, and compared to a control (without kugija). The pH was decreased in all treatments. Following the fermentation of Nabak kimchi, the total acidity values were inversely proportional the pH changes according to the nature of mutual dependence. However, in short term, during the initial 7 days of fermentation, the total acidity values decreased with increasing concentrations of kugija extract, whereas the trend was reversed after day 10. Total vitamin C content was directly proportional to the concentration of kugija extract and was decreased with the laps of fermentation. Up to day 25, 7% treatment showed the highest vitamin C content, but at 25 days 1% and 3% treatments ranked the first. The mont of reducing sugar was proportional to the concentration of kugija extract however, the difference of values between all treatments became almost indiscernible after day 25. Turbidity values were generally increased in all samples during fermentation period, although only to a limited extent. The lowest turbidity was shown at 3% treatment up to day 16. Total color difference values were increased up to day 16, but then decreased. The optimum level of kugija extract in Nabak kimchi, as determined through these experiments, was between 1 to 3% per added water content, and was preferably 3% for color and fermentation-retarding effect of the product. Kugija extract could be applied for improving the quality and preservation of traditionally prepared Nabak kimchi.

• 산업경영시스템학회지
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• 제43권3호
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• pp.243-253
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• 2020

As economic profits and social influences of firms grow with economic development and their organizational expansion, consumers increasingly require firms to have their social responsibility. Because social responsibility strongly influences corporate reliability, consumers' intention to purchase, customer loyalty to the products and the recognition of an ethical firm have gained attention as a concept of strategical importance. The prosperity of society should be proceeded for the sustainable development of a firm and the necessity of social responsibility should be emphasized to achieve virtuous circle structure that promotes growth. Additionally, the social responsibility should be proceeded to form trust on a firm. It is very important to change the recognition of consumers to purchase products and increase the profit of a company. This study aims to analyze how social responsibility properties of firms (economic, ethical, discretionary, and legal aspects as low-level factors of social responsibility which Carroll (1979) defined) affect corporate reliability and purchase intention. The analysis found that consumers trust in firms are positively influenced by ethical responsibility (0.391), economic responsibility (0.293), legal responsibility (0.251), and discretionary responsibility (0.248). The relationship between sub-factor of social responsibility and purchase intention is not significantly influenced by other explanatory variables. Corporate trust exerts a direct influence on purchase Intention (0.456). The social responsibility of a firm didn't influence a direct purchase intention. It was found that it brought positive effect on the purchase intention in the course of forming trust. This study suggests that firms should make efforts to understand the relationship between corporate trust and purchase intention along with the characteristics of social responsibility that consumers recognize and improve management strategies for mutual complementary interests.

• 한국통신학회논문지
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• 제37권6C호
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• pp.512-519
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• 2012

새로운 위성항법 시스템 신호를 설계함에 있어 기존에 연구되고 서비스되고 있는 위성항법 시스템과의 간섭영향에 대한 분석이 필요하다. 동일한 대역을 사용하는 GPS, GALILEO, Compass 등 다양한 위성항법 시스템 간에는 스펙트럼이 중첩되는 영향으로 상호 간 간섭이 발생한다. 이에 본 논문에서는 포화되어 진입이 어려운 L1 대역을 배제하고 새로운 위성항법 시스템이 사용할 수 있는 무선항행위성 주파수 대역으로 L2밴드를 선정하였다. 그리고 GPS L2 시스템 신호와 스펙트럼 분할 계수가 가장 작은 BOCcos(15,2.5) 신호를 대입하고, 한반도 상공에 정지한 위성을 가정하여 그 영향을 모의실험을 통해 분석하였다. 그 결과 L1밴드의 다양한 서비스 간의 간섭 영향과 비교해 상호 간 간섭에 의한 수신신호 전력의 감소가 매우 작음을 확인할 수 있었다.

• 한국방재학회 논문집
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• 제8권1호
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• pp.89-96
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• 2008

본 연구는 되 메움 된 굴착 양측 벽이 비대칭으로 경사진 경우에 대하여 벽체간의 폭, 벽면경사각, 상대밀도, 벽면마찰각의 크기를 변화시켜 Kellogg의 이론과 이를 보완한 수정식으로 토압을 산정하고 또한, 벽면마찰반력을 고려한 토압 식을 제안하여 상호간 거동을 구명하였다. 이들 결과로부터 구한 지중 토압을 검증하기 위하여 총 62종류의 모형실험을 수행한 결과를 이론식에 의한 거동과 비교, 검토하였다. 본 연구결과 양측 벽이 비대칭으로 경사진 경우, 되 메움 토압에 가장 큰 영향을 미치는 요소는 벽체경사각의 크기였으며, 또한 되 메움 공간이 협소할수록 그리고 수평면과 이루는 벽체의 경사각이 클수록 벽 마찰의 영향이 크게 나타났다. 한편, 실측토압과 가장 근소한 차이를 나타낸 것은 벽면마찰반력을 고려한 제안 식으로 구한 경우였으며 또한, 벽면사이의 폭이 좁은 경우 아칭효과가 크게 나타나 실측토압 및 제안된 이론토압모두 지중 토압과 가장 근소한 차이를 나타내었다.

• 대한의용생체공학회:의공학회지
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• 제39권6호
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• pp.237-242
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• 2018

$^{18}F$-fludeoxyglucose PET (FDG-PET) can help finding an abnormal metabolic activity in brain. In this study, we evaluated an efficiency of volume- and cortical surface-based analysis which were used to determine whether standardized uptake value ratio (SUVR) of FDG-PET was different among Alzheimer's disease (AD), mild cognitive impairment (MCI), and healthy control (HC). Each PET image was rigidly co-registered to the corresponding magnetic resonance imaging (MRI) using mutual information. All voxels of the co-registered PET images were divided by the mean FDG uptake of the cerebellum cortex which was thresholded by partial volume effect (>0.9). Also, the SUVR value of each vertex was linearly interpolated from volumetric SUVR image which was thresholded by gray matter partial volume effect (>0.1). Lobar mean values were calculated from both volume- and cortical surface-based SUVRs. Statistical analysis was conducted to compare two measures for AD, MCI and HC groups. Even though the results of volume (SUVR_vol) and cortical surface-based SUVR (SUVR_surf) analysis were not significantly different from each other, the latter would be better for detecting group differences in SUVR of PET.

• 한방안이비인후피부과학회지
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• 제34권3호
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• pp.70-79
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• 2021

Objectives : The purpose of this study is to investigate the possibility of using herbal medicine for the management of psoriasis focusing on lipid metabolism. Methods : We reviewed studies about pathophysiology, and medical treatment of psoriasis, the relationship between psoriasis and metabolic syndrome and lipid metabolism, and herbal medicine on Pubmed and Google scholar. Results : Psoriasis is a chronic multi-organ inflammatory disease not limited to skin, and steroids, immuno-suppressants, and biological agents are used. It is known that psoriasis and metabolic syndrome act as mutual risk factors, and lipid metabolism are involved in psoriasis. The effects of various single herbal preparations and complex herbal extract, decoction on improving lipid metabolism have been consistently reported, and there was an improvement of psoriatic skin lesions and improvement of blood lipid levels through herbal medicine. Conclusions : Herbal medicine research in psoriasis has focused on the anti-inflammatory effect and the suppression effect of certain immune mediators. However, considering that psoriasis is affected by lipid metabolism and side effects of Western medicines, the use of herbal medicines for the purpose of controlling lipid metabolism in psoriasis is useful in aspects of reducing side effects of concurrent Western medicine, improving the severity of psoriasis, and managing metabolic risk factors.

• 아태비즈니스연구
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• 제13권1호
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• pp.103-123
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• 2022

Purpose - This study investigates the effects of earnings management, related party transactions between chaebol affiliates on earnings management and ESG score on their profitability using return on assets (ROA). Design/Methodology/Approach - We use data including ESG (Environmental, Social, and Corporate Governance) score of the Korea Corporate Governance Service(KCGS), and financial data of 10,145 firm-year observations from the Total Solution 2000 (TS 2000) and Korea Companies-Information Service (KOKOInfo), and apply the finite lagged models to investigate the long-term effects of related party transactions between chaebol affiliates of earnings management on ESG scores and corporate performance. Furthermore, to take into consideration the simultaneous mutual effects on each other of main variables, we introduce finite distributed lags of five years. Findings - First, ESG-rated firms have a higher total asset return than non-ESG-rated firms. Second, chaebol firms have a higher profitability than non-chaebol firms. Third, profit management of related party transactions between affiliates within a chaebol has a positive effect on the short-term profitability and a negative effect on the long-term profitability. Fourth, chaebol ESG firms have a lower impact on profitability due to rating up (down) than non-chaebol ESG firms. Research Implications or Originality - Based on the above results, it can be concluded that firms used related party transactions for earnings management, the effects of related party transactions change over time, and chaebol firms manipulate earnings through related party transactions and ESG scores.

• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1239-1246
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• 2022

This paper introduces the effect of grease on the degradation characteristics of bearings used as key components of packaging equipment and automation systems. Bearings parts are installed to fix and support the rotating body of the system, and performance degradation of the bearings has a great effect on the life of the system too. When bearings are used in various devices and systems, the grease is applied to reduce friction and improve fatigue life. Determining the type of lubricant (grease) is important because it has a great influence on the operating environment and lifespan and ensures long lifespan of systems and facilities. However, studies that simultaneously compared and analyzed the change in mechanical degradation characteristics and the comparison of chemical degradation characteristics according to grease types under actual operating conditions are insufficient. In this paper, three types of small harmonic drive, high-load reducer, and low-load reducer grease used in power transmission joint modules are experimentally selected and finally injected into ball bearings with a load (19,500N) to improve bearing durability. Degradation characteristics were tested by attaching to test equipment. At this time, after the durability test under the same load conditions, the mechanical degradation characteristics, that is temperature, vibration according to the three greases types. In addition, the chemical degradation characteristics of the corresponding grease was compared to present the results of mutual correlation analysis.

• 한국체육학회지인문사회과학편
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• 제53권5호
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• pp.521-531
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• 2014

본 연구는 한국인 20대의 남성과 여성을 대상으로 보행 분석상의 표준화 방법 중의 하나인 dimensionless number의 효과를 검정하고 이를 통해 성별간 보행형태를 분석하는데 목적이 있다. 피험자는 기술표준원에서 제공하는 한국인 표준체형 및 연령 분류 체계에 맞춰 선정하였으며, 3차원 동작분석 시스템이 사용되었다. 데이터 분석을 위한 소프트웨어로는 Cortex, OrthoTrak, Matlab, Excel이 사용되었으며 통계검정을 위해서 SPSS를 사용하였다. 분석 결과를 살펴보면, Hof(1996)의 dimensionless number 변환을 통한 20대 성별 간 보행 형태는 시·공간 변인인 stride length, step length, stride time, step time, 보행속도(velocity), cadence 모두에서 유의한 차이가 없었으며, 표준화 전·후에 따라 통계분석의 결과가 달라짐을 확인하였다. 따라서 보행 분석에서 데이터의 표준화 방법 중의 하나인 dimensionless number의 적용은 통계학적 검정에 영향을 줄만큼 C.V. 값을 변화시키는 것으로 확인되었다. 본 연구를 통해, 상호 비교를 위한 보행연구에서 dimensionless number를 이용한 표준화 방식은 피험자의 신체적 특성이 분석에 미치는 영향을 제거하고 보다 정확한 통계 검정을 위해서 반드시 요구되는 과정이라는 것을 확인할 수 있었다.