• Current Optics and Photonics
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• 제7권2호
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• pp.119-126
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• 2023

The vibratory and rotational levels of many biological macromolecules lie in the terahertz (THz) band, which means that THz techniques can be used to identify and detect them. Moreover, since the biological activity of most biomolecules only becomes apparent in aqueous solution, we use microfluidic technology to study the biological properties of these biomolecules. THz time-domain spectroscopy was used to study the THz absorption characteristics of graphene oxide (GO) aqueous solution at different concentrations and different exposure times in fixed electric or magnetic fields. The results show that the spectral characteristics of the GO solution varied with the concentration: as the concentration increased, the THz absorption decreased. The results also show that after placing the solution in an external electric field, the absorption of THz first increased and then decreased. When the solution was placed in a magnetic field, the THz absorption increased with the increase in standing time. In this paper, these results are explained based on considerations of what is occurring at the molecular scale. The results of this study provide technical support for the further study of GO and will assist with its improved application in various fields.

• Computers and Concrete
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• 제31권5호
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• pp.371-384
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• 2023

Precast roofing systems employing prestressed elements often serve as smart structural solutions for the construction of industrial buildings. The precast concrete elements usually employed are highly engineered, and often consist in thin-walled members, characterised by a complex behaviour in fire. The present study was carried out after a fire event damaged a precast industrial building made with prestressed beam and roof elements, and non-prestressed curved barrel vault elements interposed in between the spaced roof elements. As a consequence of the exposure to the fire, the main elements were found standing, although some locally damaged and distorted, and the local collapse of few curved barrel vault elements was observed in one edge row only. In order to understand and interpret the observed structural performance of the roof system under fire, a full fire safety engineering process was carried out according to the following steps: (a) realistic temperature-time curves acting on the structural elements were simulated through computational fluid dynamics, (b) temperature distribution within the concrete elements was obtained with non-linear thermal analysis in variable regime, (c) strength and deformation of the concrete elements were checked with non-linear thermal-mechanical analysis. The analysis of the results allowed to identify the causes of the local collapses occurred, attributable to the distortion caused by temperature to the elements causing loss of support in early fire stage rather than to the material strength reduction due to the progressive exposure of the elements to fire. Finally, practical hints are provided to avoid such a phenomenon to occur when designing similar structures.

• Asia Marketing Journal
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• 제15권2호
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• pp.99-116
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• 2013

This study examines whether product promotions are influenced by the market standing of promoted products, using social comparison theory (upward versus downward comparisons). It is hypothesized that people in possession of a product that is inferior to the one on promotion express less discomfort about the promotion and use the information more than do people in possession of a superior product. People in possession of an inferior product may also exhibit more positive attitudes toward the product on promotion, but may show poorer attitudes toward their own possessed product than do people with a superior product. This is because people in an inferior socioeconomic position show a strong motivation to improve themselves through upward social comparison, whereas people in a superior socioeconomic position maintain a strong sense of superiority in downward social comparison, which suggests strong endowment effects. The findings mainly support the hypotheses, and suggest that sales promotions are more effective for people who currently own an inferior product, but not for people with a superior product, who have a strong motivation to maintain their sense of superiority. The findings also imply that, in order to attract consumers in the superior market, managers for inferior products need to turn to methods other than sales promotions, which may include introducing a new brand or sub-brand, or emphasizing luxury and modern features. In contrast, managers for superior products may emphasize product functions and attributes of superior products in their promotions, as people with inferior products may consider such information as benefits of the superior products.

• 미술자료
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• 제99권
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• pp.50-71
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• 2021

부여 동사리사지 오층석탑은 수도 개성 양식 계열의 남방한계선을 점하는 중요한 위치에 건립된 고려 전기 탑이다. 갑석 받침인 부연의 사선형 곡면 처리 등에서는 고려 개경 중심의 탑에서 보이는 고려중앙 양식의 특징을 잘 살펴볼 수 있었으며, 11세기 석탑과 양식을 공유하는 특징들도 뚜렷하게 관찰되었다. 하층기단의 안상문에서는 고려 1028년(현종 19)에 대대적으로 중수된 것으로 추정되는 부여 정림사지에 있는 석불좌상 대좌와, 천안의 천흥사지 당간지주에서 동일한 문양과 치석 수법이 조사되어, 동사리사지 오층석탑 건립 연대를 11세기로 추정했다. 부여 동사리사지는 금강 인근에 위치해 고려의 조운제도상 중요한 교통로이며, 고려 왕실의 원찰인개태사로 가는 길목에 자리잡고 있어 고려 현종대(1009~1031) 부여 정림사지가 크게 중수되고 동사리사지도 주요 거점으로 부각되면서 석탑이 조성되었을 것으로 짐작된다. 또한 동사리사지 석탑은 1021년(현종 12) 천안의 홍경사와 홍경원의 창건과 관련된 것으로 추정되는 인근의 천흥사지 석탑 및 당간지주와도 양식을 공유하고 있어 이를 통해 개경 양식의 유입 루트도 살펴볼 수 있었다. 부여 동사리사지 오층석탑은 고려 11세기 문화의 우수성을 보여주는 이 지역의 또 하나의 석조미술품이다. 수도 개경의 거대한 현화사 석등과 석탑과 비견되는 고려 초 논산 개태사나 관촉사, 부여 대조사 석조미륵보살입상 등의 거불(巨佛)과 함께 이 석탑 역시 고려 특유의 당당하고 자신감 있는 미감을 보이고 있다. 11세기 활발한 지역간 문화교류의 배경 아래 부여 동사리 지역은 고려 개경의 불교문화 영향권 아래 완숙한 문화 역량을 총 발휘해 경쾌하고 날렵하며, 엄정하면서도 세련된 이러한 석탑을 탄생하게 했을 것으로 추정된다.

• 한국콘텐츠학회논문지
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• 제13권3호
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• pp.381-391
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• 2013

본 연구의 목적은 70세 이상의 여성고령자들에게 재가운동 프로그램(home support exercise program)을 16주간 주3회씩 실시하여 생활기능 체력과 건강관련 삶의 질(SF-36)에 대한 주관적 평가에서의 변화를 살펴보고자 하였다. 실험군(총17명, 평균나이:79.4)과 통제군(총17명, 평균나이:80.7)은 부산시 연제구에 거주하며 신체적 외상이나 거동에 불편함이 없고, 연구 참여에 동의한 여성 고령자로 구성하였다. SAS 9.2 통계 패키지를 활용하여 집단간 기술통계와 동일성 검증 및 사전측정을 공변량으로 한 공분산 분석을 실시하였다. 그 결과는 다음과 같다. 첫째, 실험군이 통제군에 비해 덤벨 들기, 일어섰다 앉기, 2.24m 왕복달리기, 2분간 제자리 걷기 항목에서 통계적으로 유의하게(p<.001) 증가한 것으로 나타났다. 둘째, 유연성을 측정하는 등 뒤 손잡기 항목에서는 실험군에서 유의할 만한 변화가 없는 것으로 제시되었다. 이러한 점은 재가운동프로그램에 유연성을 향상시킬 수 있는 운동항목을 추가하여 보완할 필요성이 있음을 시사하는 것이었다. 셋째, SF-36을 통한 건강관련 삶의 질에 대한 주관적 평가에서는 8개의 모든 하위요인에서 실험군과 통제군간에 유의할 만한 차이가 없는 것으로 제시되었다. 다만 통증과 활력 하위요인에서 운동을 처방받은 실험군이 통제군에 비해 p<.10 수준에서 향상된 것으로 나타나 긍정적인 변화를 미세하게 시사하였다.

• 안보군사학연구
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• 통권5호
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• pp.1-45
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• 2007

Reserved forces of ROKA are in charge of replacement of TOE in the wartime and mission of rear area operation. But there is institutional inertia in the law and organization oriented to fill human resources rather than take mission. We need to prepare for the investment and arrangement of reserved forces as military power that would be replaced standing forces. In this portion, to reinforce reserve forces elite, First, efficient mobilization regulations and systems are suggested. I covered a maintenance of relevant mobilization ordinances which need to legislated and approved by national assembly for wartime and development of mobilization system which might lose the appropriate time for mobilization due to complicated declaration procedures and measures to overcome the panic at the initial stage of the war and organization and employment of nationwide transportation system and mobilization center. To ensure efficient resource management and mobilization of reserve forces with a number of approximately 3 million, there's a necessity of organization for integration and conciliation. To make it real, I suggested establishing and employing the mobilization center, on first phase, employ the mobilization center focusing on homeland divisions, on second phase, it is advisable to convert to national level mobilization system and develop to central mobilization center focusing on national emergency planning committee. During peacetime, in conjunction with Mobilization Cell, mobilization center can conduct resource survey and integrate and manage mobilization resources and take charge of mobilization training of subordinate units, and during wartime, in conjunction with mobilization coordination team and Cell, can ensure the execution of mobilization. Second, Future oriented reserve forces management system such as service system of reserve forces and support system of homeland defense operations. Current service and trainings of reserve forces by the year have very low connection, as it is very complex to manage the resources and trainings, and service and training lack the equity, re-establishment of service system is required. Also in an aspect of CSS and cultivation support for reserve forces, as the scope and limitation of responsibility between the armed forces and autonomous organization is obscure, conditions to conduct actual-fighting exercises are limited. Concentrated budgetting is extremely difficult because reserve forces training fields are scattered nationwide, and facilities and equipments are rapidly getting older. To improve all these, I suggest the organization of homeland defense battalion with a unit of "City-Gun-District" and supporting the local reserve forces. Conduct unit replacement or personal replacement for those who have finished their 1 or 2 years and homeland defense operation duty for those with 3-5 years for consistency and simplification. Third, I suggest Future oriented Reserved Training(FRT) and Training Center oriented training management to establish a reliable reserve training. Reserves carry out expansion of unit, conventional combat mission, homeland defense and logistics support during wartime, and actual-fighting exercise, and disaster relief, peace keeping activities. Despite diverse activities and roles, their training condition still stays definitely poor. For these reasons, Modernization of weapons and facilities through gradual replacement and procurement is essential to enhance mobilization support system.

• 한국운동역학회지
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• 제25권2호
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• pp.183-190
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• 2015

Objective : Walking with a Material handling is an activity frequently undertaken by agricultural workers in Korea, due to the nature of their work. This study aimed to investigate differences in biomechanical variables according to the mechanical alignment of the lower limbs when walking with a heavy load, and to use this as basic data in the design of various working environments to reduce the skeletomuscular burden on the knee joint. Method : The study subjects comprised of 22 right-foot dominant adult men and women aged between 20 and 23 years. The subjects were divided into a varus or valgus group according to the mechanical alignment of the lower limb by using radiographic findings. The subjects walked without any load and with a load of 10%, 20%, or 30% of their body weight held in front of them. The Kwon3d XP program was used to calculate biomechanical variables. Results : The flexion/extension moment of the knee joint showed a decreasing trend with increased load, irrespective of the mechanical alignment of the lower limb, while the varus group did not show normal compensatory action when supported by one leg at the point of maximum vertical ground reaction force. In addition, in terms of the time taken, subjects showed no difficulties in one-foot support time up to 20%/BW, but at 30%/BW, despite individual differences, there was an increase in single limb. The increased load resulted in a decrease in the ratio of standing phase to ensure physical stability. The valgus group showed a trend of increasing the stability of their center of mass with increasing load, through higher braking power in the early standing phase. Conclusion : In conclusion, although there was no statistical difference in biomechanical variables according to the mechanical alignment of the lower limbs, the varus group showed a more irregular walking pattern with a Material handling than the valgus group, partially proving the association between lower limb alignment and walking with a Material handling.

• The Journal of Korean Physical Therapy
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• 제13권2호
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• pp.467-475
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• 2001

The purpose of this study was to evaluate changes of static lumbar lordosis by different heel heights in normal adults and patients with herniation of nucleus pulposus(HNP). The lumbar lordosis was examined while standing on barefoot, on heel support with 4cm heel, and with 8cm heel in 10 normal adults and 10patients with HNP. Standing lumbar lateral view was performed by 20 minutes adaptation with corresponding shoe types. The angle of lumbar lordosis was taken with Wiltse and Winter's method(angles between upper margin of 1 st lumbar body and upper margin of 5th lumbar body). The results of this study were as follow: 1. Significant statistical decrease in lumbar lordosis was observed as heel heights were increased from barefoot to 8cm high heel in normal adults(p<0.05). 2. There were no significant differences in lumbar lordosis according to three different heel heights in patients with HNP(p>0.05). 3. In comparison of barefoot, There were statistically significant decrease in HNP patients compared with normal adults in terms of lumbar lordosis(p<0.05).

• 한국산학기술학회논문지
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• 제19권6호
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• pp.664-668
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• 2018

특수구조물 중에서 특히 높은 독립적 구조물은 낙뢰에 의한 뇌격을 받을 가능성이 높다. 특수 구조물은 대체적으로 국가 산업시설물에 속하므로 낙뢰로 인한 피해는 사회적 경제적 손실이 막대하다. 이러한 낙뢰 피해 방지를 위해 낙뢰 보호시설을 설치하였으나 2015년도에 서해 대교의 지지케이블에 낙뢰로 인한 화재가 발생하여 많은 경제적 손실을 초래하였다. 이에 낙뢰 보호 시스템의 설계는 구조물에 낙뢰 위험을 분석 한 후 보호 조치를 수립해야한다. 뇌격에 대한 위험도 평가에 대한 국제적 규격은 국제전기기술위원회(IEC) 규격이 전 세계적인 규격의 근간을 이루고 있으며, 특히 해외 국가규격이나 기준은 IEC 기준으로 낙뢰 위험도 평가를 실시하여 낙뢰 보호대책시 적용하고 있다. 국내에서도 KS C IEC 62305 규격을 적용하여 위험성평가와 피뢰보강을 위한 기초자료로 활용하고, 낙뢰 보호 시스템을 설계한다. KSC IEC 측정방법으로 국내 특수교 리스크 평가에 대한 결과로는 물리적 손상 및 전자계시스템 위험 특수교는 평가대상 전체 교량 77개 교량 중 7개 교량에서 허용위험도가 높은 것으로 보고되었다. 본 논문에서는 높고 독립적 구조물의 위치에 따라 낙뢰 수에 대한 실제 정보 수집 시스템을 운영하는 모델링 시스템을 제안하기 위해 실제적인 낙뢰 정보를 분석하고 기상 관측소에서 제공 한 낙뢰수와 높은 구조물에 직접 도달하는 위험한 낙뢰 수를 비교하여 검증하는 방법을 검토하였으며, 지상에 직접적으로 도달한 낙뢰수에 따른 낙뢰위험도 산출시 확률적 보정률을 모니터링하여 적용함으로써 실효적인 낙뢰위험도 평가를 할 수 있도록 제안하고자 한다.

• 한국과학교육학회지
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• 제39권1호
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• pp.73-88
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• 2019

본 연구에서는 자생적 온라인 교사 공동체 인디스쿨에 축적되어 온 과학 교수 관련 질문 게시글을 분석함으로써, 초등교사가 겪는 과학 교수 관련 어려움을 파악했다. 이를 위해, 3~6학년 물리 영역 및 과학 전반에 해당하는 질문 게시글 409개를 초등교사의 탐구 기반 과학 교수 역량을 다룬 Alake-Tuenter et al.(2013)의 틀을 수정 보완한 질문 분석틀로 분석하였고, 과학-SMK와 과학-PCK의 구성요소별 어려움을 탐색하였다. 분석 결과, 과학-SMK 질문이 과학-PCK 질문 보다 더 많이 나타났으며, 연도별로는 교육과정이 변화하는 시기였던 2014년과 2015년도에, 단원별로는 렌즈 단원에 대한 질문이 가장 많았다. 과학-SMK 측면에서 4년 이상 지속적으로 나타난 어려움은 렌즈와 전기 단원에 대한 것이다. 렌즈 단원에서는 투명한 물컵 모양의 물체가 렌즈로 작동하는 원리와 볼록렌즈에서 상의 생성 과정 등 과학적 사실과 개념의 적용 등이, 전기 단원에서는 '전류의 흐름 변화에 따른 나침반의 움직임 변화'와 '전구의 직렬연결'에서 예상치 못한 탐구 결과 오류 등이 초등교사가 오랜 기간 겪어온 과학-SMK 측면의 어려움으로 나타났다. 과학-PCK 측면에서 4년 이상 지속적으로 나타난 어려움은 과학수업 운영 전반에 대한 것으로, 수업자료 및 학기말 활동구성 아이디어의 요청과 교육과정 운영 지침의 이해 등이 있다. 자생적으로 생성 및 운영되고 있는 인디스쿨의 과학 교수 관련 질문 게시글에서 오랫동안 해결되지 못한 채 반복되고 있는 초등교사들의 실제적인 어려움을 파악해 이를 해결하고 도움을 줄 수 있는 과학 교수 지원 체제를 구축하는 것이 필요할 것이다.