• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.791-794
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• 2010

This study presents channel design of a CDI stack to achieve high removal efficiency in a large scale by applying parallel flow structure with a concentrated stream. The flow pattern in the stack was simulated by COMSOL Multiphysics program. To prove the salt removal performance, a unit cell and 20 cell stacks were tested at a flow rate condition of 18 ml/min and 360 ml/min, respectively. The removal efficiencies of the unit cell and the 20 cell stacks were obtained as 70.8 % and 75.6 %, respectively, with 100 mg/L sodium chloride solution. During the operation of cell test, water pressures of unit cell and 20 cell pair stack maintained in the ranges of 1.1 psi and 1.3~1.5 psi, respectively. It was demonstrated that the parallel cell structure with two concentrated streams can be employed in a large scale CDI for salt removal.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.164-174
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• 2013

It has been seriously difficult to create demand of modular construction because Korean modular method has been considered as container house or lightweight steel house. Actually, barrier factor of modular construction for activation was difficult to produce modular continuously in factories based on stable amount of demands. So, this research found successive factors of modular construction and proposed the method of demand creation through a plethora of case analysis by building types. In addition, this research found the scale of modular potential market. Owners will be able to use this strategy that is proposed in this research when they make a decision about construction system. Also, the modular construction can make potential market in Korea. As a result, modular system producer can make their business strategies and make continuous demand by conjugating the method of creating demand for modular construction which is proposed in this research.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.57-65
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• 2019

If aging apartments are left unimproved through remodeling, the city will be eventually slum. As the government recognizes remodeling as an alternative to reconstruction, the law has been revised mainly to increase the housing area, increase the number of house and allow the vertical extension for making remodeling costs. However, the remodeling is still not activated yet in the market. Therefore, this study analyzes the decision factors of apartment remodeling in Seoul metropolitan area based on Heckman two-stage analysis considering sampling error. Research findings indicate that the decision for remodeling is determined by the characteristics of the household, housing, and time-lapse variables. And also the number of household members, net assets, housing satisfaction, the 11-20, 21-30, and more than 30 years of building are identified as the significant variables as a result of remodeling choice probability analysis. It is noteworthy that the significant variables from then remodeling cost analysis are net assets, area, more than 30 years of building, and unit housing price. It is also notable that the policy, which extend the housing area to cover remodeling cost, are not actually effective to activate the remodeling, and the age in the case of elderly people in Seoul and Gyeonggi-do who are expected to have high net assets and income is not significant variables. This study is expected to provide more objective and reliable implication to the policy makers, the home owner and the investors on the decision making process related to the remodeling project.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.126-143
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• 2013

Myeonghwalsanseong Fortress and Namsansinseong Fortress in Gyeongju are one of the few that have accurate records of when and who constructed the structures. Based on the monument commemorating the construction of Myeonghwalsanseong Fortress and the construction technique and structure of the fortresses confirmed through excavation survey, it can be induced that Myeonghwalsanseong Fortress was built prior to the 7th century. Meanwhile, Namsansinseong Fortress is believed to have been erected in 679, with the exception of one part of the wall found in the northwestern valley that was built during the first construction period of 591. Referring to the construction method of these fortresses in the royal capital, Gyeongju, various recentlystudied fortresses were reviewed to estimate the construction periods. As a result, Haman Seongsansanseong Fortress, which takes similar form with Myeonghwalsanseong Fortress, is believed to have been built during the mid-6th century based on the construction method and supplementary work method(i.e. Bochuk). Yangdongsanseong Fortress in Gimhae and Singisanseong Fortress, similar in their construction method, are also believed to be from the same period. Meanwhile, Jusanseong Fortress of Goryeong, despite the similar construction technique used, the construction technique used for Bochuk or limited Bochuk imply a time gap. Separately, most of the remaining walls of Namsansinseong Fortress appear to date back to the additional construction period, and Sageunsanseong Fortress in Hamyang and Dadaesanseong Fortress in Geoje that show similar construction method are set for the same period. Such conclusion was drawn from straight layer piling using the refined rectangular stones found in the fortress and the supplementary part remaining thereof. In addition, the study discovered a cross-section triangular water hole at Yangdongsanseong Fortress in Gimhae and Sageunsanseong Fortress in Hamyang and the trace of wooden fences constructed before the construction of stone-wall, reaping outcomes rarely found in this region.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.825-836
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• 2022

Micropiles can be used to support additional load in extended building structures. However, their use brings about a risk of exceeding the bearing capacity of existing piles. In this study, pre-compression was applied to distribute the load of an existing building to micropiles, and an indoor loading test was performed to confirm the structural applicability of a wedge-type anchorage device designed to improve its capacity. According to the test results, the maximum strain of the anchorage device was 0.63 times that of the yield strain, and the amount of slip generated at the time of anchorage was 0.11 mm, satisfying structural standards. In addition, using MIDAS GTS, a geotechnical finite element analysis software, the effect of the size of the pre-compression, the thickness of the soil layer, and the ground conditions around the tip on the reaction force of the existing piles and micropiles were analyzed. From the numerical analysis, as the size of the pre-compression load increased, the reaction force of the existing pile decreased, resulting in a reduction rate of up to 36 %. In addition, as the soil layer increased by 5 m, the reduction rate decreased by 4 %, and when the ground condition at the tip of the micropile was weathered rock, the reduction rate increased by 14 % compared with that of weathered soil.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.31-54
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• 2022

This study is to suggest the direction of the spatial change of the university library based on the trend of the spatial change in the university libraries and a survey on the perception of the librarians. For this purpose, the characteristics of the spatial change of the university libraries from 2000 to 2020 were analyzed, and the problems of the spatial change of the university libraries were identified through a survey. As a result of the survey, there was a total of 99 spatial changes in the university libraries nationwide over the past 20 years, including new construction, extension and remodeling. In recent years, it was found that due to the university's budget tightening policy, the university libraries focus on remodeling rather than new construction or extension. The characteristics of the spatial change were analyzed as follows. First, the resting areas have been expanded in the libraries. Second, The libraries are in pursuit of pleasant and comfortable atmosphere. Third, the libraries aim to establish an innovative and creative space. All these changes have been made in order to accommodate the requests of users and increase the number of users. It was also found that spatial change has advantages in these two points: providing various spaces and increasing the number of library visitors. On the other hand, spatial change has the problems such as the increased cost of maintaining the facility and the lack of management manpower. Additionally, a few more problems of spatial change are pointed out: first, spatial change only reflects the trend of the times without making a big change in the services and the actual value of the university library. Second, it has made university libraries standardized losing each library's own characteristics. This study suggests that the spatial change of the university library should secure the distinctiveness of the university library, accommodate various changes, and aim for the symbolism that can prove the value and existence of the university library.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.2
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• pp.245-256
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• 2014

잉어, Cyprinus carpio와 동자개, Pseudobagrus fulvidraco의 상악 하악 수염을 조직학적으로 조사하였다. 동자개의 수염은 연골성 증축(axial rod of cartilage), 신경섬유다발(bundle of nerve fiber), 표피(epidermis), 평활근 층(smooth muscle layer) 및 미뢰(taste bud)로 구성되었으며, 잉어의 수염은 표피, 신경섬유다발, 혈관(blood vessel) 및 미뢰로 구성되었다. 수염 길이에서 잉어는 상악 바깥쪽 수염(second maxillary barbel)이 상악 안쪽 수염(first maxillary barbel) 보다 길게 나타났으며, 동자개는 하악 안쪽(inner mandibular barbel), 상악 위쪽(upper maxillary barbel), 하악 바깥쪽(outer mandibular barbel), 상악 아래쪽(lower maxillary barbel) 순으로 길게 나타났다(P<0.05). 미뢰의 수를 고려하였을 때, 동자개와 잉어간의 미각에 대한 유의적 차이가 없었다(P>0.05). 아울러, 두 어종의 모든 수염에서 수염 상부의 미뢰 수가 하부의 미뢰 수 보다 높게 나타났다(P<0.05). 본 연구 결과, 동자개의 수염은 딱딱하며 굴절성인 수염(flexible and stiff type)이었으며 잉어의 수염은 연하고 유연한 수염(tender and yielding type)으로 파악되었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.452-458
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• 2007

The vertical extension of a building in general remodeling process increases both gravity and seismic loads by simply adding masses to the building. In this study, a vertical extension structural module (VESM) is proposed for enhancing seismic performance of the existing buildings by utilizing the story-increased parts. The proposed VESM is composed of steel column, steel beam, and beam-end rotational damper. The steel columns are connected to the shear walls and transfer the wall rotation in out-of plane to the steel beam, and then the beam-end rotational damper dissipates the earthquake-induced energy. Numerical analysis result from a cantilever beam of which end-rotation is restricted by rotational damper indicates that the displacement, base shear, and base overturning moment of the existing structures showing cantilever behavior can be significantly reduced by using the proposed method. Also, it is observed that friction-type rotational damper is effective than viscous one.

• The Science & Technology
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• v.8 no.3 s.70
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• pp.25-26
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• 1975

한국과학기술정보센터(KORSTIC, 소장 김두홍)는 1980년대 후반에 완전한 자립운영을 실현하기 위한 단계적 시도로 제 1 차 5개년사업계획(1976~1980)을 수립하였다. KORSTIC은 1962년 1월 유네스코 한국위원회에서 출발했고 1964년에는 문교부 산하 사단법인으로 발족되었다. 그후 1967년에 과학기술처 산하로 이관되었으며 재단법인으로 개편하게 되었다. 1969년 한국과학기술 정보센터 육성법의 제정공포로 현 청사(건평 1,548평)에 입사, 정보자료 입수와 자료장비를 갖추면서 1974년 7만여건의 정보자료를 제공해 오고 있다고 한다. KORSTIC 5개년 사업계획의 대요를 살펴보면 ①본 센터 특유의 정보 서어비스ㆍ패턴의 정립, ②대규모 데이터ㆍ뱅크의 설치ㆍ운영 및 ③장비, 자료, 인원확충과 청사증축 등 3대 실천과제를 설정하고 있다. 이 사업이 끝나는 80년대에는 현재의 KORSTIC의 예산상 자립도 20%를 50%선까지 끌어올린 수 있게 되며, 더 나아가 이를 기초한 사업의 계속적인 확장으로 1988년에는 100% 자립하고, 1989년부터는 적자운영을 할 수 있게 한다는 것이다. 이와 같은 계획이 성공적으로 완수되며 본 센터는 그 규모나 서어비스 내용에 있어 선진국 수준까지는 미치니 못할 것이나 개발도상국의 정보 센터로서는 좋은 표본이 될 수 있을 것 같다. 따라서, 직원훈련이나 장비확보 등에 있어서 특정국가나 UN 기구 등의 원조를 받는 수원기관의 입장을 탈피하고 개발도상국들을 지원하는 원조제공기관으로 성장하게 될 것이라 한다. 동 5개년 사업기간중에 추진될 3가지 주요 사업을 그 내용별로 살펴보면 다음과 같다.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.275-282
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• 2011

A recent development of seismic design, which is required among environmentally friendly members, increased the concern on light-weight concrete. Extending around the building, the structural design which is applied for light-weight concrete has been increased. This study therefore evaluates the bending resistance and the shear resistance involved using four specimens that were manufactured and tested. The parameters used in this study exist. This study investigates the structural performance of composite slab using light-weight concrete with KCI (2007).