• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.99-106
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• 2007

To satisfy with the increased requirements of cost reduction, labor saving, and rapid construction, the purpose of this study is to investigate the structural behavior of PSC monolithic and spliced girders. Three tests were conducted on small-scale girder specimens. This paper presents the result of experimental studies in terms of the load-deflection behavior. Different joint type and tendon amount were investigated as major variables. The monolithic girder was arranged with three tendons. The spliced girder consisted of five segments connected by three tendons. In addition, five-segmented girders connected by more than three tendons were built to examine the effect of the tendon amount. The experimental results show the difference of behavior between monolithic and spliced girders. Moreover, nonlinear finite element method analysis was utilized to verify the experimental result.

• Journal of Korean Society of Steel Construction
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• v.20 no.5
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• pp.609-616
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• 2008

Recently, many ocean bridges that connect land to island or island to island have been constructed along with the improvement of the nation's economy. Long-span bridges can be categorized as suspension bridge, cable-stayed bridge, arch bridge and truss bridge. In this study, correction with respect to construction error can be presented on site through the monitoring of the cable tension change of real structure for four major construction stages so that construction accuracy, including the management of profiles, can be improved. A vibration method, the so-called indirect method that uses the cable's natural frequency changes from the acceleration sensor installed on the cable, is applied in measuring cable tension. In this study, the estimation formula for the effective length of cable with damper is presented by comparing and analyzing between actual measurement and analysis result for the change of the cable's effective length. By the way, it is known that the reliability of estimating cable tension by applying the former method that uses the net distance from damper to anchorage is low. Therefore, for future reference of the maintenance stage, the presented formula for estimating the effective length of cable can be used as a reference for the rational decision-making, such as the re-tensioning and replacement of cable.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.347-355
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• 2021

During the earthquake, for multi-story structure, if the first floor is soft, the deformation will concentrate on that floor causing a serious damage to the column members which might leads to the collapse of the whole structure like Piloti structure during the Pohang earthquake in Korea. According to the 2016 National Disaster Management Research Institute's "Investigation of Seismic Reinforcement and Cost Analysis of Domestic Non-seismic Buildings", the rate of seismic resistance of private reinforced concrete buildings was 38.3 %. Among them, it was reported that the seismic-resistance ratio of the two to five-story structures was less than 50 %. Accordingly, the government is trying to improve the seismic rate through support projects, but the conventional seismic reinforcement methods are still expensive, and emergency construction is difficult. Therefore, in this study, the field applicability was evaluated by improving the reinforcement method using Velcro, which was developed through the research project of the Ministry of Land, Transport and Maritime Affairs in 2014. In order to improve the performance of the Velcro reinforcement method, introducing the initial tension of Velcro using high foaming rigid urethane filling between the Velcro and concrete of the columns was applied. Additionally, an experiment was conducted to evaluate the ductility of Velcro specimen from the concrete confinement effect. As a result, the ductility of the Velcro specimen was improved compare to Normal specimen. However, the energy dissipation capacity of VELCRO2 is better than VELCRO1, yet the maximum ductility of those two specimens did not show a significant difference. Therefore, the improvement of the internal filler material is still needed to have a better maximum ductility.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.72-85
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• 2009

This study attempts to examine the principles of landscape composition for a 'Suhwon(書院)' and the meaning and value of its traditional landscape architecture, in order to apply the results to the design of modern landscape architecture. A 'Suhwon' is a vital space containing the form and meaning of human activity. This study analyzes the characteristics of landscape composition in the construction of the Namgea Suhwon, located in Hamyang, by examining the form and meaning of its area and composition. The Namgea Suhwon was constructed with a suitable configuration and harmony in a good location, neither field nor mountain, and which encompasses transcendence and a return after passage through a period of birth and abundance. Its appearance means 'life existence and hidden death(生居死幽)'. Its spatial system is a reflection of the idea of Samshinoje(三神五帝: The three abilities of Providence and its five subjects) connected with Ilsangje -Samshin -Ohje. It was built based on the idea of Biryebudong(非禮不動) meaning that one should follow only good decorum and avoid discourtesy, complying with "the frame of decorum" developed by the family rites of Chu Hsi. The environmental design of the Namgea Suhwon was interrupted by the material confrontation between mountains and water and a binary code system, such as front to rear, length to breadth, and movement to stillness. The design did not adhere to stiff axes, but pursued the harmonic principles of asymmetric balance in the building and the yard, which are very naturalistic. The name 'Namgea Suhwon' is closely related with the view of placement(置) and harmony(和), which are unified with the function and meaning formed by connecting Sung Confucianism with the Pungsu-Sasinsa structure in the layout of the grounds. When examining the D/H ratio of the building and yard, it can be seen that the spaces of Ganghak, Yusang and Jehyang were built appropriately, according to the natural characteristics of each space, such as a sense of openness, enclosure, tension, relief, enhancement, and hierarchical order. The spaces also reflect human scale concepts that take advantage of auditory features. The transition process after the construction of 'Namgea Suhwon' reveals the intentions of the builder to create an ecological landscape composition based on Placement and Harmony. Placement embodies' a purposeful space in which nature and the building are connected naturally, 'incomplete open space pursuing completion', and 'potential beauty in which tension and relaxation are repeated'. Harmony embodies 'order and continuity having a sense of unity with the natural environment' and the 'sharing of daily life and memory'. 'Namgea Suhwon' contains many ideas for landscape planning, land use and the design of a campus environment.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.107-113
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• 2012

Purpose: The purpose of this study was to evaluate the posterior cruciate ligament (PCL) reconstruction with single bundle, single-incision technique using Achilles tendon and tibialis anterior allograft with ligament remnant preservation. Materials and Methods: Twenty six patients underwent PCL reconstruction was included. There were 21 males and 5 females. Mean age was 32 years. Used graft was a fresh frozen Achilles tendon allograft (group I, 14 cases) and tibialis anterior allograft (group II, 12 cases). Arthroscopic PCL reconstruction was performed using transtibial, single-incision and single bundle technique with remnant preserving as possible. For clinical evaluation, range of motion, posterior drawer test, Lysholm score, Tegner activity scale, International Knee Documentation Committee (IKDC) grade and posterior stress radiograph were used. The mean follow-up period was 21.6 months (12-40 months). Associated injuries were 5 medial collateral ligament injuries, which were treated by conservative method. Results: Range of motion (ROM) was returned to normal range in 24 cases, but ROM deficit under $10^{\circ}$ flexion was 2 cases at final follow-up period. Preoperative posterior drawer test was 17 cases in grade II and 9 cases in grade III. At final follow-up 13 cases returned within normal grade, 7 cases grade I and 6 cases grade II posterior instability. Lysholm mean score was improved from preoperatively 62 to 90 at final follow-up period. Tegner activity mean scale improved from preoperatively 3.5 to 5.6 at final follow-up period. IDKC grade was grade A was 3 cases, grade B 17 cases, grade C 6 cases. In posterior stress radiograph, posterior displacement was improved from mean 12 mm preoperative to 4.5 mm at final follow-up. There were no statistical differences between two groups in clinical evaluations. There were two cases of re-rupture of graft at the bone-tendon junction in group I. Conclusion: We had successful results of PCL reconstruction with single-incision, single bundle technique using Achilles and tibialis anterior allograft without difference between two groups in patients with PCL injury. There were more re-rupture of graft in Achilles tendon group.

• Journal of International Area Studies (JIAS)
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• v.22 no.2
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• pp.217-244
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• 2018

As Chinese insurance market grows rapidly due to market reforms, China got recognition as second-largest insurance market in the world in 2016. However Korean insurance companies have had difficulties to grow in Chinese insurance market despite Chinese participation in the World Trade Organization (WTO) and the growth of chinese insurance market. The reason for the decline in Korean insurance companies is economic retaliation due to the deployment of THAAD in Korea. However, this is not a fundamental reason. The underlying cause of the effects of economic retaliation is the result of insufficient negotiations in Korea-China FTA services sector. In Service sector of Korea-China FTA, the level of concession between Korea and China differs greatly, when comparing China and South Korea's FTA. In addition, it has only been a few years since China collected the position of the WTO Doha Agenda, which currently deals with concessions on intellectual property rights and services. More important is that the Korea-China FTA service sector, as it stopped short of being protected by the most-favored-nation state treatment level when Korean insurance companies entered China. Further negotiations to supplement the weak points in the Korea-China FTA service sector were promised in December 2017, but international tensions over THAAD deployment made it impossible to hold such negotiations. However, due to changes in international affairs in 2018, the first additional negotiation was decided and held. This paper implicates strategies of further negotiation between Korea and China for service and investment chapter. Consequently, the aim of this paper suggests directions how to re-enter Chinese insurance market to Korean insurance companies.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.727-735
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• 2012

Recently, a high-strength strand of 2400 MPa was developed using domestic technologies. In 2011, KS D 7002 was revised to cover the newly developed high-strength strands to support their practical usage. Presently, however, discussions and evaluations are not sufficient on the mechanical properties of the strands and their performance in structural members. Also, there were no detailed reviews on the need to revise the current design code for practical use of the high-strength strands. In this study, flexural behavior of a member with the high-strength strands was estimated through sectional analysis and a review and comparison of the domestic and foreign design codes were conducted considering the analysis results. Also, the need for the revision of the design code was discussed. Such discussion especially focused on the estimation of the stress in strand, which related with various issues such as determination methods for yield point of strands, time-dependent loss of prestressing force, estimation of stress in strand at member failure, and net strain limit for ductile failure of member. The discussion revealed that some parts in the design code need a revision and the further studies are required.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.1
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• pp.28-34
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• 2010

Purpose: The aim of this study was to evaluate short-term clinical results and second-look arthroscopic findings after double-bundle anterior cruciate ligament (DB ACL) reconstruction. Materials and Methods: Forty-nine patients, who were followed up for at least 24 months after DB ACL reconstruction, were included. Clinical results, such as, Lysholm knee and Tegner activity scores, and manual laxity and instrumented anterior laxity test results were evaluated. In fifteen patients (15 knees), second-look arthroscopy with staple removal was performed. At second-look arthroscopy, the authors assessed about reconstructed ACL rupture, subjective graft tension and extent of synovial coverage. Results: Lysholm knee scores significantly improved from 67.4 preoperatively to 96.1 at last follow-up (p<0.01). Tegner activity scale improved from 2.0 to 6.1. The Lachman test, at last follow-up, showed normal laxity in 39 (of 49) patients, and the pivot-shift test showed normal laxity in 36 (of 49) patients. Mean side-to-side differences improved significantly from 10.8 mm to 3.3 mm (p<0.01). Second-look arthroscopic findings showed that all patients had a normal or a near normal anteromedial bundle. However, 8 patients (53.3%) were found to have partial or complete posterolateral bundle rupture. Conclusion: Even though double-bundle ACL reconstruction was clinically effective means of restoring knee rotational and anteroposterior stabilities, there were some ruptured posterolateral bundles observed in cases under arthroscopy after double-bundle ACL reconstruction.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.11-14
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• 2014

This is a retrospective study describing postoperative complication encountered with surgery performed in dogs with medial patellar luxation (MPL). During the 4-year period, 77 operations had been performed in 66 dogs for correction of MPL. The patients were surgically treated with medial soft tissue release, lateral soft tissue tightening, trochlear block recession, and/or tibial tuberosity transposition (TTT). Their prognoses were periodically evaluated for 6 months postoperatively. The failure rate was higher in revision surgery than in the first surgery, and the most common postoperative complication was migration of the tibial tuberosity fragment. The causes for the migration of the tibial tuberosity fragment were identified as the downward insertion of a surgical pin, the eccentric position of an inserted pin in the tibial tuberosity fragment, and blunt angle formation of the tibial tuberosity. It is suggested that the appropriate methods for TTT could minimize complications and lead to a good prognosis.

• Strategy21
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• s.37
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• pp.242-274
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• 2015

2015년 5월 수중발사 탄도미사일(SLBM) 발사시험을 통해 북한은 전 세계의 이목을 또 다시 집중시켰다. 북한은 2013년 제3차 핵실험을 감행한 이후 최근까지도 탄도미사일과 로켓 발사 등의 무력도발을 지속해 왔다. 이와 같은 북한의 무력도발은 한반도의 안정뿐만 아니라 미국 본토의 안보에도 매우 부정적인 영향을 미치고 있다. 지금까지 미국은 북한의 핵미사일 개발 저지를 위해 경제적 또는 군사적 방안들을 선별적으로 적용해 왔다. 그러나, 이러한 미국의 노력에도 불구하고 북한은 여전히 핵미사일을 개발하겠다는 꿈을 포기하지 않고 있는 것이 사실이다. 본 논문은 북한의 핵미사일 개발에 대한 미국의 대안적 전략(Alternative Strategy)을 제시하는데 그 목적이 있다. 필자는 대안적 전략 제시에 앞서 북한의 핵과 탄도미사일 개발현황을 내용(Contents)과 맥락(Context) 차원에서 분석하고 미 오바마 행정부의 대북전략을 비판적으로 검토하였다. 그리고 대안적 전략으로 동맹국과 함께 경제적(Sticky Power), 군사적(Sharp Power) 수단의 동기화(Synchronizing)를 통해 북한이 감당하기 힘든 전략적 환경을 조성(Shaping the Strategic Environment)하는 것이 '북한의 핵개발 포기' 라는 전략목표를 달성하는 방안 임을 강조하고 있다. 미국이 대안적 전략목표를 달성하기 위해서는 경제적 수단으로 ① 북한의 자금세탁 및 위조지폐 발행국 지정, ② 북한을 지원하는 모든 해외자산에 대한 제재조치, ③ 북한의 테러지원국 재지정, ④ 북한 제재를 위한 미국의 입법추진, ⑤ 대량살상무기 관련 금수품목의 확대를 적용함과 동시에 군사적 수단으로 ① 대량살상무기 비확산 활동 강화, ② 대탄도미사일 전략 개발 및 정보(ISR: Intelligence Surveillance and Reconnaissance) 공유, 맞춤형 억제전략(TDS: Tailored Deterrence Strategy)의 구체화 등을 통한 한·미 군사 억제방안의 강화, 그리고 ③ SM-3, THAAD(Terminal High Altitude Area Defense) 등 한·미·일 3자간 MD(Missile Defense)체제의 구축 등을 동기화하여 적용해야만 할 것이다. 미국의 대안적 전략은 ① 북한의 핵미사일 개발에 대한 중국의 협력방지, ② 한·중간 경제관계의 악화, ③ 한·일간의 역사적 긴장관계라는 위험요소를 내포하고 있는 것 또한 사실이다. 따라서 미국이 대안적 전략목표인 '북한의 비핵화' 달성을 위해서는 이와 같은 위험요소를 완화시키는 노력도 병행되어야 할 것이다. 끝으로, 미국은 북한의 김정은이 핵미사일 개발 포기라는 상이한 방향의 전략적 결정을 할 경우에 대비하여 한·미 연합훈련의 보류, 북한에 대한 경제제재조치 해제 등 북한과의 협상 가능성도 열어두고 이에 대해서도 철저하게 준비해 나가야 할 것이다.