• 한국압력기기공학회 논문집
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• 제16권2호
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• pp.10-17
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• 2020

Securing the integrity of steam generator tubes is an essential requirement for safe operation of nuclear power plants. Therefore, tubes that do not satisfy integrity requirements are no longer usable and must be repaired according to the related requirements. In general, the repair criterion is that the damage depth is more than 40% of the tube wall thickness. However, the plugging limit can be changed and be applied, provided a technical proof is given that integrity can be secured against specific degradation at a specific plants and that approval can be obtained from a regulatory agency. A typical example is alternative repair criteria for defects within the tube sheet or tube support plates. In this paper, a background of establishing the plugging limit for steam generator tubes and changes in maintenance criteria are reviewed as examples.

• 한국건축시공학회지
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• 제11권6호
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• pp.597-608
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• 2011

공동주택의 건설 분쟁(Claim)발생 시 지속적으로 발생하는 하자의 보수비용 산정 방안에 대한 객관적 기준이 없어 건설전문가들도 각자의 경험과 성향에 따라 다양하게 판단하게 되므로 문제점을 발생 시키고 있다. 따라서 본 연구에서는 이에 대한 분석을 통하여 보수비용 산정기준과 방안을 제시한 후 건축물 하자관련 담당자들에게 합리적인 하자 판단기준을 제안 하고자 한다. 연구결과, 실적공사비를 우선 적용하며 실적공사비에 없는 항목은 표준품셈을 활용하여 산정한다. 지속형 하자 유형인 법규위반 하자의 보수비용 산정은 위반 건물부위만 철거하여 재시공하는 비용을 산정하고, 진행성(확대)하자는 건물 준공의 경과연수에 비례하여 기여율로 산정하며, 반복성 하자는 하자를 최소화시키는 방법의 설비공법을 대안으로 강구하여 산정하고, 가치감소 하자는 내용연수대비 하자보증기간의 비율로 산정하는 방법을 제안하였다. 이중 가치감소하자 보수비용의 산정은 향후 보다 많은 연구가 필요할 것으로 사료된다.

• 한국안전학회지
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• 제30권4호
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• pp.168-173
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• 2015

A steam generator tubing is one of the main pressure boundary of the reactor coolant system in the nuclear power plants. Structural integrity refers to maintaining adequate margins against failure of the tubing. Burst pressure of a tube at tube support plate can be higher than that for a free-span tube because failure behaviors could be interfered from the tube support plate. Alternative repair criteria for out-diameter stress corrosion cracking indications in tubes to the drilled type tube support plate were developed, however, there are very limited information to the eggcrate type tube support plate. This paper discussed reinforcement effect of steam generator tube burst pressure with axial out-diameter stress corrosion cracking within an eggcrate type tube support plate. A series of tube burst tests were performed under the room temperature and it was found out that there is no significant but marginal effects.

• 토지주택연구
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• 제5권4호
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• pp.297-303
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• 2014

최근, 공동주택 단지내 투수성 포장 및 블록포장 등과 같은 포장이 많이 시공되고 있으나 품질관리와 공용성 평가에 관한 기준이 미비하여 하자 교체 및 교체주기 시기 결정 등에 어려움이 많은 실정이다. 따라서, 본 연구에서는 공동주택에 많이 적용되고 있는 투수성포장 및 블록 포장의 합리적 선정기준을 제안하기 위해 교체주기, 초기 공사비, 유지교체비용 등을 고려한 포장공법별 생애주기 비용 분석(LCCA)을 실시하였다. 생애주기비용 분석결과는 교체주기 20년이상인 인터록킹 콘크리트 블록포장이 최적의 대안이지만, 보도 포장의 교체기준 10년을 기준으로 하였을 경우 최적의 대안은 일반적인 아스팔트 콘크리트 포장임을 알 수가 있다. 따라서, 교체주기가 대안의 선정 및 생애주기비용 분석에 많은 영향을 미치므로 향후, 교체주기의 객관적인 정량화에 필수적인 공용성 지수 개발이 필요하다.

• 한국주거학회논문집
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• 제20권6호
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• pp.57-65
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• 2009

In Korea, Housing Performance Rating Indication System was first adopted in 2006. Main purpose of the System is on developing criteria which can systematically measure the level of housing performance. Among the five categories of Housing Performance Rating Indication System, Repair Convenience is closely related to Remodeling which has been widely recognized as an alternative to the building reconstruction. Especially, as the actual housing supply level in Korea is reaching almost 100%, it is crucial to expand Long-life Housing through the effective maintenance and management. In addition, consumers should have an access to the performance ratings of apartment buildings on which they can rely on in choosing their own housings. And for construction companies, a performance code enacted by government will provide them with a standard that they can utilize in determining performance level of buildings that they build. This study examines data which has been obtained from the recent application of Housing Performance Rating Indication System and Repair Convenience category is main concern. Findings from the study will provide vital information in improving current Housing Performance Rating Indication System.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.965-968
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• 2008

본 연구는 보수재료의 다양한 요구성능 중 정성적 측면을 고려하여 최적의 보수재료를 선정하기위한 평가모델을 구축하고자 하였다. 다양한 보수 대안에 대한 평가모델을 구축하기위해서 본여구에서는 위계분석기법(AHP)가 적용되었다. 평가모델의 평가항목에는 미적성능, 환경성, 작업성, 경제성으로 크게 분류되었으며, 미적성능은 마감성과 변동성, 작업성은 품질관리난이, 구성재료수, 시공성으로, 경제성은 시공비용, 보수공기, 소요장비의 항목으로 세분되어 구성되었다. AHP기법의 상대적 평가방법에 따라서 각 평가항목별 쌍대비교를 한 결과, 환경성과 시공비용이 가장 가중치가 높은 중요한 평가항목으로 산정되었다. 본 연구에서 제시한 정성적 평가항목에 대한 평가모델은 다양한 보수대안 중에서 정성적 평가항목을 고려하여 최적의 보수대안을 선정할 때 매우 유용하게 활용될 수 있다.

• 한국주거학회논문집
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• 제20권6호
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• pp.47-56
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• 2009

Housing Performance Rating Indication System was started in 2006. The aim of Housing Performance Rating Indication is to provide the guideline of housing performance. Repair Convenience is similar to Remodeling. Remodeling has been paid more attention as an alternative for reconstruction. Especially, now the actual house supply is facing almost 100%, it is time to keep and maintenance management of apartment buildings, and ultimately it will expand the Long life housing. Especially consumers has to have a right to select apartment buildings by comparing performance of house. For construction companies, they need a performance code that standardized by government, so they can provide a Certain performing house. This study examines data which has been obtained from the recent application of Housing Performance Rating Indication System and Repair Convenience category is main concern. Findings from the study will provide vital information in improving current Housing Performance Rating Indication System.

• Clinics in Shoulder and Elbow
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• 제26권3호
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• pp.296-301
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• 2023

Background: A supervised physiotherapy program (SPP) is a standard regimen after surgical rotator cuff repair (RCR); however, the effect of a home-based exercise program (HEP), as an alternative, on postoperative functional recovery remains unclear. Therefore, the purpose of this meta-analysis was to compare the functional effects of SPP and HEP after RCR. Methods: We searched electronic databases including Central, Medline, and Embase in April 2022. The primary outcomes included the Constant score, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and pain score. Secondary outcomes included range of motion, muscle strength, retear rate, and patient satisfaction rate. A meta-analysis using random-effects models was performed on the pooled results to determine the significance. Results: The initial database search yielded 848 records, five of which met our criteria. Variables at 3 months after surgery were successfully analyzed, including the Constant score (mean difference, -8.51 points; 95% confidence interval [CI], -32.72 to 15.69; P=0.49) and pain score (mean difference, 0.02 cm; 95% CI, -2.29 to 2.33; P=0.99). There were no significant differences between the SPP and HEP. Other variables were not analyzed owing to the lack of data. Conclusions: Our data showed no significant differences between SSP and HEP with regard to the Constant and pain scores at 3 months after RCR. These results suggest that HEP may be an alternative regimen after RCR. Level of evidence: I.

• 한국도로학회논문집
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• 제17권3호
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• pp.85-95
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• 2015

PURPOSES : Recently, bonded concrete overlay has been used as an alternative solution in concrete pavement rehabilitation since its material properties are similar to those of the existing concrete pavements. Deteriorated concrete pavements need rapid rehabilitation in order to prevent traffic jams on Korean expressways. Moreover, speedy and effective repair methods are required. Therefore, the use of bonded concrete overlay with ultra-rapid hardening cement has increased in an effort to reopen promptly the expressways in Korea. However, mobile mixer is required for ultra-rapid hardening cement concrete mixing in the construction site. The use of mobile mixer causes various disadvantages aforementioned such as limitation of the construction supply, open-air storage of mixing materials, increase in construction cost, and etc. In this study, therefore, hydration accelerator in-situ mixing on polymer modified concrete produced in concrete plant is attempted in order to avoid the disadvantages of existing bonded concrete overlay method using ultra-rapid hardening cement. METHODS : Bonded concrete overlay materials using ultra-rapid hardening cement should be meet all the requirements including structural characteristics, compatibility, durability for field application. Therefore, This study aimed to evaluate the application of hydration accelerator in-situ mixing on polymer modified concrete by evaluating structural characteristics, compatibility, durability and economic efficiency for bonded concrete overlay. RESULTS : Test results of structural characteristics showed that the compressive, flexural strength and bond strength were exceed 21MPa, 3.15MPa and 1.4MPa, respectively, which are the target strengths of four hours age for the purpose of prompt traffic reopening. In addition, tests of compatibility, such as drying shrinkage, coefficient of thermal expansion and modulus of elasticity, and durability (chloride ions penetration resistance, freezing-thawing resistance, scaling resistance, abrasion resistance and crack resistance), showed that the hydration accelerator in-situ mixing on polymer modified concrete were satisfied the required criteria. CONCLUSIONS : It was known that the hydration accelerator in-situ mixing on polymer modified concrete overlay method was applicable for bonded concrete overlay and was a good alternative method to substitute the existing bonded concrete overlay method since structural characteristics, compatibility, durability were satisfied the criteria and its economic efficiency was excellent compare to the existing bonded concrete overlay methods.

• Journal of Chest Surgery
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• 제32권7호
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• pp.628-636
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• 1999

배경: 최근에 완전방실중격결손의 해부학적 구조에 대한 이해가 증가됨에 따라서 본원에서는 수술방법에 있 어서 여러 가지 변형을 시도하게 되었다. 대상 및 방법: 1997년 5월부터 1998년 7월까지 8명의 완전방실중 격결손 환자를 수술하였다. 남녀 각각 3명, 5명이었으며 나이는 2개월에서 28개월까지 분포하였고 평균 몸무 게는 6.0$\pm$2.2 Kg이었다. 심장의 해부학적 구조에 따라서 3명의 환아에서는 심실중격결손을 일차적으로 봉합 하여 수술을 단순화하였다(Group I). 좌심실유출로 협착의 가능성이 있는 2명의 경우에는 통상적인 방법대로 2개의 포편을 이용하였다(Group II). 그리고 불균형 완전방실중격결손의 경우에는 심실중격결손을 막는 포편 을 우심실에 치우쳐서 막고 심방중격을 새로 만들거나 좌측 방실판막의 부족한 판막부위를 자가 심낭막으로 메꾸어 주거나 좌측 방실판막이 parachute valve 인 경우에는 2개의 판막입구를 만들어 주었다(Group III). 결과: 모든 환자가 수술후 만족스러운 혈류역학을 보였으며 7명에서는 평균 3$\pm$1 일만에 인공호흡기 이탈이 가능하였으며 1명의 환자는 심장의 문제없이 폐질환으로 24일만에 인공호흡기를 이탈하였다. 수술후 합병증 으로 III군에서 판막성형을 시행한 좌측 판막이 찢어지면서 판막역류가 점진적으로 심해진 1명에서 2주만에 재수술을 하였다. 조기 및 만기사망은 없었으며 수술후 심장초음파검사에서 약간의 좌측 방실판막협착이 III 군에서 1명 있었으며(평균압력차 6.5 mmHg), 좌측 방실판막역류가 7명(87.5 %)의 환아에서 Grade I 이하였으 며, 우측 방실판막역류는 모든 환아에서 Grade I 이하였다. 결론: 완전방실중격결손의 수술시 해부학적인 구 조에 따라서 선택적으로 일부 환아에서는 심실중격결손을 일차적으로 봉합함으로써 수술을 단순화할 수 있 으며 우심실이 발달된 불균형 완전방실중격결손에서도 변형수술방법을 통하여 양심실성 교정을 하여 좋은 결과를 얻을 수 있었다.