• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.339-343
• /
• 2015

To rapidly recover ceased functionality of a facility after a catastrophic seismic event, critical decisions on facility repair works are made within a limited period of time. However, prolonged damage assessment of facilities, due to massive damage in the surrounding region and the complicated damage judgment procedures, may impede restoration planning. To assist reliable structural damage estimation without a deep knowledge and rapid interactive analysis among facility damage and restoration operations during the approximate restoration project planning phase, we developed a prototype of distributed facility restoration simulations through the use of high-level architecture (HLA) (IEEE 1516). The simulation prototype, in which three different simulations (including a seismic data retrieval technique, a structural response simulator, and a restoration simulation module) interact with each other, enables immediate damage estimation by promptly detecting earthquake intensity and the restoration operation analysis according to estimated damage. By conducting case simulations and experiments, research outcomes provide key insights into post-disaster restoration planning, including the extent to which facility damage varies according to disaster severity, facility location, and structures. Additional insights arise regarding the extent to which different facility damage patterns impact a project's performance, especially when facility damage is hard to estimate by observation. In particular, an understanding of required type and amount of repair activities (e.g., demolition works, structural reinforcement, frame installation, or finishing works) is expected to support project managers in approximate work scheduling or resource procurement plans.

• 한국염색가공학회지
• /
• 제35권4호
• /
• pp.246-255
• /
• 2023

In this study, we investigated for natural rubber foam to replace petrochemical-based neoprene foam. Experiments were conducted on vulcanization system and 2-step foaming process of natural rubber. The vulcanization system were EV(Efficient Vulcanization Cure), Semi-EV(Semi-Efficient Vulcanization Cure) and CV(Conventional Vulcanization Cure). In the 2-step foaming process, first molding temperature was 140℃, times were 15, 20, 25, and 30minutes, and the second molding temperature was 160℃, the times 5, 10, 15, and 20minutes. The cure and viscosity characterization were evaluated by oscillating disc rheometer (ODR) and mooney viscosmeter. Various mechanical characteristics, including hardness, tensile strength, elongation at the point of rupture, and tear strength, were quantified. Subsequently, an assessment of alterations in these mechanical attributes was conducted post-immersion in a NaCl solution. In addition degree of volume change was measured after immersing the NR foam in NaCl solution and the low-temperature permanent compression set was evaluated at 4℃. And expansion ratio and shrinkage ratio of NR foam were evaluated for 28 days. As a result the EV vulcanization system showed the least change in physical properties before and after salt water immersion, and the lowest shrinkage ratio for 28 days. In addition it was confirmed that the 2-step foaming optimum condition differed depending on the appropriate vulcanization condition.

• 대한치과교정학회지
• /
• 제53권6호
• /
• pp.365-373
• /
• 2023

Objective: To investigate the potential correlation between fixed orthodontic retention failure and several patient- and treatment-related factors. Methods: Patients finishing treatment with fixed appliances between 2016 and 2017 were retrospectively included in this study. Those not showing fixed retention failure were considered as control group. Patients with fixed retention failure were considered as the experimental group. Additionally, patients with failure of fixed retainers in the period of June 2019 to March 2021 were prospectively identified and included in the experimental group. The location of the first retention failure, sex, pretreatment dental occlusion, facial characteristics, posttreatment dental occlusion, treatment approach and presence of oral habits were compared between groups before and after treatment separately by using a Fisher exact test and a Mann-Whitney U test. Results: 206 patients with fixed retention failure were included, 169 in the mandibular and 74 in the maxillary jaws. Significant correlations were observed between retention failure in the mandibular jaws and mandibular arch length discrepancy (P = 0.010), post-treatment growth pattern (P = 0.041), nail biting (P < 0.001) and abnormal tongue function (P = 0.002). Retention failure in the maxillary jaws was more frequent in patients with IPR in the mandibular jaws (P = 0.005) and abnormal tongue function (P = 0.021). Conclusions: This study suggests a correlation between fixed retention failure and parafunctional habits, such as nail biting and abnormal tongue function. Prospective studies with larger study populations could further confirm these results.

• Journal of the Korean Wood Science and Technology
• /
• 제30권4호
• /
• pp.27-32
• /
• 2002

PEG 처리가 고함수율 상태의 방부처리 삼나무 원주가공재의 건조 할렬 방지 및 방부제의 침투성에 미치는 영향을 검토하였다. 농도 10%의 방부제(Basilit CFK) 용액에 1일간 침지 처리한 시험체의 표면에 노도 50%의 PEG-400을 각각 3, 5, 10획 도포하여 30일간 천연 건조한 후 할렬의 발생정도 및 변재부의 방부제 침윤도를 조사하였다. 변재부의 방부제 침윤도를 조사한 결과, 방부제 단독처리 시험체에서는 약 23.2%였으나 방부제 PEG 처리 시험체에서는 약 51.2~64.5%로 비교적 높은 값을 나타내 PEG처리에 의하여 방부제의 침투가 촉진된 것으로 추정되었다. 천연건조 기간 중에 방부제-PEG 처리 시험체에서의 건조 할렬 발생은 PEG 도포횟수의 증가와 함께 뚜렷하게 감소하였을 뿐만 아니라 발생된 몇 개의 할렬의 크기도 방부제 단독처리 시험체에서 발생한 것에 비하여 현저하게 작았다. 그러나 2개월간 옥외 폭로 후에는 방부제-PEG처리 시험체에서 많은 할렬이 발생하여 PEG 처리 효과가 인정되지 않았으나, PEG 처리 후, 폴리우레탄수지 래커로 도장 처리한 결과, 옥외 폭로기간 중에 할렬 발생이 뚜렷하게 방지되었다

• Animal Bioscience
• /
• 제35권3호
• /
• pp.461-474
• /
• 2022

Objective: This experiment investigated the effects of supplementing vitamin D₃-fortified sow and progeny diets with 25(OH)D₃ on growth performance, carcass characteristics, immunity, and pork meat quality. Methods: The present study involved the assessment of supplementing the diet of sows and their progeny with or without 25 (OH)D₃ in a 2×2 factorial arrangement on the performance and production characteristics of wean-finish pigs. Forty-eight multiparous sows were assigned to a basal diet containing 2000 IU/kg vitamin D₃ and supplemented without (CON) or with (TRT) 50 ㎍/kg 25 (OH)D₃. At weaning, a total of 80 pigs each from CON and TRT sows were allocated to weaning and growing-finishing basal diets fortified with 2,500 and 1,750 IU/kg vitamin D₃ respectively and supplemented without or with 50 ㎍/kg 25(OH)D₃. Results: Sows fed 25(OH)D₃-supplemented diets improved pre-weaning growth rate of nursing piglets. A significant sow and pig weaning diet effect was observed for growth rate and feed efficiency (p<0.05) during days 1 to 42 post-weaning. Pigs consuming 25(OH)D₃-supplemented diets gained weight faster (p = 0.016), ate more (p = 0.044) and tended to convert feed to gain more efficiently (p = 0.088) than those fed CON diet between days 98 and 140 post-weaning. Supplemental 25(OH)D₃ improved water holding capacity and reduced drip loss of pork meat, increased serum 25(OH)D₃ level, produced higher interleukin-1 and lower interleukin-6 concentrations in blood circulation, downregulated myostatin (MSTN) and upregulated myogenic differentiation (MYOD) and myogenic factor 5 (MYF5) gene expressions (p<0.05). Conclusion: Supplementing vitamin D₃-fortified sow and wean-finish pig diets with 50 ㎍/kg 25(OH)D₃ significantly improved production performance suggesting their current dietary vitamin D₃ levels are insufficient. In fulfilling the total need for vitamin D, it is strongly recommended to add 50 ㎍/kg 25(OH)D₃ "on top" to practical vitamin D₃-fortified sow and wean-finish pig diets deployed under commercial conditions.

• Radiation Oncology Journal
• /
• 제10권2호
• /
• pp.193-204
• /
• 1992

가톨릭의대 강남성모병원 치료방사선과에서는 1983년 3월부터 1990년 12월까지 74명이 식도암으로 진단되어 방사선치료를 받았다. 이중 6명은 추적소실되었고, 13명은 치료중단되어 55명에 대한 후향적 분석을 했다. 이중 32명은 근치적 방사선치료를 받았고, 12명은 대증적 방사선치료를 받았으며, 10명은 수술후 방사선치료를 받았다. 나머지 1명은 수술 전후로 방사선치료를 실시 했다. 55명중 28명은 방사선치료 단독으로, 27명은 방사선과 약물 병용요법으로 치료했다. 근치적 방사선치료받은 32명중 88%의 환자에서 관해를 얻었으며, 이중 완전관해는 19%, 부분관해는 69%였다. 전체 환자의 평균생존기간과 2년 생존율은 15.6개월과 22%였다. 성별, 나이, 병리학적 분화도, 종양위치, 크기, 병기, 방사선치료목적, 관해정도, 방사선 치료선량, 약물요법 병용유무, 치료시작시와 치료종결시의 연하곤란정도가 생존율에 미치는 영향을 조사했다. 이중 종양의 크기, 병기, 관해정도가 가장 큰 예후인자였으며 특이한 점은 수술후 방사선치료의 평균생존기간과 2년 생존율은 24.7개월과 63%로 근치적 방사선치료후 완전관해를 얻었을 때의 평균생존기간과 2년 생존율 29.1개월과 43%에 유사한 좋은 결과를 보여 줬다. 이는 아마도 수술받은 환자의 선별된 선택에 기인한 것으로 생각되고, 또한 연하곤란의 정도는 치료시작 때보다 치료종결시의 연하곤란정도가 예후에 약간의 영향을주었다. 또한 근치적 방사선 치료의 경우 60 Gy이상 줬을 때가 그 이하로 치료했을 때보다 좋은 생존율을 얻었으나 통계적 의의는 없었다. 대증적 방사선치료의 경우, 75%에서 연하곤란의 개선을 보였고, 평균지속기간은 10.6개월이었다.

• 한국건설관리학회논문집
• /
• 제17권3호
• /
• pp.125-133
• /
• 2016

프로젝트 리스크관리는 프로젝트 착수에서 완공에 이르기까지 프로젝트 생애주기 동안 프로젝트의 범위, 비용, 일정 등에 영향을 미치는 위협 및 기회 요인을 포함하는 리스크를 사전에 식별하고 이에 대한 완화전략을 사전에 마련함으로서 프로젝트를 성공에 이르게 하는 효과적인 관리를 위해 활용된다. 프로젝트를 진행하는데 있어서 완공일이 지나기 전에 예산과 공사기간을 정확히 예측하는 것은 불가능하므로, 미국 워싱턴교통부에서는 사업비 규모에 따라 여러 분야의 전문가를 참여자로 하는 워크숍을 실시하게 함으로서 체계적인 리스크관리를 의무화하고 있다. 하지만 국내 건설 현장에서는 체크리스트 및 리스크분석 위주의 리스크관리만 이루어지고 있어 효율적인 관리가 이루어지지 않고 있다. 따라서 본 연구에서는 국내 A하천정비사업에 워크숍 기반 리스크관리기법을 국내 처음으로 적용해 봄으로서 국내 현실에 적합한 효율적인 리스크관리 방법을 제안하였다. 또한 이러한 리스크관리 전 과정에 식별된 리스크를 분석하여 완화전 후의 리스크에 대한 비교를 쉽게 살펴보고 관리할 수 있는 RBES 프로그램을 활용하였다. 그 결과 전체 사업비용과 공사기간의 증가 문제를 사전에 인지하고 이에 대한 실질적인 완화대책을 수립하게 함으로서 공사기간 지연효과를 미리 방지하는 효과가 있었다.

• The Journal of Advanced Prosthodontics
• /
• 제7권1호
• /
• pp.56-61
• /
• 2015

PURPOSE. The purpose of this study was to evaluate the effects of the surface treatment and shape of the dental alloy on the composition of the prosthetic work and its metallic ion release in a corrosive medium after casting. MATERIALS AND METHODS. Orion Argos (Pd-Ag) and Orion Vesta (Pd-Cu) were used to cast two crowns and two disks. One of each was polished while the other was not. Two as-received alloys were also studied making a total of 5 specimens per alloy type. The specimens were submersed for 7 days in a lactic acid/sodium chloride solution (ISO standard 10271) and evaluated for surface structure characterization using SEM/EDAX. The solutions were quantitatively analysed for the presence of metal ions using ICP-MS and the results were statistically analysed with one-way ANOVA and a Tukey post-hoc test. RESULTS. Palladium is released from all specimens studied (range $0.06-7.08{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$), with the Pd-Cu alloy releasing the highest amounts. For both types of alloys, ion release of both disk and crown pairs were statistically different from the as-received alloy except for the Pd-Ag polished crown (P>.05). For both alloy type, disk-shaped pairs and unpolished specimens released the highest amounts of Pd ions (range $0.34-7.08{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$). Interestingly, in solutions submerged with cast alloys trace amounts of unexpected elements were measured. CONCLUSION. Shape and surface treatment influence ion release from dental alloys; polishing is a determinant factor. The release rate of cast and polished Pd alloys is between $0.06-0.69{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$, which is close to or exceeding the EU Nickel Directive 94/27/EC compensated for the molecular mass of Pd ($0.4{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$). The composition of the alloy does not represent the element release, therefore we recommend manufacturers to report element release after ISO standard corrosion tests beside the original composition.

• 한국농촌건축학회논문집
• /
• 제16권1호
• /
• pp.119-127
• /
• 2014

This study suggests institutional and methodological approaches for preservation of South Korea's registered cultural properties of modern architecture. The suggested approaches are as follows. First, in order to improve the current registration and preservation system for cultural properties, we need to employ both structure-based classification and style-based classification. Registration criteria for modern architecture properties need to include more detailed classification in terms of their structure: brick structure, steel concrete structure and post lintel structure. In terms of construction style, the properties need to be further classified into the western style, the traditional style and the Korean-western eclectic style. In addition, protection of registered cultural properties need to be achieved through legislation of a protection system. Second, while the current system sets out six methods for preservation of registered cultural properties of modern architecture, more specific preservation methods types and plans need to be continuously introduced. In particular, as for the method of partial preservation, the method needs to be further classified based on the usage of the relevant structure so as to allow for more diverse options. First, the 'Preservation by Interior Alteration' needs to be added to the category, where the exterior is preserved as it is and the interior is preserved through alteration. Also needs to be added the preservation method where the interior space is preserved as it is and the exterior space is altered, in case the finishing materials of the exterior has deteriorated. Third, if the records on registered cultural properties of modern architecture are to provide the functions of legal evidences regarding management of architectural cultural properties, sources of knowledge required for policy making and implementation and past management record for the future, each phase needs to be closely connected in an organic manner, and we need to establish a management system and plan that go beyond the relevant organizations. Fourth, in order to preserve South Korea's registered cultural properties of modern architecture in its original state, it is imperative to prepare separate criteria for registration of technicians with expertise on modern architecture, and train experts and technicians on modern architecture, which is distinguished from the traditional architecture.

• 한국응급구조학회지
• /
• 제18권1호
• /
• pp.83-94
• /
• 2014

연구 목적 : 우리나라는 인도주의적 차원에서 국제구조대와 한국재난대응팀을 파견하고 있으며 이는 공적개발원조의 하나인 해외긴급구호활동에 해당하는 것으로 주로 소방대원과 의료인들이 활동하고 있다. 따라서 이 연구는 글로벌 재난 역량 개발 프로그램이 응급구조과와 간호학과 학생들에게 어떠한 영향을 미쳤는지 살펴보고 이를 통해서 추후 학부교육에 대한 개선방안을 모색하고자 한다. 연구 방법 : 본 프로그램은 ICN에서 제시한 "재난간호역량체계"를 기본 틀로 4개 영역 10개 도메인으로 역량을 구분하여 프로그램을 설계하였다. 프로그램은 2013년 8월 12일부터 23일까지 2주간 사례학습, 토론, 전문가 특강, 태국 카렌지역 현지방문 등 다양한 방식으로 운영되었으며 참석학생은 총 18명이었다. 프로그램에 대한 만족도는 5점 척도로 측정하였고, 국제재난역량 지식수준은 10점 척도로 측정하여 프로그램 전후 지식수준을 비교분석하였다. 그 외 심층 인터뷰를 진행하여 재난에 대한 학생들의 태도 변화를 보았다. 연구 결과 : 프로그램 만족도는 $4.50{\pm}0.51$로 매우 높았으며 국제재난관련 지식의 변화는 전체 항목 평균 $2.18{\pm}0.68$에서 $6.30{\pm}0.84$로 상승하였다(p <.001). 그 외 프로그램의 신청 동기는 다중응답으로 다양한 경험을 쌓기 원해서(14명), 해외봉사에 대한 관심(11명), 국제기구에 대한 관심(7명) 등으로 조사되었다. 결 론 : 첫째, 응급구조과와 간호학과 학부 교육과정에서 국제재난에 대한 이해를 증진할 수 있는 교과목이 개설되거나 기존의 유사한 과목에서 글로벌 환경에 대한 조기 이해가 선행되도록 하여 국제사회에 진출하고자 하는 학생들에게 다양한 진로를 제시해 주어야 한다. 둘째, 국제재난관리에 대한 교육은 학습효과를 증진하기 위해서 시물레이션 학습 또는 재난현장을 방문한 현장학습 등 다양한 방법의 적용이 고려되어야 국제사회 및 문화에 대한 이해도모와 태도변화 그리고 어학 학습의 중요성을 자각하게 할 수 있다. 셋째, 학부 단계에서 국제재난교육을 통해서 이해를 도모하고 진로와 관련한 다양한 정보습득 및 참여기회가 증진되도록 하여 졸업 후 실무에 적용이 가능하도록 교육하는 것이 필요하다.