Critical items (CI) 尺度의 妥當度 硏究 : Critical items (CI) 척도의 타당도 연구

김재환 부산의대 1981 부산의대잡지 - 부산대학교 의과대학 Vol.21 No.2

Effect of Aluminizing Treatment on the Oxidation Properties of 12Cr Heat Resisting Steel

김재환,왕제필,강창룡 대한금속·재료학회 2011 METALS AND MATERIALS International Vol.17 No.6

In order to investigate the effect of aluminization on the oxidation properties of 12Cr martensitic heat resisting steel, a specimen was prepared by forging after centrifugal casting. After aluminizing treatment under various conditions, scanning electron microscopy observation, and hardness, line profile and x-ray diffraction analysis of the alloy layer were performed. The results confirmed that the thickness of the layer of Al13Fe4, with a Vickers hardness of over 880, increased with increasing aluminizing temperature and time. Moreover, it was concluded from the results of the oxidation experiment that the oxidation properties of the aluminized specimen were improved by up to approximately 30 %.

농촌 진흥법 개정

김재환 한국농촌지도학회 1994 농촌지도와 개발 Vol.1 No.2

전신마취하 복식 전자궁적출술 환자에서 경막외 차단이 신장 기능에 미치는 영향

김재환,장문석,박영철,김지연 대한마취과학회 2000 Korean Journal of Anesthesiology Vol.38 No.2

Background : There are many documents about the hemodynamic changes during sympathetic blockade produced by epidural anesthesia, but few reports have addressed the effects of epidural anesthesia on renal blood flow and function. We evaluated the effects of epidural anesthesia on renal function in patients undergoing total abdominal hysterectomy with general anesthesia. Methods : Thirty patients were randomized to groups I (n = 15) or II (n = 15). The epidural catheter was inserted via 17 gauge Tuohy needle through the L2-L3 intervertebral space of the patients in both groups, only in group II, the patients received 15 ml of 0.125% bupivacaine. All the patients were anesthetized with enflurane, nitrous oxide and oxygen. We measured mean arterial pressure and urine output, creatinine clearence, Na clearence, fractional excretion of Na and free water clearance during operation and compared the data between the two groups. Results : Mean arterial pressure was lower in group II than in group I (P $lt; 0.05), but other data were not different significantly between the two groups. Conclusions: Renal function was maintained even though epidural anesthesia reduced mean arterial pressure. (Korean J Anesthesiol 2000; 38: 278~282)

압전지능구조물의 최적설계를 위한 민감도 해석

김재환 한국소음진동공학회 1998 소음 진동 Vol.8 No.2

This study aims at performing sensitivity analysis of piezoelectric smart structure for minimizing radiated noise from the structure, The structure consists of a flat plate on which disk shaped piezoelectric actuator is mounted, and finite element modeling is used for the structure. The finite element modeling uses a combination of three dimensional piezoelectric, flat shell and transition elements so thus it can take into account the coupling effects of the piezoelectric device precisely and it can also reduce the degrees of freedom of the finite element model. Electric potential on the piezoelectric actuator is taken as a design variable and total radiated power of the structure is chosen as an objective function. The objective function can be represented as Rayleigh's integral equation and is a function of normal displacements of the structure. For the convenience of computation, all degrees of freedom of the finite element equation is condensed out except the normal displacements of the structure. To perform the design sensitivity analysis, the derivative of the objective function with respect to the normal displacements is found, and the derivative of the norma displacements with respect to the design variable is calculated from the finite element equation by using so called the adjoint variable method. The analysis results are compared with those of the finite difference method, and shows a good agreement. This sensitivity analysis is faster and more accurate than the finite difference method. Once the sensitivity analysis program is used for gradient-based optimizations, one could achieve a better convergence rate than non-derivative methods for optimal design of piezoelectric smart structures.

국내 인공 어초 시설의 현황

김재환,강석표,김창길,권영진,김무한 한국콘크리트학회 2002 콘크리트학회지 Vol.14 No.2

가축사육의 지역분류와 공간이동에 관한 연구

김재환,박치호,강희설,곽정훈,최동윤,최희철 한국축산환경학회 2001 축산시설환경학회지 Vol.7 No.1

The following statistics are the results of a survey that analyzed the classification of livestock area and spatial mobility based upon the number of livestock and an area of 151 towns and cities from 1975 to 1995. 1. As a results of analysis about the degree of location concentration using C.V., Korean native cattles (HanWoo) and swines are becoming more centralized while dairies and chickens are becoming decentralized. 2. 49 regions, that is 32.5%, were classified as growing regions, 30 regions (19.9%) were stagnant regions and 72 regions (47.7%) were withering regions. The classification was based upon the calculation according to the numbers of converted grown animals and growth index. Kyonggi-do and Chungchongnam-do, specifically, took up 26.6% and 24.5% of the developing regions which shows that these two regions are the dominant regions for livestock. 3. Kyongsangbuk-do and Chungchongnam-do play significant roles for overall livestock, and Chollanam-do is considering a transition from swines to Korean native cattles and Kyongsangbuk-do is shifting from Korean native cattles to swines.

지구 기후변화와 마취통증의학과 의사의 역할

김재환 대한의사협회 2021 대한의사협회지 Vol.64 No.12

Background: Environmental issues and health problems related to global climate change are becoming increasingly serious. An effective eco-friendly strategy is required to reduce medical waste and greenhouse gas emissions caused by anesthesia in hospitals. Current Concepts: Inhalation anesthetics are very strong greenhouse gases in the order of desflurane, isoflurane, nitrous oxide, and sevoflurane. Anesthetics with high global warming potential and long atmospheric lifetimes should be used with caution. Only the minimum required dose of an anesthetic drug with a low persistence bioaccumulation toxicity index is recommended for use. Disposable anesthesia products are known to have a low purchase price and low risk of cross-contamination; however, this may not be the case. By using eco-friendly anesthetic supplies, recycling and reuse, we can avoid wasting money and resources. Discussion and Conclusion: Greenhouse gas emissions from the use of anesthetics are excluded from United Nations regulations due to their necessity. However, while guaranteeing patient safety, anesthesiologists must fulfill their professional ethical obligations by striving to reduce medical waste and greenhouse gas emissions.

An orthodontic approach for Class III malocclusion in a pediatric cancer patient: A case report

김재환,지명관 조선대학교 치의학연구원 2019 Oral Biology Research (Oral Biol Res) Vol.43 No.1

Leukemia is a cancer that arises in the hematopoietic system, and the most common leukemia in children is the acute lymphoid leukemia (ALL). However, modern advances in therapeutic approaches have greatly increased the chances of survival. As the number of survivors of childhood cancer increases, more patients with cancer history seek orthodontic treatment. Certain dental conditions may require modifications to general orthodontic care in order to reduce or prevent adverse treatment outcomes in patients with histories of cancer, but orthodontic training courses do not often cover these specific aspects. The objective of this case report was to discuss the complications of chemotherapy related to dental development and document the outcomes of a first-phase orthodontic treatment of Class III malocclusion in a pediatric patient with a history of ALL.

A Study on the Establishment of a Sustainable Smart City Project Evaluation System Based on Proptech Technology Demand

김재환,심희철 한국주거환경학회 2023 주거환경(한국주거환경학회논문집) Vol.21 No.1

This study establishes a system to evaluate smart city projects based on the demand for proptech. This tailored evaluation method can be used for projects in each region in the future. The evaluation system was established by dividing the topic into three sectors: proptech, smart city living lab, and smart city project planning. This study established an evaluation system through selected evaluation items, and calculated the importance of each item through this. The importance is determined by the recognition results of experts and practitioners related to smart city projects. The analysis showed that the evaluation field was 0.609, 0.420, and 0.410 for proptech, smart city living lab and smart city project planning, respectively. Lastly, this study proposed a customized evaluation system with a focus on providing methodological applications and alternatives and verifying their utilization.