탄산가스 아크용접에서 보호가스량에 따른 용접부의 기계적 성질

정회범,김봉태 順天大學校 1998 論文集 Vol.17 No.1

The mechanical properties of a welding part have been examined by varying the shield gas flow rate from 0ℓ/min to 24ℓ/min when the CO₂ gas arc welding with solid wire is used for welding the SS41 steel. The welding parts have been investigated through X-ray film test, bending test and tensile test, which have shown following results ; 1) X-ray film tests show no pores for the shield gas flow rate from 6ℓ/min to 24ℓ/min. But some pores are existed at inner welding part for the flow rate 2ℓ/min and 4ℓ/min. When no gas is supplied, many pores are observed at the inner and the outer welding parts. 2) A bead configuration including a fusion depth and a bead's width and height is good for the shield gas flow rate more than 8ℓ/min. 3) Bending tests show that no cracks were developed for the shield gas flow rate 16ℓ/min to 24ℓ/min. But cracks are developed at the surface of a face side for the flow rate 4ℓ/min to 12ℓ/min. For the flow rate 0ℓ/min and 2ℓ/min, specimens break into pieces. 4) Tensile strength of the welding part increases as the shield gas flow rate increases. The tensile strength of the welding part is much higher than that of the base metal for the flow rate 4ℓ/min to 24ℓ/min. Considering the above results, the effective shield gas flow rate in the CO₂ gas arc welding is 16ℓ/min to 24ℓ/min.

유한요소법에 의한 도파관 급전 캐비티의 전자계해석

정봉식,안창회 嶺南大學校 工業技術硏究所 1994 工業技術硏究所論文集 Vol.22 No.2

Electromagnetic fields of the rectangular waveguide-loaded cavity are calculated using finite element method. Magnetic field vectors are used as vector variables with edge basis functions. The cavity analyzed in this paper is loaded by the rectangular waveguide only ?? mode excited. Also complex reflection coefficients are obtained.

고등학생의 환경에 대한 인지도에 따른 환경오염 방지를 위한 실천도

장봉기;최재호;박상일 순천향대학교 기초과학연구소 2010 순천향자연과학연구 논문집 Vol.16 No.1

In this study, high school students' recognition of the environment by looking out, practical help for evaluation the relationship between environmental education and the issue is to establish policy. Regarding the results that high school students recognition of the environmental terms, the pollution degree of recognition about the cause of the higher interest, higher environmental practice was also affecting.

메타인지적 지식과 작동기억이 메타인지적 규제 요구 과제의 성취에 미치는 영향

진화봉,이순아,김회수 한국교육정보미디어학회 2003 교육정보미디어연구 Vol.9 No.3

본 연구는 자기주도적 학습 능력의 핵심요소로 강조되는 메타인지가 작동기억의 중앙집행장치와 어떤 관계에 있는지 경험적 연구를 통해 밝히고자 하였다. 이를 위해 초등학생을 대상으로 세 개의 실험집단과 한 개의 비교집단을 구성하여, 메타인지적 지식과 작동기억이 메타인지적 규제 요구 과제의 성취도에 어떤 영향을 주는지 검토하였다. 실험 결과, 메타인지적 지식 수준이 높은 피험자는 낮은 피험자보다 메타인지적 규제를 요구하는 과제에서 더 높은 성취도를 나타냈다. 작동기억 용량에 따른 메타인지적 규제 요구 과제 성취도에 미치는 효과분석에서는 중앙집행장치와 언어적 작동기억을 제외한 시· 공간적 작동기억이 성취도에 영향을 미치는 것으로 나타났다. 그러나 시 · 공간적 작동기억 검사도구의 신뢰도가 높지 않았기 때문에 이 문제에 대한 결론을 확정하기 위해서는 추가적인 반복실험이 필요하다. 작동기억을 억제했을 때의 메타인지적 규제 요구 과제 성취도는 예측했던 대로 중앙집행장치 억제집단이 비교집단에 비해 유의미하게 낮고, 네 집단 중에서도 가장 낮은 것으로 나타났다. 이 결과는 메타인지적 규제 요구 과제가 중앙집행장치의 많은 인지적 자원을 필요로 하기 때문에 중앙집행장치 용량의 상하에 따른 성취도는 차이가 나타나지 않지만, 중앙집행장치를 억제하면 성취도는 크게 떨어지는 것으로 해석된다. 본 연구결과는 메타인지적 규제의 기능을 작동기억의 중앙집행장치가 담당하며, 메타인지적 규제능력이 높은 학습자는 자기주도적 학습에서 성공할 가능성이 높다는 것을 시사한다. 따라서 자기주도적 학습을 메타인지적 규제의 관점에서 접근하는 연구는 작동기억의 중앙집행장치를 고려해야 보다 설명력 있는 결과를 얻을 수 있을 것이다. This study was to examine the relationship between two components of metacognition and working memory that were considered as critical constructs to have influence on self-directed learning. The subjects were 140 sixth graders. They were randomly assigned to the three experimental groups and the control. Three experimental groups were given tasks requiring metacognitive regulation and concurrent working memory suppression tasks. The control group performed only the task requiring metacognitive regulation. The results of this study were as follows: The subjects with high metacognitive knowledge got higher achievement in the task requiring metacognitive regulation than the low metacognitive knowledge group. Visuo-spatial working memory span affected task performance requiring metacognitive regulation. However, because of low reliability of visuo-spatial span test additional experiments are necessary to confirm the results. As expected, the central executive suppression group showed significantly lower performance of metacognitive regulation tasks than the control group. Also the other groups got the lowest achievement. The findings suggested that the central executive would play the role of metacognitive regulation and the students with high metacognitive regulation skills would be successful in self-directed learning. It is desired that the study regarding the relationship between self-directed learning and metacognitive regulation skills consider the students' central executive capacity.

클라이언트/서버 환경에서 트랜잭션 흐름 제어를 고려한 최적 서버 할당 알고리즘

박진섭,김봉회 大田大學校 産業技術硏究所 1996 산업기술연구소 論文集 Vol.7 No.2

This paper describes an optimal static server allocation algorithm with transaction flow control using mean value analysis in multiprocessing based client/server environment. We present an analytical methodology for the analysis and performance evolution of server allocation algorithm. Using mean value analysis, performance are obtained. It is the throughput, end-to-end delay time, a multiprocessor utilization and system power. The goal in this paper is to determine the optimal parameter value such as the number of transaction and server instantiation in the system, which affect the configuration of the critical hardware resource.

CHILL 프로그램 검증을 위한 테스팅 도구 설계 및 구현

황선명,김봉희 大田大學校 産業技術硏究所 1997 산업기술연구소 論文集 Vol.8 No.1

ATM switching software should be required high reliability, functionality, extendability and maintainability. After development of the software, it is verified and tested by analyzer whether the software is accomplished the characteristics of it or not. There are so many CASE tools in other area, but the CHILL testing tools that can verify ATM software have not various functions are not many. In this paper we develop the testing tool which can evaluate and test CHILL programmed ATM software. This Tool supports testing reports, debugging informations and maintenance informations including parallel process about CHILL original programs.

Ginkgolide B 와 SKI 5051 이 흰쥐의 간에서 PAF로 유도된 glucose 방출에 미치는 효과

조재형,강봉수,허인회 중앙대학교 약학연구소 1996 약학 논총 Vol.10 No.-

Platelet-activating factor(PAF), 1-O-alky1-2-acetyl-sn-glycero-phosphocholine (AGEPC) is shown to increase glycogenolysis in the perfused rat liver about 2-fold. In the perfused rat liver, pre-infusion of PAF receptor antagonists, ginkgolide B and its derivative, SKI 5051 decreased dose-dependently PAF-induced glucose output. Indomethacin and dexamethasone, which inhibit production of eicosanoids and Ca^2+ channel blocker, nicardipine decreased PAF-induced glucose output. too. These results suggested that PAF receptors, the biologically active eicosanoids and Ca^2+ mediate PAF-stimulated glycogenolysis in the perfused rat liver

Streptozotocin으로 유발된 당뇨병쥐의 신경전도속도에 대한 Evening primrose oil (EPO), Vit.C, Vit.E의 약물효과

신창열,류정수,김학림,강봉수,손의동,허인회 중앙대학교 약학연구소 1997 약학 논총 Vol.11 No.-

The effects of evening primrose oil (EPO). Vit.C and Vit.E on nerve conduction velocity (NCV) in streptozotocin -induced diabetic rats were investigated. 5 weeks- diabetes caused 27±0.5 % reduction in sciatic motor conduction velocity as compared with normal control. Dietary supplement of 5% EPO. 125mg/kg Vit.C. and lg/kg Vit.E prevented significantly the development of the motor nerve conduction velocity deficit about 21±0.5, 21±0.5, 26±0.5% respectively. The total serum cholesterol and triglyceride were decreased by administration 5% EPO. Vit.C, and Vit.E as compared with diabetic control. However, the serum glucose was not decreased by administration 5% EPO. 125mg/kg Vit.C but the serum glucose was decreased by administration lg/kg Vit.E as compared with diabetic control.

의료 정보 시스템 위협 요소

김봉회(Bong-hoi Kim),박진섭(Jin-sub Park) 한국멀티미디어학회 1998 한국멀티미디어학회 학술발표논문집 Vol.1998 No.2

극저온 열처리가 7075 알루미늄 합금의 잔류응력과 석출에 미치는 영향

김회봉 ( Hoi Bong Kim ),김동용 ( Dong Yong Kim ),고대훈 ( Dae Hoon Ko ),김병민 ( Byung Min Kim ),조영래 ( Young Rae Cho ) 대한금속재료학회(구 대한금속학회) 2013 대한금속·재료학회지 Vol.51 No.5

To develop 7075 aluminum (Al7075) alloy with low residual stress and high strength, a modified cryogenic treatment was proposed. In this study, the effects of two additional steps on residual stress in Al7075 were investigated. Unlike the conventional age-hardening process, the first step of the modified treatment is cryogenic quenching, followed by the second step of uphill quenching of the samples. The mechanical properties and residual stress of samples were characterized by Vickers hardness and X-ray diffraction with sin2 method, respectively. Structural properties such as size and formation of the precipitates of the samples were characterized by transmission electron microscopy and electron energy loss spectroscopy. Three different uphill quenching methods, boiling water, room temperature water, and air, were applied to the samples. Samples treated by the boiling water uphill quenching method showed the lowest residual stress and highest hardness. Results clearly demonstrated that the modified cryogenic treatment with boiling water uphill quenching method was a very useful heat treatment to achieve an age-hardened Al7075 alloy with low distortion shape, low residual stress and high hardness.