동합금에 대한 증류수내에 Water cavitation peening 특성 평가

김성종,박재철,김민성,장석기 한국표면공학회 2011 한국표면공학회 학술발표회 초록집 Vol.2011 No.11

5000계열 Al 합금의 캐비테이션 특성에 관한 워터 캐비테이션 피닝의 영향

김성종,현광용,Kim, Seong-Jong,Hyun, Koang-Yong 해양환경안전학회 2012 海洋環境安全學會誌 Vol.18 No.5

최근 FRP 선박의 폐선 처리문제, 환경 규제의 강화, 자원 재활용 등의 관점에서 소형 알루미늄 합금 선박의 건조가 증가하는 추세이다. 그러나 알루미늄은 가볍기 때문에 해양에서 고속으로 운행 가능한 알루미늄 선박은 캐비테이션이 발생되어 기포붕괴에 따른 큰 충격압력에 의해 캐비테이션 침식이 일어남으로서 재료의 수명에 있어 문제점을 드러내고 있다. 따라서 본 연구에는 캐비테이션에 의한 손상을 방지하여 내구 수명을 연장시키기 위한 방법으로 워터 캐비테이션 피닝 기술을 선박용 알루미늄 합금에 적용하였다. 이를 위하여 워터 캐비테이션 피닝을 실시하여 내캐비테이션 특성이 가장 우수한 적용 시간을 규명하였다. 선박용 알루미늄 합금 5456-H116, 5083-H321 그리고 5052-O는 워터캐비테이션 피닝을 실시함으로써 내캐비테이션 특성이 워터 캐비테이션 피닝을 하지 않은 시편보다 무게감소량이 각각 42.11 %, 50.0 % 그리고 25.7 % 개선되었다. Recently, the construction of the small Al alloy ships is an increasing trend in viewpoint such as the disposal issue of a retired ship, the enhancement of environmental regulation and resources recycling etc. for FRP ships. However, Al alloy ship which can achieve high speed by light weight in marine environment is exposed to a problem on materials damage by cavitation-erosion which is generated by large impact pressure with the collapse of air bubbles due to cavitation. Consequently, in this study, water cavitation peening technology was applied in Al alloy for ship to enhance durability life by preventing cavitation damage. So, the water cavitaton peening application time that presented the excellent cavitation characteristic investigated. The weight-loss of 5456-H116, 5083-H321 and 5052-O Al alloy at the optimum water cavitation peening time were improved to 42.11 %, 50.0 % and 25.7 %, respectively.

정전위 SSRT법에 의한 해양구조물용 Cu함유 고장력저합금강의 수소취성한계전위 규명에 관한 연구

김성종,박태원,심인옥,김종호,김영식,문경만 한국해양대학교 해양과학기술연구소 2001 硏究論文集 Vol.10 No.1

A marine structural material was well known to have high tensile strength, good weldability and proper corrosion resistance . Cu-containing high strength low alloy (HSLA) steel was recently developed for their purposes mentioned above, And the steel is free about preheating for welding, therefore it is reported that shipbuilding cost by using it can be saved more or less. However the marine structural materials like Cu-containing HSLA steel are being generally adopted with cathodic protection method in severe corrosive environment like natural sea water but the high strength steel may give rise to Hydrogen Embrittlement due to over protection at high cathodic current density for cathodic protection. In this study, Cu-containing HSLA steel using well for marine atructure was investigated about the susceptibility of Hydrogen Embrittlement as functions of tensile strength, strain ratio, fracture time, and fracture mode, etc. and an optimum cathodic protection potential by slow strain rate test(SSRT) method as well as corrosion properties in natural sea water. And its corrosion resistance was superior to SS400 steel , but Hydrogen Embrittlement susceptibility of Cu-containing HSLA steel was hider than that of SS400 steel. However Hydrogen Embrittlement of its steel by SSRT method was showed with pheonomena such as decreasing of fracture time. strain ratio and fracture mode of QC (quasi-cleavage) Eventually it is suggested that an optimum cathodic protection potential not presenting Hydrogen Embrittlement of Cu-containing of HSLA steel by SSRT method was from-770mV(SCE) to - 900mV(SCE) under natural sea water. (Received September 21, 2000)

靑少年 問題에 대한 刑事政策的인 對策

金成鐘 啓明大學校 행동과학연구소 1991 啓明行動科學 Vol.4 No.1

最近 10年間의 우리나라 靑少年의 犯罪동향을 살펴보면 첫째 低年?化 趨勢 둘째 再犯率의 增加 셋째 學生犯罪의 增加 넷째 彈力犯의 增加等이 特色으로 냐타나고 있다.

[행복일기_샘터상 생활수기 가작] 사선(死線)에서

김성종 샘터사 2014 월간 샘터 Vol.532 No.-

SCM440강 용접부의 내식성에 미치는 용접후 열처리효과에 관한 전기화학적 연구

김성종,김진경,김종호,김기준,김영식,문경만 한국해양대학교 해양과학기술연구소 2000 硏究論文集 Vol.9 No.1

The effect of poet-weld heat treatment(PWHT) of SCM440 steel was investigated with parameters such as micro-Vickers hardness, corrosion potential, polarization behaviors, galvanic current, Al anode generating current and Al anode weight loss, etc. Each hardness of three paras(HAZ, BM, WM) by PWHT is lower than each of as-welded parts. However, hardness of WM area was the highest among those three parts in case of both PWHT and as-welded. Corrosion potential of WM part was the highest among those three parts and WM area was also acted as cathode without regard to PWHT. The magnitude of corrosion potential difference among three parts by PWHT was larger than that of three parts of as-welded, and corrosion current by galvanic cell of these three pacts by PWHT was also larger compared to as-welded. Therefore, it is suggested that corrosion resistance property of SCM440 steer is decreased by PWHT than as-welded. However, both Al anode generating current and anode weight loss were also increased by PWHT compared to as-welded when SCM400 steed is cathodically protected by Al anode.

영어의 There존재문에서의 한정제한에 관한 연구

金成鍾 西原大學校 1989 西原大學 論文集 Vol.23 No.-

We have discussed Milsark's, Safir's, and Hannay's explanations about the NPs after the verv be in English there existentials. And we have made our proposal. First of all, it has been proved that Milsark's Definiteness Restriction is not appropriate. He explains that all the NPs excluded in the there sentences have the expressions of univeral guantification. But he excludes the NPs with the word most or partive expressions, which are non-universal quantifiers. However, partives actually appear in there sentences. And he says that definite NPs can appear only in there sentences with reading which is not true, because we can find definite there sentences with other readings. We have found that Safir's Definiteness Effect is also inappropriate. He tries to explain it syntactically within the framework of GB theory. He proposes an exception condition called INPP, which has proved not to be empirically supported.And he divides the verb be into two kinds, that is, PBE and IBE, but it seems to be only an artifact to justify his syntactic theory. His explanation can not solve the contradiction between the sentences (1a-1b) and (2a-2b). And Hannay's proposal based on Focality Condition seems to be persuasive. He tries to explain it from the viewpoint of functional grammar. According to him, definite terms can appear quite naturally in there sentences as long as they have salient information in the given setting. Finally, we can summarize our proposal as follows: The meaning of there construction is the assertion of the existence of an entity or a state of affairs. But the concept of existence should be understood to include not only the physical world but also the discourse world. In the former only indefinites can occur, while in the latter, both definites ane indefinites can be used. It is clear that the acceptability or unacceptability of a there sentence is ultimately a dis-course-pragmatic phenomenon determined by the discourse context in which it appears.

오류분석을 통한 효율적인 영어관사 지도자료 연구

김성종 서원대학교 교육연구소 2000 敎育發展 Vol.19 No.2

The purpose of this study is to offer the efficient teaching materials of English articles by examining the detailed usages of the English articles and analyzing the students' errors in using the English articles. The usages of the English articles can be abstracted as follows : First, the usages of the English definite article can be divided into eight kinds. Second, the usages of the English indefinite article can be divided into fifteen kinds. Third, the usages of the English zero article can be divided into twenty five kinds. Fourth, The positions of the articles can be divided into the normal position and the abnormal position Next, some important results of the error analysis can be abstracted as follows : First, the total percentage of the errors in the usages of the English articles of the total 67 students is 45%. Second, the percentage of the errors in the usages of the English zero article is 67%, the percentage of the errors in the positions of the English articles is 42%, the percentage of the errors in the usages of the English definite article is 36%, and the percentage of the errors in the usages of The English indefinite article is 28%. Third, the sophomore students and the junior students make almost the same kinds of errors in using the English articles. Fourth, the number of usages of the English definite article, indefinite article, and zero article, the error percentage of which is more than 70%, is five, one, and eleven, respectively. In conclusion, for the Korean students, whose native language does not have the same article system as English, it is natural that the percentage of errors in the usages of the English articles is high, but the error percentage could be much lowered by efficiently using the usages of the English articles examined in this study and the results of the error analysis as teaching materials of the English articles.

해수 파이프 리인 내의 전기방식에 관한 연구

김성종,김진경,이명훈,김기준,이진열,문경만 한국표면공학회 1998 한국표면공학회 학술발표회 초록집 Vol.1998 No.-

알루미늄 합금 회생양극의 성능에 미치는 오염도의 영향

김성종,김기준,이명훈,문경만 한국표면공학회 1997 한국표면공학회 학술발표회 초록집 Vol.1997 No.-