Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processedby the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ballmilling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states suchas a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine thestructural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated withthe Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures;the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coatingprocess is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). TheTiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understandingthe evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hardcoating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that correspondsto an increase in the silicon nitride contents.

A study on Choquet integrals and their applications in vague soft sets

Hyun-Mee Kim(김현미),Jeong Gon Lee(이정곤),Lee-Chae Jang(장이채) 한국지능시스템학회 2020 한국지능시스템학회논문지 Vol.30 No.5

Wang-Qu [9]는 패턴 인식, 이미지 처리, 근사 추론, 퍼지 제어 등 다양한 분야에서 광범위하게 적용할 수 있는 애매한 소프트 집합의 엔트로피, 유사성 측도 및 거리 측도를 도입했다. 또한, Jang-Kwon [3]에서 처음으로 구간값 함수의 쇼케이 적분을 정의하고 이와 관련된 성질을 조사하였다. 그이후 많은 논문에서 구간값 쇼케이적분의 응용을 연구해 왔다. 애매한 집합의 속성이 구간값 소속함수의 성질을 가지고 있음을 이용하고자 한다. 본 논문에서는 애매한 소프트 집합상에서 쇼케이 적분을 정의하고, 이들 적분에 의해 정의된 구간값 거리 측도를 조사한다. Wang-Qu [9] introduced entropy, similarity measure and distance measure of vague soft sets which can be extensively applied in many fields such as pattern recognition, image processing, approximation inference, and fuzzy control. In addition, for the first time in Jang-Kwon [3], the Choquet integral of the interval-valued function was defined and the related properties of them were investigated. Since then, many papers have studied the application of interval-valued Choquet integrals. We note that vague soft sets have the interval-valued membership functions. In this paper, by using interval-valued Choquet integrals and vague soft sets, we define the Choquet integral on vague soft sets and investigate an interval-valued distance measure defined by them.

Effect of Mechanical Alloying on the Microstructural Evolution of Al60Cr30Si10 Alloys Processed by Spark Plasma Sintering

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

In this study, Al, Cr and Si fine powders were alloyed by planetary ball milling to investigate their microstructural evolution,following their mechanical alloying behavior. The formation of Al(Cr) supersaturated solid solution by the Cr grainsembedded in Al-matrix, which contributed substitutional structure is discussed in relation to their structural evolution inaccordance with the distortion of a crystal lattice. The compacts of Al–Cr–Si alloys were prepared by rapid sintering withina short time by dense consolidation above the density of 99.9% as the formation of intermetallics, except in the case of thedistribution of single-phases induced by the Al-melting. The formation behavior of intermetallics was dominated by dependenceon the structures of the milled-powder and subsequent sintering temperature. To estimate the consolidated behaviorsof compacts, various approaches derived from TEM and XRD analysis were taken to obtain microstructural evidences ofthe inter-diffusion, following the presence of thermally stable intermetallics.

Floristic study of Jang-do (Isl.) in Korea

Son, Hyun-Deok,Gwon, Soon-Gyo,Jang, Jeong-Won,Sun, Eun-Mi,Kim, Byeol-Ah,Im, Hyoung-Tak The National Institute of Biological Resources 2013 Journal of species research Vol.2 No.2

We investigated the flora of Jang-do (Isl.), an island of the Heuksan archipelago, located in Heuksan-myeon, Shinan-gun, Jeollanam-do and discussed the remarkable plants found there. Thirteen-field trips (total 27 days) were completed from May of 2004 to May of 2013. As a result, we identified the distribution of 423 taxa in Jang-do (Isl.), comprising 104 families, 285 genera, 335 species, 78 varieties and 10 forms. There are a total of 95 taxa of floristic regional indicator plants. The floristic regional indicators are as follows; four taxa of level V such as Impatiens furcillata, four taxa of level IV such as Hosta yingeri, 14 taxa of level III such as Ophioglossum vulgatum, 5 taxa of level II, and 58 taxa of level I. In addition 10 red data plants, 2 vulnerable species (VU) including Calanthe striata for. sieboldii, and 4 least concern species (LC) like Ardisia crenata, 2 not evaluated species (NE) such as Hosta yingeri, were found in the investigated area. An unrecorded species, Fragaria (Rosaceae), was found in a forest of Jang-do (Isl.) for the first time in Korea.

바둑의 이해와 대학 바둑판과 학생들의 의식 실태에 관한 연구

정수현,박장근 명지대학교 예체능연구소 1998 藝體能論集 Vol.9 No.-

The purpose of this study is to make a general survey of Baduk, which is believed to have been invented in ancient China about 2,000 B.C. and has long been one of the main hobbies for Koreans, arid to examine what the students of the Dep. of Baduk think about various problems related to their major. Since Baduk has been regarded as an amusement and studied mainly from the technical point of view, the Department, established for the first time in history at the end of 1996, has very little material for schooling. The result from the study is, accordingly, considered helpful to making people understand the wider aspects of Baduk and to deciding on a direction of the Department. A questionnaire is given to each of 33 students(freshmen and sophomores), which contains 29 questions about one's viewpoint of his major, the reason for choosing the Baduk Department, the degree of understanding Baduk, etc. The summary of the examination is as follows: 1. In spite of uncertainty to their future, almost all students take pride in majoring; in Baduk for they study a very specific and unique subject. 2. There is outstanding distinction between freshmen and sophomores in the respect of satisfaction for their major; freshmen have a consierably clear object in their major, while sophomores tend to have a vague idea what to do after finishing the whole course. This reveals that freshmen had more opportunities to contact information about the Dep. of Baduk than sophomeres. 3. Most students take interest in learning Baduk except some sophomores who are in the lower level in the skill of Baduk. It suggests that a new student should have a high-level strength in the art of Baduk for interesting and earnest learning, and that the school authorities should make an effort to inform the existence of the Department for the purpose of inducing excellent students to enter it.

염증이 있는 충수돌기의 초음파 진단 : 자가 위치선정법의 정확도 Accuracy of Self-localization Technique

장현정,임효근,김승훈,이민희,윤지영,김경아,임재훈,정연권 대한초음파의학회 1998 ULTRASONOGRAPHY Vol.17 No.4

치료용 방사선의 입사각에 따른 광섬유 방사선량계의 체렌코프 빛 측정 및 분석

장경원,조동현,유욱재,신상훈,서정기,이봉수,박병기,문주현 제주대학교 방사선응용과학연구소 2008 방사선응용과학연구소논문집 Vol.22 No.-

In this study, we have measured scintillating light generated in a fiber-optic dosimeter by high energy photon and electron beams using a charge-coupled device. The intensity of Cerenkov lights are also measured and characterized as functions of incident angles and energies of the high energy beams from a clinical linear accelerator. To minimize or remove Cerenkov light, a simple subtraction method using a background optical fiber and wavelength discrimination method using optical filters are investigated. Also, the intensities of Cerenkov light induced by high energy photon and electron beams are compared.

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

Plyometric Training과 비타민 C 투여가 남고생의 체력, 혈중 젖산, 암모니아 및 젖산탈수소효소에 미치는 영향

장준원,김세종,이현미,서혜림,조현숙,고정림,염종우,예정복,백영호 釜山大學校 附設 體育科學硏究所 2003 體育科學硏究所 論文集 Vol.19 No.-

The purpose of this was to examine the effect of plyometric training and vitamin C ingestion on physical fitness and fatigue substance....

반도체 산업에서의 Enterprise Document Management Architecture 구현에 관한 연구

장현성,이영중,송하석,한영준,안정삼 한국경영과학회 2001 한국경영과학회 학술대회논문집 Vol.- No.2

A systematic construction and re-use of technology related to the product development and production has been the most important for the semiconductor industry dependent on process and equipment Therefore, numerous outputs in the form of paper has been produced in the process of information management ranging from the creation to recycling and disposal of technologies. In this research, the technology and documents necessary for the business management in the field of semiconductor manufacturing were classified in an effort to solve problems while the modeling of document management architecture at the enterprise level was performed by properly setting up the security system to prevent the unauthorized disclosure of the product development technology to the third parties. Especially, the product and process specification are designed in such a way as to ensure a real-time response in interface with the production system in order to shorten the development lead-time and improve the productivity. This paper is to discuss the modeling approach, the strategy to construct the system and its results.