용액 침전법에 의한 SLS 3-D 프린팅용 폴리프로필렌 파우더 개발

장희수(Hee-Soo Jang),강종원(Jongwon Kang),강호종(Ho-Jong Kang) 한국고분자학회 2021 폴리머 Vol.45 No.2

폴리프로필렌/폴리에틸렌(PP/PE) 공중합체를 용액 침전법에 의하여 selective laser sintering(SLS) 3-D 프린팅이 가능한 분말로 제조 후, 이를 상업용 SLS 3-D 프린팅용 폴리프로필렌(PP) 분말에 바인더로 사용하였다. 첨가된 PP/PE 공중합체 분말이 상업용 PP 분말의 흐름특성과 SLS 3-D 프린팅 가공 윈도우에 미치는 영향을 살펴보았다. 제조된 PP/PE 공중합체 분말은 구형으로 만들어져 상업용 PP 분말의 흐름특성을 향상시켜 SLS 3-D 프린팅용 분말 recoating 특성이 개선됨을 알 수 있었다. PP/PE 공중합체의 낮은 용융온도와 냉결정화온도는 PP/PE 공중합체 분말이 바인더로 낮은 온도에서 상업용 PP 분말 융착을 가능하게 하여 융착 후 냉각 과정 중 발생하는 융착층의 치수변형을 최소화할 수 있어 recoating 공정 개선효과를 예측할 수 있다. Polypropylene/polyethylene (PP/PE) copolymer powder was successfully prepared by solution precipitation method and it was introduced as a binder for sintering commercial PP powder for selective laser sintering (SLS) 3-D printing. Effects of PP/PE copolymer powder on flowability and operation window of SLS 3-D printing were investigated. It was found that PP/PE copolymer powder showed a spherical shape and this resulted in good flowability with the mixing of commercial PP powder. Due to the low melting temperature and cold crystallization temperature of PP/PE copolymer powder, it may be used as a binder for commercial PP powder to sinter at lower temperature during SLS 3-D printing. Since commercial PP powder can be printed at relatively low processing temperature with the aid of PP/PE copolymer, the enhancement of dimensional stability in sintered layer was achieved and this could translate into a better powder recoating process in continuous sintering process.

초등학교 학모의 통합교육에 대한 객관적, 주관적 태도 비교

최성규 ( Sung Kyu Choi ),장희수 ( Hee Soo Jang ) 한국정서.행동장애아교육학회(구.한국정서학습장애아교육학회) 2005 정서ㆍ행동장애연구 Vol.21 No.1

유아의 사회도덕성에 관한 연구 : 사회인구학적 특성을 중심으로

문예은(Mun, Ye Eun),장희수(Jang, hee soo),이주연(Lee, Joo-Yeon) 한국부모놀이치료학회 2021 한국부모놀이치료학회지 Vol.- No.11

This study examined the sociomorality of young children and analyzed socio-demographic factors influence on the sociomorality. Participants of this study were the mothers who have 3-5 years children enrolled in daycare center and the daycare teachers. The mothers answered about children’s socio-demographic information and the teachers measured children’ sociomorality. The data from total 213 questionnaires were analyzed by SPSS 25.0. The results of this study were as follows. First, sociomorality of children overall was positive, and the score of violent action subfactor was the highest. Second, sociomorality had significant correlation with children’ sex, father’s age and father’s education level. Third, children’ age was a significant influential factor on life dignity, honesty, rules, etiquette subfactor, while father’s education level only statistically impacted on violent action subfactor. Father’s age influenced on orders, and children’ age and sex influenced on rules. Based on the results, the present study suggested several future directions for the advanced studies concerned with sociomorality.

부분균형모형을 이용한 전복 수급전망모형 구축에 관한 연구

한석호 ( Suk-ho Han ),장희수 ( Hee-soo Jang ),허수진 ( Su-jin Heo ),이남수 ( Nam-su Lee ) 한국수산경영학회 2020 수산경영론집 Vol.51 No.2

The purpose of this study is to construct an outlook model that is consistent with the “Fisheries Outlook” monthly published by the Fisheries Outlook Center of the Korea Maritime Institute(KMI). In particular, it was designed as a partial equilibrium model limited to abalone items, but a model was constructed with a dynamic ecological equation model(DEEM) system taking into account biological breeding and shipping time. The results of this study are significant in that they can be used as basic data for model development of various items in the future. In this study, due to the limitation of monthly data, the market equilibrium price was calculated by using the recursive model construction method to be calculated directly as an inverse demand. A model was built in the form of a structural equation model that can explain economic causality rather than a conventional time series analysis model. The research results and implications are as follows. As a result of the estimation of the amount of young seashells planting, it was estimated that the coefficient of the amount of young seashells planting from the previous year was estimated to be 0.82 so that there was no significant difference in the amount of young seashells planting this year and last year. It is also meant to be nurtured for a long time after aquaculture license and limited aquaculture area(edge style) and implantation. The economic factor, the coefficient of price from last year was estimated at 0.47. In the case of breeding quantity, it was estimated that the longer the breeding period, the larger the coefficient of breeding quantity in the previous period. It was analyzed that the impact of shipments on the breeding volume increased. In the case of shipments, the coefficient of production price was estimated unelastically. As the period of rearing increased, the estimation coefficient decreased. Such result indicates that the expected price, which is an economic factor variable and that had less influence on the intention to shipments. In addition, the elasticity of the breeding quantity was estimated more unelastically as the breeding period increased. This is also correlated with the relative coefficient size of the expected price. The abalone supply and demand forecast model developed in this study is significant in that it reduces the prediction error than the existing model using the ecological equation modeling system and the economic causal model. However, there are limitations in establishing a system of simultaneous equations that can be linked to production and consumption between industries and items. This is left as a future research project.

방류수 유량계(전자기유량계, 파샬플룸)의 특성평가 연구

안양기(Yang-ki An),김지영(Jee-young Kim),김금희(Kum-hee Kim),장희수(Hee-soo Jang),정정필(Jung-pil Jung),최종우(Jong-woo Choi) 한국유체기계학회 2015 한국유체기계학회 논문집 Vol.18 No.6

Alkyl/Vinyl-표면개질된 Nanosilicas의 LSR-나노콤포지트 HVDC 전기적 및 기계적 특성

함성호(Seong Ho Ham),송창훈(Chang Hun Song),최승민(Seung Min Choi),장희수(Hee Soo Jang),유재우(Jae Woo Yoo),윤영빈(Young Been Yoon),이병훈(Byung Hun Lee),김찬성(Chan Seong Kim),조승민(Seung Min Jo),이지희(Ji Hee Lee),박재준,김영선(Young 대한전기학회 2020 대한전기학회 학술대회 논문집 Vol.2020 No.7

나노 실리카의 친수성 표면은 다양한 비율의 알킬실란 및 비닐 실란 커플 링 제로 변형시킴으로써 소수성 특성으로 변화된다. 실리콘 고무 나노 복합체에서 고전압 직류(HVDC) 항복 전압 및 인장 특성에 대한 개질 된 나노 실리카의 효과를 중전기 장비에 적용하기 위해 연구 하였다. 표면 개질은 푸리에-변형 적외선 분광법 (FT-IR) 분석에 의해 확인되고 알킬 / 비닐 커플 링제의 중량은 열 중량 분석 (TGA)에 의해 측정된다. 실리콘 고무 나노 복합물은 액체 실리콘 고무(LSR)와 개질 된 나노 실리카를 혼합함으로써 제조된다. LSR대 나노 실리카의 혼합비는 20 중량 %로 고정된다. LSR 매트릭스에서 나노 실리카 입자의 균일 한 분산을 관찰하기 위해, 투과 전자 현미경 (TEM)이 사용되고 표면-개질 된 나노 실리카는 20 내지 100 nm 크기의 나노 클러스터 형태로 잘 분산되어있는 것으로 밝혀졌다. 알킬 실란 : 비닐 실란의 표면 개질 비가 50 일 때 전기적 특성 (± HVDC 파괴 강도 및 유전 특성)및 기계적 특성 (인장 강도 및 파단 신율)이 추정되며 ± HVDC 파괴 강도 및 인장 강도가 최대 : 50 중량 %.

부유물질 연속자동측정기 기준물질의 선정

안양기 ( Yang Ki An ),박종환 ( Jong Hwan Park ),홍경기 ( Gyeung Ki Hong ),장희수 ( Hee Soo Jang ),최성헌 ( Sung Hun Choe ),최종우 ( Jong Woo Choi ) 한국환경분석학회 2011 환경분석과 독성보건 Vol.14 No.4

Suspended solid (SS) is a particulate matter less than 2 mm in water and an important indicator of Environmental Water Quality. SS was traditionally analysed by weighing in laboratory. Recently, automatic continuous measurement of SS was included as a routine monitoring of Water Tele-Monitoring System (TMS) in Korea by "Law for Environmental Testing and Inspection" and by "Law for Water Quality and Aquatic Ecosystem Preservation." However, the standard material for this automated SS analysis is not well defined in the Korean official method. The research used microcrystalline cellulose which is the standard material of ISO 11923 as a reference material and used cellulose fiber medium and Inulin as comparative materials which have same molecular formula with microcrystalline cellulose. Recovery rates of microcrystalline cellulose, cellulose fiber medium, and Inulin were 100.1%, 100.5%, and 30.9%, respectively. Some part of Inulin was dissolved in distilled water, so it cannot be used for the standard material. The variation coefficients of microcrystalline cellulose, cellulose fiber, and inulin were 5.5%, 7.7%, and 6.0%, respectively. The correlations between laboratory SS and TMS results for all materials were very high (r > 0.99). It seems like that microcrystalline cellulose suggested by ISO can be the best standard material for TMS within the conditions tested in this research.

액션리서치를 활용한 부모협동 어린이집의 부모참여 프로그램 연구

서진영 ( Jin Young Seo ),윤정민 ( Jeong Min Yun ),장희수 ( Hee Soo Jang ),박예랑 ( Ye Rang Park ),이주연 ( Joo Yeon Lee ) 열린부모교육학회 2015 열린부모교육연구 Vol.7 No.4

본 연구는 액션리서치(action research) 방법을 통해 현장중심의 문제해결형 연구로 진행되었다. 부모협동 어린이집으로 인가받아 운영되고 있는 A어린이집을 연구대상으로 선정하였으며, 해당 어린이집의 원장 면접을 통해 효과적인 부모참여 프로그램 개발을연구의 주제로 선정하였다. 연구의 목적을 달성하기 위해 A어린이집의 원장 1명과 교사 7명 및 기관을 이용하는 학부모 44명을 대상으로 부모참여 프로그램에 대한 인식과 만족도에 대해 조사하였으며, 수집된 자료의 분석을 통해 A어린이집 부모참여 프로그램을 위한 맞춤형 제안을 제공하였다. 다음은 A어린이집 원장 및 교사, 부모들을 대상으로 부모참여 프로그램에 대한 인식과 만족도를 조사한 결과이다. 첫째, 기존 부모참여 프로그램 중 만족도가 높은 항목은 발표회, 부모교육, 전화상담 순으로 나타났다. 또한 기존프로그램 중 좀 더 강화하기를 원하는 부모참여 프로그램 조사 결과 학부모들은 키즈노트/원아수첩, CCTV공개, 전화상담 순으로 나타났다. 둘째, 기존 프로그램에 대한 교사의 만족도와 강화의견 및 신규 부모참여 프로그램에 대한 필요도 조사 결과 ‘발표회’,‘엄마참여수업’, ‘아빠참여수업’에 대한 만족도가 가장 높게 나타났다. 또한 기존의 부모참여 프로그램 중 강화하길 원하는 프로그램으로는 아빠참여수업을 선택하는 교사가 가장 많았다. 신규 부모참여 프로그램에 대한 교사의 필요도를 조사한 결과 교사는 부모 일일교사가 가장 필요하다고 응답하였다. 셋째, 부모참여 프로그램에 대한 원장 인터뷰 결과 아빠참여수업과 부모참여수업에 대한 학부모와 교사의 참여의 활성화 등에 관심을 가지고 있는 것으로 나타났다. A어린이집 모든 구성원의 부모참여 프로그램에 대한 인식조사결과를 바탕으로 본 연구는 A어린이집의 부모참여 활성화를 위한 프로그램의 실제적인 개발방향을 제안하였다는 점에서 연구의 의의가 있다. The purpose of this study was to exmaine an efficient field-specific parent participation program for the ``A`` parent cooperative daycare center. Using an action research design, one head director of the ``A`` childcare center was interviewed and 7 teachers from the ``A`` childcare center and 44 parents whose child are enrolled in the ``A`` childcare center were surveyed about their perception and satisfaction on the specific parent participation programs. The results of the research were as follows. First, parents satisfied with chlid’s work presentation, parent education, telephone counseling, and Kid``s notes/Kindergarten Handbook in its order. Also, they wanted to strengthen Kid``s notes/Kindergarten Handbook, CCTV public, and telephone counseling. Second, the teachers recognized several new programs such as Parent teacher for one day, Parent’s talent donation, Camping with dad are needed. Third, the head director was interested in the activation of Parent teacher for one day and Dad participating class. Based on these results, the present study suggested several field-specific parent participation programs for the ``A`` childcare center.

줄넘기 운동이 고등학교 비만 남학생의 건강체력 및 비만 스트레스 해소에 미치는 영향

권봉안,장희수,정순광 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.6

This study is to understand the effect of rope jumping on health related physical strength and obesity stress of high school obese students. The subject of this study was 40 1st and 2nd grade obese male students attending at P high school located in Goyang-City, Kyunggi-province as of the 1st semester, 2003 school year. As the study instrument, a questionnaire of physical strength items and obesity stress was used. To analyze the effect of rope jumping on health related physical strength, physical strength items were adopted, and to analyze the effect of rope jumping on the relief of obesity stress, the questionnaire was used. The questionnaire was asked to answer questions by Self-administration method to 20 subjects of the experiment group participating at rope jumping. As the questionnaire, health related pre-physical strength test was performed along with the 1st survey and the 2nd survey was carried after exercise, then health related physical strength test was carried out. The collected data were analyzed using SPSS/Windows 10.0 statistical program, and average and standard deviation by the sub-factor of each factor was calculated and to understand differences using groups and periods, 2x3 2-way variance analysis(ANOVA) by repeated measurement was carried out. In case interaction of two factors, that is, character and school year, post-verification using Duncan's multiple range test was made, when significance level will be set at α=.05. Based on the above research procedure and data analysis, following conclusion is as follow. 1) In the change of health physical strength by exercise participation of high school obese male students, there was no significant difference, but muscular endurance and body fat were different. 2) In the change of health physical strength by exercise participation of high school obese male students, there was no significant difference before and after exercise, but difference after exercise. 3) In the individual difference by rope jumping participation of high school obese male students, there was no significant difference in school year and character, but difference in obesity. 4) In the exercise programs by rope jumping participation of high school obese male students, there was no significant difference in school year and character, but difference in obesity.