Friction and Wear Characteristics of ABS-like Resin for 3D Printing Under Non-Lubricated Condition

조영상(Young Sang Jo),이현섭(Hyun Seop Lee) Korean Society for Precision Engineering 2019 한국정밀공학회지 Vol.36 No.12

서리피해 방지제 처리가 봄철 개화기 배과원 서리피해 방지에 미치는 영향

조영상(Young-Sang Jo),안유정(You-Jeong Ahn),조정안(Jeng-An Jo),이상현(Sang-Hyun Lee),이웅(Xiong Li),김월수(Wol-Soo Kim) 한국원예학회 2009 한국원예학회 학술발표요지 Vol.2009 No.10

Percutaneous Bone-Anchored Hearing Implant: Is It Clinically Useful in Korean?

Sung Min Koh,조영상,Ga-Young Kim,Mini Jo,Hye Yoon Seol,Il Joon Moon 대한의학회 2022 Journal of Korean medical science Vol.37 No.23

Background: The aim of this study is to investigate the clinical effectiveness of Ponto in Korea, a recently released percutaneous bone-anchored hearing implant. Methods: 16 patients with single-sided deafness (SSD) and mixed or conductive hearing loss who underwent Ponto implantation from December 2018 to September 2020 were enrolled in the study. Puretone audiometry, the Korean version of the Hearing in Noise Test (K-HINT), sound localization test (SLT), and Pupillometry were performed pre- and three months post-operation. Standardized questionnaires, the Hearing Handicap Inventory for the Elderly (HHIE) and Speech, Spatial and Qualities of Hearing Scale (SSQ), were administered. Results: The mean age of subjects was 55.5 (range, 48–67) years. Four males and 12 females participated in the study. The mean puretone average was 73.17 dB hearing level (HL) before surgery and significantly improved to 36.72 dB HL three months after surgery. The mean word recognition score improved from 26.0% to 90.75% after implantation. In the case of K-HINT, there was a significant difference in summation (Z = −2.250, P = 0.024) and head shadow effects (Z = −3.103, P = 0.002). There was no significant difference in root mean square error degree (RMSE) and hemifield identification scores for SLT testing. Pupillometry was performed to measure listening effort and the results revealed that the degree of pupillary dilatation decreased under the condition of quiet, 0 dB signal to noise ratio (SNR) and 3 dB SNR. The total score for HHIE decreased significantly (Z = −3.130, P = 0.002) while the SSQ score increased significantly (Z = −2.216, P = 0.027). Conclusions: The Ponto bone-anchored hearing system showed significant clinical benefit in Korean patients with conductive and mixed hearing loss and SSD.

방상팬과 미세살수가 개화기 배 과원의 온도와 과실생산성에 미치는 영향

조영상(Young-Sang Jo),조정안(Jung-An Jo),김월수(Wol-Soo Kim),최현석(Hyun-Sug Choi),안유정(Yoo-Jung An) 한국원예학회 2010 한국원예학회 학술발표요지 Vol.2010 No.10

비접촉 접지구조에 의한 휴대폰 MIMO 안테나 격리도 향상

조영상(Young-Sang Jo),손태호(Tae-Ho Son) 대한전기학회 2016 전기학회논문지 Vol.65 No.6

In this paper, the method of isolation enhancement for the mobile phone MIMO antenna of LTE class 40(2300〜2400㎒) was studied. Design of MIMO antenna was based on the hybrid antenna that operates both a monopole and an IFA(Inverted F Antenna). A structure for the isolation enhancement which controls induced electric field on the ground plane is located between MIMO antenna, and was not connected with the ground but apart 0.3㎜. A MIMO antenna that operates on class 3〜40(1710〜2400㎒) of LTE service bands and a structure for the isolation enhancement at the class 10 band were designed. VSWR measurement of implemented antenna on the FR4 board showed within 3:1 at entire design bands, and isolation between antennas at the class 40 band was less than –30㏈. Isolation was enhanced more than 20㏈ by the studied structure. ECC(Envelope Correlation Coefficient) for MIMO performance was under 0.1, and antenna average gain and efficiency measured in the anechoic chamber were –4.28〜-1.40㏈i and 37.32〜72.36% respectively.

친환경 농산물 재배를 위한 농가 자가제조 액비 사용실태

안난희,조영상,조정래,김용기,이연,지형진,이상민,박광래,이병모,An, Nan-Hee,Jo, Young-Sang,Jo, Jeong-Rae,Kim, Yong-Ki,Lee, Yeon,Jee, Hyeong-Jin,Lee, Sang-Min,Park, Kwang-Lai,Lee, Byung-Mo 한국유기농업학회 2012 韓國有機農業學會誌 Vol.20 No.3

We conducted a survey of actual using conditions of farm-made liquid fertilizers by investigating their formulation types, materials, making processes, using methods and various beneficial effects on 29 farms certified by National Agricultural Products Quality Management Service to produce environment-friendly agricultural products in 2009. Most of the materials used to make liquid fertilizers are those that can be easily obtained around the farms. Molasses or black sugar are added as an energy source of microorganism. And leaf mold, bacterial cultures supplied by agricultural extension centers of local governments, and cultures of native microorganisms were used as microbial sources for fermenting effective microorganisms. Types of the farm-made liquid fertilizers were fermented liquid fertilizers, fermented plant juices, amino acid liquid fertilizers, calcium-liquid fertilizers, and phosphoric acid liquid fertilizers. Effects of liquid fertilizers used by the farms were found to promote plant growth by supplying nutrition, to accelerate blooming and flower bud formation, to enhance the quality of agricultural products such as increase of sugar contents and improvement of storing conditions, to induce resistance against diseases and insect pests, and to cause endurance to high temperature stress. Chemical properties of the liquid fertilizers collected were analyzed. As a result, pH and EC range showed differences according to kinds of the liquid fertilizers. Amount of macro-nutrients, such as nitrogen and phosphoric acid, in most of the collected liquid fertilizers, was found to be low. Even though the liquid fertilizers were made from same materials, their contents was found to be different depending on the making process. 본 연구는 2009년에 친환경 농산물 재배 농가들이 사용하는 자가 제조 액비 실태를 파악하고자 친환경 농산물 인증을 받은 29농가를 대상으로 액비의 종류, 재료, 제조과정, 활용방법 및 효과 등에 대해서 조사를 실시하였다. 농가에서 사용하는 액비의 재료는 대부분 주변에서 쉽게 구할 수 있는 것들이었고 제조방법은 주재료에 미생물의 에너지원으로 사용할 수 있는 당밀이나 흑설탕을 첨가하고 그리고 발효 미생물원으로 부엽토, 시판미생물, 시군센터에서 보급하는 미생물 또는 토착미생물 배양체를 사용하고 있었다. 농가에서 제조하여 활용하고 있는 액비 종류는 발효액비, 천혜녹즙, 아미노산액비, 칼슘액비, 인산액비 등 이었고 이들 액비는 생육촉진, 개화촉진, 꽃눈형성, 당도증가, 저장성 증대, 병해충 저항성 증가, 그리고 고온장해 억제 등의 효과가 있는 것으로 조사되었다. 수집된 액비의 성분분석 결과, pH와 EC의 범위는 시료간의 차이가 크며 질소, 인산 등 다량원소 함량은 대부분 적었으며 같은 재료를 이용하여 제조된 액비라도 제조방법에 따라 양분함량이 각각 다른 것으로 조사되었다.

한국 조선해양산업의 경쟁력에 관한 실증연구 : 다이아몬드 모델과 9-팩터 모델을 중심으로

최수형(Su-Heyong Choi),조영상(Young-Sang Jo) 한국산업경제학회 2014 산업경제연구 Vol.27 No.1

본 연구에서는 한국 조선해양산업 경쟁력에 관한 실증분석을 통하여 한국 조선해양산업의 경쟁우위 전략을 모색하고자 하였다. 본 연구의 목적을 달성하기 위해 선행연구 검토 및 전문가와의 면담을 실시한 후 포터의 다이아몬드 모델 및 조동성의 9-팩터 모델을 기초로 연구모형을 설정하였다. 연구모형에 근거한 연구가설을 검증하기 위하여 한국 조선해양산업 종사자를 대상으로 실증분석을 실시하였다. 가격, 기술, 비가격, 인적자원, 정부정책 등의 독립변수가 한국 조선해양산업 경쟁력의 종속변수에 어느 정도 영향을 미치는지 가설을 설정하여 검증하였다. 실증분석 결과, 가격경쟁력, 기술경쟁력, 비가격경쟁력, 인적자원경쟁력, 정부정책이 한국 조선해양산업 경쟁력에 통계적으로 유의한 수준의 영향을 미치는 것으로 나타났다. 또한 한국 조선해양산업 경쟁력에 지역클러스터 정책 및 산학연정책이 낮은 영향을 미치는 것으로 평가되었다. 이상의 연구결과를 바탕으로 시사점 및 연구의 한계점, 향후 연구방향을 제시하였다. The purpose of this study was to empirically analyze the competitive edges of the ship-building and marine industries of Korea. Based on Porter"s Diamond Model and 9-factors model, the factors of competitive edges of the ship-building and marine industries were comparatively analyzed. Then, an empirical analysis was conducted for the Korean ship-building and marine industry workers for the first time in order to analyze the effects of such independent variables as price, technology, non-price factors, human resources and government policy on the dependent variable or the competitive edge of the Korean ship-building and marine industry. The results are that the Korean ship-building and marine industry had comparative edge in terms of price, technology, non-price factors, human resources and government policy. Also, it was founded that the Korean ship-building and marine industry was not properly supported by regional cluster policies and industry-academy-research cooperation. Lastly limitations and implications were suggested.

해외진출기업의 글로벌 가치사슬 참여형태에 따른 성과 분석

조계권(Kye-kwon Jo),조영상(Young-sang Cho) 한국기술혁신학회 2021 기술혁신학회지 Vol.24 No.2

한국은 높은 글로벌 가치사슬(Global Value Chain, GVC) 참여율을 보이고 있으며, 금융위기 이후 진행되고 있는 GVC의 구조 변화는 한국 경제에 매우 중요한 이슈이다. GVC 재편에 적절한 대응이 요구되며 이를 위해서는 GVC에 참여한 기업의 현황 및 성과 파악이 선행되어야 한다. 본 연구에서는 한국 기업의 글로벌 생산 네트워크 현황, 현지 진출기업들의 가치사슬 참여 형태, 현지 기업과 모기업의 조달 및 수출 방식 등이 해외진출기업의 성과에 어떠한 영향을 미치는지를 살펴보고 이에 기반한 정책적 시사점 도출을 목적으로 한다. 본 연구에서는 대한무역투자진흥공사(KOTRA)가 2016년과 2020년 현지 진출기업 대상 조사자료를 사용하였다. 분석 결과 다국적 기업에의 납품, 부품 및 원재료 등 가치사슬 전방 참여가 현지 진출기업의 성과에 정(+)의 영향을 미치는 것으로 나타났다. 본 연구는 기업 레벨의 미시적 자료로 해외 진출기업의 다양한 GVC 참여 형태를 고려하였으며, 도출된 시사점은 향후 GVC 재편에 대응하기 위한 관련 산업정책 수립에 활용될 수 있다. Korea has a higher participation rate of global value chain (GVC) than other countries, and the recent change in GVC since the financial crisis is a significant issue for the Korean economy. An appropriate response to the GVC reorganization is required, and it is necessary to first understand the current state and performance of GVC participating companies. Therefore, this study analyzes types of GVC participation of Korean overseas companies and the performance, and then it aims to propose policy implications for GVC participation strategies. For this, we used a survey of local companies in the year of 2016 and 2020 conducted by Korea Trade-Investment Promotion Agency (KOTRA). As a result of the analysis, we found that the thrid-country procurement and export of overseas Korean companies, multinational enterprises delivery, and the forward participation in the value chain such as parts and raw materials have positive effects on the performance of the Korean overseas companies. The results of this study and derived implications can be referred to when developing industrial policies to support GVC entry of small and medium-sized companies.

미세살수처리가 봄철 개화기 배과원 서리피해 방지에 미치는 영향

조정안(Jeong An Jo),Wu Xiu Yu,이상현(Sang Hyun Lee),조영상(Young Sang Jo),Li Xiong,안유정(You Jeong Ahn),김월수(Wol Soo Kim) 한국원예학회 2009 한국원예학회 학술발표요지 Vol.2009 No.5

연구보문 : 미세살수와 방상팬 처리가 개화기 배 과원의 서리피해 방지에 미치는 영향

최현석 ( Hyun Sug Choi ),조영상 ( Young Sang Jo ),김월수 ( Wol Soo Kim ),조정안 ( Jung An Jo ),안유정 ( Yoo Jung An ),이연 ( Youn Lee ) 한국국제농업개발학회 2011 韓國國際農業開發學會誌 Vol.23 No.3

전남 나주지역에서 ``원황`` 배 개화기간 동안 서리 피해를 막기 위한 미세살수와 방상팬의 서리피해 경감효과를 알아보기 위해서 본 시험을 수행하였다. 미세살수와 방상팬은 4월의 개화기간 중 2℃ 미만으로 떨어졌을 때만 작동되었다. 과원의 최저 온도가 0C 미만이었을 때 미세살수와 방상팬은 대조구에 비해서 온도를 상승시켰고, 이는 화서별 서리피해율을 약 50% 감소시켰고, 평균 착과수를 2배 이상 증가시켰다. 미세살수와 방상팬은 정형과 비율이 약 50%로 대조구의 38%보다 높 은 것으로 관찰되었다. 방상팬의 경우 우리나라 지형을 고려해서 여러 대의 방상팬을 서리피해 상습지대에 배치한다면 보다 효율적으로 서리피해를 방지 할 수 있을 것으로 사료되었다. This study was performed to decrease frost damage of ``Wonhwang`` pear (Pyrus pyriforia) trees by operation of sprinkler and wind machine during a flowering in Naju, Chonnam. Sprinkler and wind machine were stipulated to activate less than 2℃ during April of 2010. Orchard minimum temperature was elevated by sprinkler and wind machine compared to those of control when the temperature was less than 0℃; both treatments reduced approximately 50% frost damage of inflorescence and increased two times fruit set compared to the control. Trees treated by sprinkler and wind machine produced approximately 50% uniform fruit compared with 38% uniform fruit in control trees. Fruit setting degree of uniformity was 2 times higher at the control trees than those of the sprinkler? and wind machine-treated trees, which indicated that the control trees had lack of uniformity of the fruit setting degree, mostly due to the severe frost damage of the flusters.