자연 시효 처리된 AA 2026의 고온 노출에 따른 물성 열화 특성에 대한 연구

김하늘,강현우,장병록,김희국 한국열처리공학회 2024 熱處理工學會誌 Vol.37 No.3

AA 2026, which is used as an aviation material, is an improved version of 2024 and has higher physical properties, and is a material that has the potential to be applied to supersonic aircraft to be developed in the future. However, when an aircraft exceeds supersonic speeds, the surface heats up and the material must be resistant to this. Therefore, this study confirmed the high-temperature properties of AA 2026, an aviation structural material. AA 2026, solution treated at 500℃ for 4hr, was naturally aged at room temperature for more than 168 hr. Changes in microstructure and physical properties were confirmed over several hours of exposure to 100℃, 200℃, and 300℃, respectively. As a result of microstructure analysis, there was no significant change at 100℃, and from 200℃, GPB, a strengthening mechanism, grew and formed an S Phase. It was confirmed that the S Phase grew as the exposure time increased. Through a tensile test, it was confirmed that physical properties deteriorated as the precipitates grew. However, it was confirmed that the properties were stably maintained at 100℃, which is the temperature when the speed of a supersonic aircraft is less than Mach 2.

朝鮮後期 眞景山水畵 硏究 –謙齋 鄭歚派를 中心으로

김하늘 조선대학교 문화예술산업연구소 2023 문화예술산업연구 Vol.23 No.2

Sansu painting has undergone countless changes and developments from whales to modern times. Korea's landscape paintings, which have been developed under the influence of China, achieved rapid independent development in the late Joseon Dynasty, generally referred to as the Jingyeong period. Korea's pictorial originality is often mentioned in the expression ‘Jingyeong’. This may be because it captures the appearance of Korea's mountain stream expressed based on the actual scenery with a subjective perspective. In this paper, we would like to revisit the meaning of Jingyeong by examining the concept of ‘Jingyeong Sansu Painting’ and works focusing on the derived Jeong Seon. 산수화는 고래로부터 현대에 이르기까지 무수한 변화와 발전을 거듭하여 왔다. 중국의 영향을 받으며 발전하여온 우리나라의 산수화는 일반적으로 진경시대라고 일컫는 조선 후기에 비약적인 독자적 발전을 이루었다. 우리나라의 회화적 독창성은 ‘진경(眞景)’이라는 표현으로 자주 언급된다. 실경(實景)을 바탕으로 표현 되어진 우리나라 산천의 모습을 주관적 시선으로 담아내었기 때문일 것이다. 이는 관념의 테두리에서 벗어난 새로운 의식의 태동을 의미하며 독창적 시각이 반영된 화면을 구성하는 계기가 되었다. 본 논문에서는 이러한 ‘진경산수화’의 개념과 겸재 정산파를 중점으로 한 작품들을 살펴보며 진경에 대한 의미를 다시 알아보고자 한다.

한국 MCN(Multi Channel Network) 기업들에 대한 연구: 자원기반이론과 SWOT 분석을 중심으로

김하늘,이해수,박만수 사이버커뮤니케이션학회 2018 사이버 커뮤니케이션 학보 Vol.35 No.4

This research examined the core resources of each company from a resource-based view, and conducted SWOT analysis to analyze the outward form of the MCN industry, for the purpose of examining the landscape of the media industry ecosystem after the emergence of MCN. The results of analysis of Afreeca TV, Treasure hunter, Sandbox Network, and Dia TV showed that MCNs has similarities in that they are largely focusing on BJ education for contents integrity and cultivation of BJs(creators), while at the same time developing commerce for stable operation of profits and attempting to enter into TV media to increase their market and the number of MCN users. On the other hand, each company was creating strategies utilizing their core resources, and searching for ways to promote growth of the size of the MCN industry while at the same time making a living. However, the size of the pie for the industry is small which does not allow economies of scale to be realized, so some of company has the difficulty when it comes to finances. Despite this, each MCN shared the common idea that continued investment and effort is required to increase industry size. Therefore, through the results that were revealed in this research, we hope that it can establish a foundation for Korean MCN industry research, and that it can become basic data that can be referenced by each company to find methods to coexist. 본 연구는 MCN의 등장 이후 변화된 미디어 산업 생태계의 지형을 살펴보기 위해 자원기반관점에서 각 기업의 핵심 자원을 살펴보고, MCN 산업의 외연을 분석하기 위해 SWOT 분석을 시도하였다. 아프리카 TV, 트레져헌터, 샌드박스 네트워크, 다이아 TV를 분석한 결과, MCN은 크게 콘텐츠 건전성을 위한 BJ (크리에이터) 교육 및 BJ를 육성하는 데에 역량을 집중하고, 수익을 안정적으로 운영하기 위해 커머스 개발을 시도하는 한편, 시장을 키우고 MCN 이용자를 늘리기 위해 TV 매체로 진출을 시도하는 등 공통점을 발견할 수 있었다. 반면각 기업은 보유한 핵심 자원을 활용해 전략을 세우고 MCN 산업 규모의 성장도 모와 동시에 각자도생의 방법을 강구하고 있었다. 하지만 산업의 파이가 작아 규모의 경제가 실현되지 못해 각 기업들 중 일부 기업은 재정에 어려움을 겪고 있었다. 그럼에도 각 MCN은 산업의 규모를 키우기 위해서 꾸준한 투자와 노력이 필요하다는 문제의식을 공유하고 있었다. 따라서 연구로 밝혀진 결과를 통해 한국 MCN 산업 연구의 초석을 마련하고, 각 기업이 공존할 수 있는 방안을 모색하기 위해 참고할 수 있는 기초 자료가 되기를 기대해본다.

고압 분사용 인젝터의 니들 반응속도에 따른 노즐내부 유동특성 연구

金하늘,李海喆,車京玉 明知大學校 産業技術硏究所 2005 産業技術硏究所論文集 Vol.24 No.-

The PIEZO injector can be operated from high pressure above l800bar, It has a higher driven-efficiency than the existing solenoid-injector. Moreover the atomization of diesel fuel, that is injected by high pressure, can be improved in the engine cylinder. A fast response of needle is carried by the characteristics of piezo-electric actuator in PIEZO injector. In this study, a behavior analysis of the internal flow inside nozzle with a response velocity of needle performed by the numerical method-moving mesh. Before a unsteady analysis, it preceded a steady analysis and a measurement of the fuel injection rate. Also, two results were compared and verified with each other. The unsteady analysis used two result data with fundamental data of an analysis. And The 3-D geometry for numerical model was considered by the central cross-section regarding of one injection hole. As a result of unsteady analysis, it was found that a fast response of needle was occurred a high velocity and pressure of injection. Also, a flow of high velocity is distributed with a wide section.

선형 프레넬 반사판 태양열 발전시스템의 설계 및 제작

김하늘,김종규,Kim, Haneol,Kim, Jongkyu 한국교통대학교 융복합기술연구소 2018 융ㆍ복합기술연구소 논문집 Vol.8 No.1

In this study, design and manufacture of LFR (Linerar Fresnel Reflector) system was performed for solar thermal absorption cooling. The LFR system was designed considering the expansion and convenience to be installed according to the cooling capacity of the applicable building. Twelve LFR modules with a total reflection area of $204m^2$ were installed. The automatic tracking system was applied to track the sun during the daytime.

귤피를 활용한 저열량 앙금 고로케 제품의 개발

김하늘,김다영,진수성,이다빈,김태완 한국식품영양과학회 2022 한국식품영양과학회 학술대회발표집 Vol.2022 No.10

Controlled transdermal drug release system triggered by visible light irradiation

김하늘,성금용,양승윤,윤진환 한국고분자학회 2015 한국고분자학회 학술대회 연구논문 초록집 Vol.2015 No.4

내 사랑은 고딕체예요 외 2편

김하늘 고요아침 2017 열린시학 Vol.22 No.1

Preparation of light-responsive hydrogels and their application on drug release system

김하늘,이현진,이은수,윤진환 한국고분자학회 2014 한국고분자학회 학술대회 연구논문 초록집 Vol.2014 No.4

일 감염병 전담병원 간호사의 COVID-19 관련 직무스트레스, 감정노동, 임파워먼트가 재직의도에 미치는 영향

김하늘,양승애 한국사물인터넷학회 2022 한국사물인터넷학회 논문지 Vol.8 No.6

This study aims to identify the degree of job stress related to COVID-19, emotional labor, empowerment, and retention intention of nurses in hospitals dedicated to infectious diseases, and confirmed the effect of job stress related to COVID-19, emotional labor, and empowerment on retention intention. The data collection of this study was conducted from August 27, 2021 to September 17, 2021 through a structured questionnaire targeting 162 nurses at an infectious disease hospital in S city. The data were analyzed analyzed using frequency and percentage, mean and standard deviation, t-test, ANOVA, Pearson's Correlation Coefficient, and multiple linear regression using SPSS/WIN 25.0. As a result of analyzing differences according to general characteristics, retention intention showed a significant difference according to work department and work satisfaction. And as a result of analyzing the correlation between retention intention and COVID-19 related job stress, emotional labor, and empowerment, it showed a significant negative correlation (r=-0.215, p=0.006) with job stress related to COVID-19 and a significant positive correlation (r=0.343, p<0.001) with empowerment. As a result of multiple linear regression analysis, job satisfaction, job stress related to COVID-19, and empowerment were identified as significant variables affecting retention intention (F=23.751, p<0.001), and the explanatory power was 30.0%. Through the above results, we intend to provide basic data for strategic development for efficient nursing manpower management. 본 연구는 일 감염병 전담병원 간호사의 COVID-19와 관련된 직무스트레스, 감정노동, 임파워먼트 및 재직의도정도를 파악하고 COVID-19와 관련된 직무스트레스, 감정노동, 임파워먼트가 재직의도에 미치는 영향을 확인하고자한다. 본 연구의 자료수집은 S시 소재 감염병 전담병원 간호사 162명을 대상으로 구조화된 설문지를 통해 2021년 8월27일부터 2021년 9월 17일까지 실시하였고, SPSS/WIN 25.0을 이용하여 빈도와 백분율, 평균과 표준편차, 독립표본t-검정, 분산분석, 피어슨상관계수, 다중선형회귀분석을 이용하여 분석하였다. 일반적 특성에 따른 차이 분석 결과 재직의도는 근무부서 및 근무만족도에 따라 유의한 차이가 나타났고, 재직의도와 COVID-19와 관련된 직무스트레스, 감정노동, 임파워먼트간의 상관관계를 분석한 결과 재직의도는COVID-19와 관련된 직무스트레스와 유의한 부적 상관관계(r=-0.215, p=0.006)를 나타냈고 임파워먼트와 유의한 정적 상관관계(r=0.343, p<0.001)를 보였다. 다중선형회귀분석결과 재직의도에 영향을 미치는 유의한 변수로 근무만족도, COVID-19와 관련된 직무스트레스, 임파워먼트가 확인되었으며(F=23.751, p<0.001) 설명력은 30.0%이었다. 이상의 결과를 통해 효율적인 간호인력 관리를 위한 전략개발의기초자료를 제공하고자 한다.