태평양 심해저 망간단괴의 조직 및 광물학적 연구

김대철,박맹언 한국수산학회 1987 한국수산과학회지 Vol.20 No.4

태평양 심해저로부터 채취된 망간단괴는 미세구조의 특징을 기준으로 하여 세가지 유형(Type A, B 및 C)으로 분류되며, 이들 미세구조들은 단일 단괴에서도 혼합구조로서 흔히 산출된다. 각 유형은 상이한 화학성분과 구성광물 및 결정도를 나타내며 이 중 A형은 조립질 조직을 갖고있고 다른 유형에 비해 결정도가 높은 Todorokite로 주로 구성되고 Mn의 함량도 높은 반면에 B와 C형은 중간 내지는 세립질 조직을 갖고 있다(Mn=30.6%). 또한 A형은 상대적으로 빠른 성장속도를 나타내며, 보트리오이드 사이의 공극에서 Smectite와 규질화석이 나타난다. 이러한 특징을 A형 구조를 갖는 미세한 층(micro layer)의 성인이 해저에서의 열수작용과 관련된 것으로 생각되며. 열수용액은 주변 단열대와 해저확장대로부터 공급된 것으로 추정된다. Texture and mineralogy of different microlayers of deep-sea manganese nodules are investigated to reveal the environmental changes of nodules during a nodule formation. Basieally a nodule can have three types (A, B and C) of microlayer. Some nodules show only one or two types of microlayer. The classification is based primarily on the texture. The surface texture of type A is coarsely porous globular microstructure whereas type B and C are intermediate to finely porous textures. The type A is characterized by its highest Mn content (30.6%) and relatively well-crystallized todorokite as well as the rapid growth rate. Smectite and biogenic silica (radiolaria) are also easily observed in the type A layer. It appears that the hydrothermal activity is one of the favorable mechanism of formation for the type A layer. The hydrothermal solution is possibly supplied from nearby fracture zone and spreading center.

Phase Transition in Mixtures of Diblock Copolymer and Random Copolymer

김대철,진왕철 한국고분자학회 1998 한국고분자학회 학술대회 연구논문 초록집 Vol.1998 No.4

패스트푸드 레스토랑의 효율적 운영방안

김대철,장미향 한국호텔리조트학회 2012 호텔리조트연구 Vol.11 No.3

This study is about comparison of job allocation policies for fast food restaurants. The objectives of the study are to minimize the waiting times of customers in a queueing line and to maximize the revenue of fast food restaurants. Two job allocation polices are considered. To analyze these two job allocation policies under various business conditions, system simulation method is applied. Simulation models are developed using ARENA simulation language. To measure the performance of the policies considered, average waiting times in queue and total number of customers served for simulation time horizon are used. The results show that the combined job policy performs better than the serial job policy under same conditions. If learning effects are allowed for the serial model, in some conditions, the serial one works better than the combined in terms of total served customers. But the combined one still shows superiority to the serial job policy from the waiting time prospective.

누적손상이론을 이용한 기계류부품의 가속수명시험법 개발

김대철,이근호,김형의,Kim, Dae-Cheol,Lee, Geun-Ho,Kim, Hyeong-Ui 한국기계연구원 2002 硏究論文集 Vol.32 No.-

This study was performed to develop accelerated life test method of machanical parts using cumulative damage theory that used to model the fatigue of parts that receive variable load. The cumulative damage theory was introduced, and the estimation of life and calculation of accelerated life test time was illustrated. As the actual application example, accelerated life test method of agricultural tractor transmission was described. Life distribution of agricultural tractor transmission was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 3,000 hours and 90% reliability for one test sample. According to the cumulative damage theory, because test time can shorten in case increase test load, test time could be reduced by 482 hours when we put the load 1.1 times of rated load than 0.73 times of rated load that is equivalent load calculated by load spectrum of the agricultural tractor. This time, acceleration coefficient was 11.7. This accelerated test method was used to develop accelerated test method of gear reducer, hydraulic hose and bearing as well as agricultural tractor transmission and it is considered to be applied comprehensively to machanical parts the fatigue of which is happened by load or pressure etc.

SAG-M 적혈구 첨가액에 보관된 농축 적혈구의 수혈 후 생존능

김대철,임채승,김영기,이갑노,황유성,김두성,임춘수 大韓輸血學會 1997 大韓輸血學會誌 Vol.8 No.1

탄성파 축소모형 실험에서의 3D 프린팅 기술 활용

김대철,신성렬,정우근,신창수,임경민 한국자원공학회 2019 한국자원공학회지 Vol.56 No.3

The application of 3D printing technology in seismic physical modeling was investigated and the related domestic research was conducted. First, seven types of additive manufacturing methods were evaluated. In this report, to confirm the application of 3D printing technology, related studies in domestic and international journals of geophysics were searched and a comprehensive analysis was conducted according to year and the additive manufacturing type. The analysis showed that studies on 3D printing technology have been dominantly conducted since the 2010s, which corresponds to the time when 3D printers were commercialized. Moreover, 87% of the studies used the material extrusion additive manufacturing method, and the research was conducted in specific universities. This research can be used as basic data for application of 3D printing technology in geophysics. 탄성파 축소모형 실험에서의 3D 프린팅 기술 활용에 관하여 파악하였으며, 국내에서 수행되고 있는 연구를 서술하였다. 먼저 3D 프린팅 기술을 적층 방식에 따라 7가지로 분류하여 설명하였다. 3D 프린팅 기술 활용을 파악하 기 위하여 물리탐사 분야의 국내외 학술지에서 관련 연구를 검색하였고 관련 연구를 연도 및 3D 프린팅 적층 방식에 따라 종합적인 분석을 수행하였다. 분석 결과, 2010년대부터 연구가 수행되어 왔으며, 이는 3D 프린터의 상용화 시점 과 비슷한 것을 확인할 수 있었다. 또한 논문의 87%가 material extrusion 적층 방식을 활용하였으며, 수행된 연구들은 특정 대학에 집중되어 수행되었다. 본 연구 내용을 활용한다면 탄성파 축소모형 실험 분야에서 3D 프린팅 기술 활용 에 대한 기초자료로 사용될 수 있을 것으로 생각된다.

1P-132 Facile and Low-temperature, Solution-Processable Polymer Gate Dielectric for Thin Film Transistors

김대철,하영근 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

We demonstrate polymer gate dielectric material for cross-linking method. These film are fabricated via solution processes and had a low gate leakage current density(~10-6A/cm2). It had a high capacitance (30nF/ cm2) than silicon oxide. Also, These film had simple and low temperature fabrication procedure. These film preferred Thin-film transistors(TFTs) fabricated bottom contact top gate structure using organic semiconductors and inorganic semiconductors. These devices exhibit improvement of carrier mobility and on/off ratio.

2019년 지방세 관계법 개편방향

김대철 한국지방세연구원 2019 지방세포럼 Vol.48 No.-

가격할인에 따른 업무변화가 종사원의 직무만족과 이직의도에 미치는 영향

김대철,성혜진,이애리 한국외식경영학회 2007 외식경영연구 Vol.10 No.1

This study tried to examine and analyze the effect of the discount of the price on the employees’ task satisfaction and intention of turnover because the restaurant companies could not employ the adequate workers to the increasing numbers of the customers due to the policy of the discount of price. We selected 4 chain family restaurants in and around Seoul and distributed total 400 question sheets and after that, we had real analysis with 341 as the final effective samples. The result as follows : First, in the job alternation to price discount, the job satisfaction has significant effect on the ‘motivating factor’ and task liking has significant effect on both ‘motivating factor’ and ‘hygiene factor’ in the job satisfaction of employees.Second, job alternation to price discount has significant effect on all of ‘growth factor’, ‘psychology factor’, ‘economy factor’ and ‘management factor’ among the employee’s will of turnover intention and task liking has significant effect on ‘growth factor’, ‘psychology factor’ and ‘economy factor’ among the employee’s will of turnover intention.Third, in the motivating factor of the job satisfaction, the will of turnover intention of the employees has significant effect on ‘growth factor’, ‘psychology factor’, ‘economy factor’ and ‘management factor’ but task liking doesn’t have significant effect on all will of turnover intention of the employees.

시대에 적합한 농업기계 인재양성

김대철 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.2