점탄성 유체의 용융방사공정의 동특성 1 . 정상상태의 방사사선의 거동

김주환,김병민,이상헌,유병규,현재천 ( Joo Hwan Kim,Byung Min Kim,Sang Heon Lee,Byung Kyu Yoo,Jae Chun Hyun ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.5

Dynamic characteristics of melt spinning, the most important process in synthetic fibers manufacturing, has been investigated by conducting a simulation. The governing equations of one-dimensional model comprising the continuity equation, the equation of motion, the energy equation, and the constitutive equation of the materials, have been solved for different material constants and different operating conditions to find out the effect of the industrially important operating variables on the spinline dynamics. This kind of prediction through a simulation provides valuable information to the productivity improvement of melt spinning, i.e., process stability and product quality. Specifically, in this study we evaluated how the spinning process is influenced by the characteristics of viscoelastic fluids and the operating conditions such as spinning velocity, cooling conditions, spinning distance, and so forth.

해운선사 안전관리 평가지표 개발에 관한 연구(2) : 안전경영 지표 평가항목 개발

김주환,김화영,Kim, Joo Hwan,Kim, Hwa Young 해양환경안전학회 2015 해양환경안전학회지 Vol.21 No.6

본 연구는 '해운선사 안전관리 평가지표 개발에 관한 연구'의 후속연구로서 선행연구에서 도출한 '안전관리 평가지표'의 '안전가점' 지수에 해당하는 안전경영 지표의 평가항목을 개발하고, 적정성을 평가하는데 목적이 있다. 이를 위해 해상화물운송사업장에서 일하는 안전관리 담당자를 대상으로 의견을 수렴하여 안전경영 지표별 11개의 평가항목을 개발하였다. 식별된 11개 평가항목에 대한 적정성 검토를 위해 설문조사를 실시하고, 사업형태별(내항해상화물운송, 외항해상화물운송), 사업규모별(보유선박수)로 응답자의 적정성 인식의 차이를 통계적 기법을 활용하여 분석하였다. 그 결과, 평가항목에 대한 적정성 인식의 차이는 사업형태와는 무관하였다. 그러나 사업규모에 따라서는 소(小) 중(中) 대(大) 3개의 그룹 간 평가항목의 적정성에 인식의 차이가 존재했다. 따라서 향후 안전경영 지표를 활용하여 선사를 평가할 경우, 사업형태별로 동일하게 평가하되 사업규모별로는 보유선박수에 따라 그룹화하여 평가하는 것이 타당하다는 결론을 얻었다.

Optimal Weights of Linear Combinations of the Independent Poisson Signals for Discrimination

김주환,Kim, Joo-Hwan The Korean Data and Information Science Society 2002 한국데이터정보과학회지 Vol.13 No.2

Suppose one is given a vector X of a finite set of quantities $X_i$ which are independent Poisson signals. A null hypothesis $H_0$ about E(X) is to be tested against an alternative hypothesis $H_1$. A quantity $$\sum\limits_{i}\omega_ix_i$$ is to be computed and used for the test. The optimal values of $\omega_i$ are calculated for three cases : (1) signal to noise ratio is used in the test, (2) normal approximations with unequal variances to the Poisson distributions are used in the test, and (3) the Poisson distribution it self is used. A comparison is made of the optimal values of $\omega_i$ in the three cases as parameter goes to infinity.

한탄강(漢灘江) 일대(一帶)의 지표기복(地表起伏)에 관한 정보(情報)

김주환,Kim, Joo-Hwan 한국동굴학회 2006 동굴 Vol.72 No.-

The purpose of this study is to clarified the geology and geomorphic characteristics of the Hantan River Basin. In this area, some kind of landforms are developed such as pre-land forms, lava plateau, and present landforms etc. Some river terraces are peculiar features in the area. Some conclusions are as follows : The vicinity of the Hantan River is lava plateau formed from the volcanic activity. Some steptoes are located in the lava plateau. Baekeuiri formation means the river bed boulder beneath the lava formation. The development of drainage patterns are unstable and the bifurcation ratio, the ratio of mean length of the river are lower than the other rivers. The relative height of the terraces is about $5{\sim}25m$ and the terraces are alluvial terraces. In the Jiktang Fall area, bedrock is granite and basalt plateau covered the bedrock. In that point, the old erosion surface is relatively steeper than the horizontal-basalt plateau. Vertical columnar joints are developed and weathering materials creep on the valley wall. The cross section of the landform of the Kosukjung vicinities are somewhat different from the landforms of Jiktang Fall. The bedrock near the Kosukjung is granite that is the same with the Jiktang Fall. But the cross section shows a asymmetrical curve from each side.

직탕폭포와 고석정 주변의 지형

김주환(Kim Joo Hwan) 한국사진지리학회 1997 한국사진지리학회지 Vol.5 No.1

The purpose of this study is to explain the formation of present landforms of the Jiktang Fall and Kosukjung area. In the Jiktang Fall area, bedrock is granite and basalt plateau covered the bedrock. So the cross section of the Jiktang Fall (Fig.24) shows that the relationship between bedrocks and plateau. Near the point A means the very contact of basalt and granite outcrops. In that point, the old erosion surface is relatively steeper than the horizontale-basalt plateau. Near the B point, vertical columnar joints are developed and weathering materials creep on the valley wall. Upper part of the C point, the head of columnar joint are scattered all around the riverbed. On the D paint is similar to the outcrop B. The cross section of the landform of the Kosukjung vicinities are somewhat different from the landforms of Jiktang Fall. The bedrock near the Kosukjung is granite that is the same with the Jiktang Fall. But the cross section shows a asymmetrical curve from the point A to D. Near the point A, the horizontal basaltic plateau represents the plain surface and the weathering materials form soils. Point B is very contact between basaltic plateau and erosion surface. And vertical columnar joint are well developed. Point C is a granitic bedrock located in the middle of the river and some part of it tafonis are formed. Point D is a old erosion surface consist of fresh granite and lots of joint sets and groups are well developed.

사진예술가의 정신

김주환(Kim Joo Hwan) 한국사진지리학회 1998 한국사진지리학회지 Vol.7 No.1

It is very difficult to clarify the definition of arts. The definition, production and the activities of the art is somewhat metaphysical and theoretical problems. The purpose of this study is to summarized the concepts and definitions, activity of the arts, photography related to arts and mind of photoartists. Art is a conscious human activity of either reproducing thing, or constructing forms, or expressing experience, if the product of this reproduction, construction, or expression is capable of evoking delight, or emotion or shock. It is evident that the concepts of a piece of work as man-made manufactured articles. There are two categories to express the production of arts. One is representation and the another is expression. Representation means the description of the environment. And the meaning of the expression is the express the thought remaining in the heart. And it is hard to explain the good photo. And the basic characteristics of the art is the interpretation of the values related to the interest, relation and objects. In the mind of photoartist it is necessary to recognize that the artist belong to the nature. The culture of the mankind begins endless correlationship between the man and the nature. There are three kind of the relationship between man and the nature, for example, man over the land, man with the land and man under the land. To the photoartist, the understanding of the relationship between man and man, and the man and the historical idea is required as a moral excellences. On the foundation of the above item, it is better to the photoartist whose characters are composed of free independent, refinement and harmonious ideas.

칠갑산 지형경관 자원의 분포와 특징

김주환 ( Joo Hwan Kim ),김태석 ( Tae Suk Kim ) 한국사진지리학회 2010 한국사진지리학회지 Vol.20 No.4

The area in the study has the geomorphological feature in which the ridge and river are developed in a radial shape from the highest peak, Mt. Chilgap (559.7m high). According to the site survey, geomorphological landscape resource comprises the joint, periglacial landform and rivers terrain. The joint developed on outcrop of the rock is viewed in horizontal shape, vertical shape, cross shape, irregular shape and curve shape. And in periglacial landform, talus and the slope behind the rock and the separated block are viewed. When it comes to rivers terrain, the cliff and cave developed by stream erosion and wetland were distributed. Mt. Chilgap has more diverse geomorphological features than other mountains in Midwest region with a good accessibility which is valuable for student`s learning.

PIE와 GPA에 관한 연구

김주환 ( Joo Hwan Kim ) 한국사진지리학회 2009 한국사진지리학회지 Vol.19 No.4

The purpose of this study is preparing the idea that is much helpful for the teaching of geography. PIE (Photo In Education) means the photo activities in education, and through the photography, PIE intend to improve the abilities of writing and visual language education. GPA means the Geo-Photo-Artist. GPA characterized as a man of geographer, photographer and artist. It is certain that the GPA who teachs the geography and apply the photography, the geography teaching will be better soon.

불암산(佛岩山) 지역(地域)에 발달(發達)한 제미지형(諸微地形)

김주환 ( Joo Hwan Kim ) 한국사진지리학회 2006 한국사진지리학회지 Vol.16 No.2

고등학교 문학 수업에서 토의 학습의 효과

김주환 ( Joo Hwan Kim ) 청람어문교육학회 2012 청람어문교육 Vol.46 No.-

This study aimed to investigate the effects of discussion-based lessons in high school literature classes. For this purpose, in high school literature classes, this study set two classes; discussion-based class vs. explanation based class. After two weeks of lessons, a general language arts exam and a survey for students` satisfaction were implemented for both classes. This study found out that the discussion-based lessons had the statistically significant effects for high school literature classes, for both scores of language arts exam and the level of satisfaction. Compared to the students of the explanation-based class, the students of the discussion-based class received higher scores from the language arts exam. In addition, in the satisfaction survey, the discussion class students show more positive responses than negative ones. This study also identified and discussed that many factors, such as group-organization, reading text selection, instruction models, are critical for successful discussion-based lesson.