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Prolonged Turbidity of the Lower Nakdong River in 2003

  • Kim, Dong-Kyun;Kim, Hyun-Woo;Kim, Gu-Yeon;Kim, Young-Sang;Kim, Myoung-Chul;Jeong, Kwang-Seuk;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.38 no.spc
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    • pp.44-53
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    • 2005
  • The Nakdong River, which lies in a monsoon climate zone with warm rainy summers and cold dry winters, is a typical ecosystem showing the attributes of a regulated river. In 2003, the total annual rainfall (1,805 mm) was higher than the average of the past nine years from 1994 to 2002 (1,250 mm). In September a powerful typhoon, Maemi, caused a big impact on the limnology of the river for over two months. Among the limnological variables, turbidity in 2003 (37.4 ${\pm}$ 94.1 NTU, n = 54) was higher than the annual average for ten years (18.5 ${\pm}$ 2.3 NTU, n = 486) in the lower part of the river (Mulgum: RK 28). Furthermore, physical disturbance (e.g. stream bank erosion within channel) in the upstream of the Imha Dam (RK ca. 350; river distance in kilometer from the estuary barrage) in the upper part of the river was a source of high turbidity, and impacted on the limnological dynamics along a 350 km section of the middle to lower part of the river. After the typhoon, high turbidity persisted more than two months in the late autumn from September to November in 2003. Flow regulation and the extended duration of turbid water are superimposed on the template of existing main channel hydroecology, which may cause spatial changes in the population dynamics of plankton in the river.

The Study on the Multiple Intelligence Aptitude, Career Tendency & Career Maturity of Verbal Writing Gifted Student (초등학교 언어창작영재의 적성과 진로성향 및 진로성숙도 연구)

  • Kim, Yoo-Seon
    • Journal of Gifted/Talented Education
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    • v.21 no.1
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    • pp.141-161
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    • 2011
  • This study have an intention of identifying multiple intelligence aptitude, career tendency and career maturity of verbal writing gifted students. 60 verbal writing gifted students who have achieved success in the writing contest were collected for this study. The data was selected through survey MI instruments from the students. The results are summarized as follow. First, verbal writing gifted students' MI profiles were revealed that linguistic intelligence, musical intelligence were strong, and logicalmathematical intelligence was weak. Second, many verbal writing gifted students showed strong musical career aptitude and strong linguistic career aptitude but few writing gifted students showed strong logical-mathematical aptitude. It was revealed that logical-mathematical interest had significant relationship with logical-mathematical achievement in the p-value<.01. Third, there were many linguistic career tendency students & interpersonal career tendency students. But there was no naturalist career tendency student. Musical career tendency, naturalist career tendency showed big differences between strong career aptitude and career tendency. Fourth, career maturity of verbal writing gifted student was very high. The finding can be explained that most of them have characteristics of early career maturity. Parents, teachers, specialists have to provide career information matching strong aptitude and aptitude improving education matching career tendency to the verbal writing gifted students to choose their career successfully.

Comparison of the Consciousness of One's Body Between Oneself and Other People (체형에 대한 자기의 인식과 타인의 인식 비교)

  • Lee, Jeong-Yim;Nam, Yun-Ja
    • Fashion & Textile Research Journal
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    • v.5 no.4
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    • pp.372-378
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    • 2003
  • The purpose of this study is to compare the self consciousness of one's body cathexis with other people's. The sample subjects were 97 females between 18 and 24 years old. They were measured on November 1999 with the anthropometric measuring, and their front and side photographs were taken. First, we investigated the size recognition of 5 body parts and ready-made clothing, the consciousness of the size of 5 body parts and body proportion for subjects. Second, we organized panel group consisted of 30 females in twenties majoring the Clothing & Textiles. The consciousness of panel group to the subject's body proportion was investigated by using the front and side photographs of subjects, and was compared with self consciousness of subjects. Data were analyzed by frequency analysis and correlation analysis. Most of subjects recognized their status, bustgirth and waistgirth larger than their real size, but they recognized their hipgirth smaller than their real size and their weight similar to their real weight. And subjects were conscious of their status and bustgirth small, their weight, waistgith and hipgirth proper or a little big, and their body proportion normal or a little unbalanced. The self consciousness of one's body cathexis was related to heights of each part especially, and subjects had a tendency to appreciate their body proportion positively if they recognized themselves tall and thin. Upon comparison of the consciousness of subject's body between subjects themselves and panel group, the appreciation of panel group was better than those of subjects themselves. And we also certified the difference of consciousness of one's body cathexis between oneself and other people. The consciousness of other people was related to the size of each body part, but the self consciousness was predicted that it was more related to the psychological factor including satisfaction or preference.

A Study on the Behavior of Metal Touch Connection subject to Connection Types (이음방식 및 틈의 위치에 따른 메탈터치 이음부의 거동에 관한 연구)

  • Hong, Kap Pyo;Kim, Seok Koo
    • Journal of Korean Society of Steel Construction
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    • v.16 no.5 s.72
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    • pp.661-669
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    • 2004
  • In the steel structure of high-rise buildings, a connection analysisand a column design have been made after welding and bolting suitable gaps. Each country, however, has different codes, and such differences are very big. American steel has been designed according to a code that all axial loads can be carried from the upper parts to the lower parts as determined by the designer, but Korean and Japanese steel have been designed by 1/4 of the standard of all axial loads. In this paper, a metal touch experiment was done as an intermediation parameter with a connecting location and a connecting method for economic and constructive efficiency. Every specimen is tested by a low-to-high displacement control to grasp ultimate strength, displacement, the connection's lateral deflection, and stress. The results of the test were compared and analyzed.

Development of an Automatic Soil Hardness Measuring System Mountable on Agricultural Tractors (트랙터 부착형 자동 토양경도 측정 시스템 개발)

  • 이현동;김기대;김찬수;김성환
    • Journal of Biosystems Engineering
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    • v.27 no.6
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    • pp.537-546
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    • 2002
  • In this study an automatic soil hardness measuring system mountable on agricultural tractors was developed to improve the accuracy of manual soil hardness testers by a constant penetrating rate, right direction of the cone-penetrometer and the isolation of vibration from the operator. This was necessary to supply similar experimental condition for performance test of new model and comparative experiment. The results of the study are summaried as follows; 1. The system consisted of a sensing part of soil hardness, a driving part of the measuring system and an attaching part between the tractor and the measuring system. 2. The allowable limit value of the system developed was set to 392N to protect from breaking the serve motor and the coupling used in this system. 3. The driving shaft penetrated into soil by 0.3m to measure soil hardness. The soil hardness was measured at the depth of 0.3m from the soil surface but the penetrating work was stopped and the driving shaft was pulled out to protect the system when the value of the soil hardness was too big on foreign substances like stones or straws. 4. Two values measured by automatic measuring system developed in this research and manual penetrometer were compared by statistics hypothesis testing method. When two people measured the soil hardness at the depth of 0.1 and 0.15m by manual cone penetrometer, there was no relationship between two values by two people but the values at the same depths by automatic measuring system developed showed similarity. The automatic system, therefore, developed in this research was proper for measuring soil hardness.

Principles and Methods for Critical Mathematics Education: An Explorative Study of a Program (비판적 수학교육의 원리와 방법 탐색: 프로그램 개발을 위한 기초연구로서)

  • Song, Ryoon-Jin;Ju, Mi-Kyung
    • Journal of Educational Research in Mathematics
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    • v.27 no.4
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    • pp.857-888
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    • 2017
  • Due to globalization, diversification, and informatization, modern society confronts change and crisis in a variety of areas such as economy, politics, and culture. In that context, mathematics educators seek for how to reform school mathematics for democratic and just society. This research proposes critical mathematics education as an alternative model of school mathematics for democratic society. In particular, this research is an explorative study to construct a model of critical mathematics education program. For the purpose, we conducted a comprehensive literature review to identify goals, contents, and methods of teaching and learning, and method of assessment for critical mathematics education. We checked the validity of the model by using the cases of critical mathematics education. Since this research is explorative in the regard that the model is based on theoretical literatures, further research is necessary to extend the model through design research in school context.

A study on Regional foods in the middle of Chosun Dynasty through Domundaejac ("도문대작(屠門大嚼)"을 통해 본 조선중기 지역별 산출 식품과 향토음식)

  • Cha, Gyung-Hee
    • Journal of the Korean Society of Food Culture
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    • v.18 no.4
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    • pp.379-395
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    • 2003
  • Regional foods is influenced by weather, local and social environment etc. The purpose of this study was to understand that regional foods in the middle of Chosun Dynasty through Domundaejac. Some of representative dishes of the Hansung and Kyonggi-do Area is duck(rice cake) of seasonally celebrated days, hangua(korea confectionary) and rice wine. Typical foods in Chungchong-do Area is included persimmon, jujube, watermelon and wax gourd. Some of the well-known food in Kangwon-do Area is pear, bangpungchuk(gruel), sukebyung(rice cake), woongjijunggua(korea confectionary) and sanat-kimchi(picked mustard leaves and stem) that is seemed characteristics of mountainous section. Some of the famous dishes in Cholla-do Area is backsanja(korea confectionary), tea, chuksun kimchi(bamboo shoot pickle), citrus fruits and ear shell. Kyongsan-do Area ia famous persimmon, bamboo fruit, dasik(korea confectionary) and yakban(glutinous rice cake). Hwanghae-do Area is famed pear and choshi as assumed the eatly form of gochujang(thick soypaste mixed with red pepper). Representative dishes are deljjuk(blue berry), herring, sangat-kimchi(picked mustard leaves and sterm) in Hamgyong-do Area and daemandu(big dumpling) in Pyongan-do Area. The coast area is famous for using lots of sea food. Fresh seafood is consumed raw, and clams, fish and seaweed are liberally added to soups and other dishes. The East coast is catched salmon, flatfish, codfish, sandfish and mackerel The West coast is catched yellow corvenia, lobster, tiny shrimp and large-eyed herring. The South coast is catched sea mussel, codfish and laver.

Rolling Contact Fatigue and Residual Stress Properties of SAE52100 Steel by Ultrasonic Nano-Crystalline Surface Modification (UNSM) (초음파 나노표면 개질처리를 통한 베어링강의 회전접촉피로 및 잔류응력 특성에 대한 연구)

  • Lee, Changsoon;Park, Ingyu;Cho, Insik;Hong, Junghwa;Jhee, Taegu;Pyoun, Youngsik
    • Journal of the Korean Society for Heat Treatment
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    • v.21 no.1
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    • pp.10-19
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    • 2008
  • To investigate the effect of ultrasonic nano-crystalline surface modification (UNSM) treatment on rolling contact fatigue and residual stress properties of bearing steels, this paper carried out a rolling contact fatigue test, measured residual stress and retained austenite, performed a wear test, observed microstructure, measured micro hardness, and analyzed surface topology. After the UNSM treatment, it was found that the surface became minute by over $100{\mu}m$. The micro surface hardness was changed from Hv730~740 of base material to Hv850~880 with about 20% improvement, and hardening depth was about 1.3 mm. The compressive residual stress was measured as high as -700~-900 MPa, and the quantity of retained austenite was reduced to 27% from 34%. The polymet RCF-6 ball type rolling contact fatigue test showed over 4 times longer fatigue lifetime after the UNSM treatment under 551 kgf load and 8,000 rpm. In addition, this paper observed the samples, which went through the rolling contact fatigue test, with OM and SEM, and it was found that the samples had a spalling phenomenon (the race way is decentralized) after the UNSM treatment. However, before the treatment, the samples had excessive spalling and complete exploration. Comparison of the test samples before and after the UNSM treatment showed a big difference in the fatigue lifetime, which seems to result from the complicated effects of micro particles, compressive residual stress, retained austenite, and surface topology.

Earnings Management Associated with Types of CEO Turnover in Public Institutions (공공기관의 경영자 교체유형과 이익조정 행태와의 관련성)

  • Jang, Ji-Kyung
    • The Journal of the Korea Contents Association
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    • v.17 no.1
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    • pp.213-221
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    • 2017
  • This study examines the influence of CEO(Chief Executive Officer) turnover on earnings management in public institutions. We classified sample into four portfolios based on the joint types of departing CEO(Forced/Voluntary) and incoming CEO(Expert/Nonexpert), and we explore whether earnings management are distinguishable depending on the types of CEO turnover. Empirical findings are summarized as following. The different patterns of earnings management are observed for each portfolio in the turnover year. In particular, when departing CEO leaves the company forcibly and incoming CEO is an expert in that business, there is an evidence of downward earnings management in the turnover year. This means that the incoming CEO takes a bath in his first year by recording big charges to shift blame for failed management on to the predecessor. The results documented in this paper provide an important implication for diverse interest groups participating in the CEO turnover decisions at the present time when normalization of management of public institutions is viewed more important than ever.

The Comparison of the Color Perception between the Korean and the Japanese undergraduates (한일 대학생의 색지각에 대한 비교연구)

  • ;;都築和代
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.3
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    • pp.1-6
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    • 1998
  • The purpose of this study was to investigate the scope of color perception for Japan standard color. In addition to, we compared the difference in the color perception between the Korean and the Japanese undergraduates. 140 male and 119 female Japanese undergraduates were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Metre CR 300 was used for physical measurement of the color. The results were as follows, 1) Japanese students' perceived color perception was classified into four large groups: simple group includes Red, Yellow, Blue, White, Gray and Black, X(-axis)group includes Green, Red Purple, Y(-axis)group includes Green, complex group includes Blue Green, Purple, Purple Blue, Red Purple. 2) There is difference between Korean color perception and Japanese; for Yellow Red, Blue, Blue Green, Red Purple. 3) There is little difference between the values of standard color and mean percept color for Yellow while big difference for Blue. And as for as country was concerned, Korean is more accurate than Japanese in color perception.

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