• Journal of the Korean Society for Heat Treatment
• /
• v.9 no.3
• /
• pp.177-186
• /
• 1996

Surface alloying of Ti alloy by $CO_2$ laser is able to produce few hundred micrometers thick TiN or TiC surface-alloyed layer with high hardness on the substrate by injecting reaction gas($N_2$ or $CH_4$). Laser surface alloying by means of process control is in many applications essential in order to obtain predictable hardening layer. This research has been investigated the effect of such parameters on TiN and TiC gas alloying of Ti-6Al-4V alloy by $CO_2$ laser. The maximum surface hardness of TiN layer was obtained 1750Hv on the conditions of 0.8kW laser power, 0.8m/min scanning speed and 100% $N_2$ atmosphere. However, the maximum hardness of TiC formation layer after laser treatment was about 630Hv. As scanning speed was increased, the hardness and depth of these layers were decreased at constant laser power.

• Journal of the Korean Society of Food Culture
• /
• v.18 no.6
• /
• pp.515-526
• /
• 2003

The object of this study was to investigate the relationship between the eating habits of high(4th, 5th, 6th) grade elementary school students and parental behavior characteristics(affection, rational guidance, overprotect and neglect). The parenting behavior scale and demographic variables, eating habits and food frequency were administered to the subjects. In this investigation, the subjects were 396 boys and 337 girls in Chunju city in Korea, 50.1% of the mothers was in the age from 35 to 39 years and 57.8% of the mother had an occupation. Data were analyzed by using a SPSS PS package. Significant differences and correlation among variables were determined by the frequency, $x^2-test$ and pearson's correlation coefficient. Eating habits was significantly influenced by mother's employment status, but was not affected by the levels of mother's education and income. Parental behavior characteristics was significantly related to the children's snacks habits(p<0.05, p<0.01), but have no connection with dietary habits and the eating out. The survey revealed higher percentage of the children who had taken affectionate, reasonable and positively reinforced child care, answered they enjoy meals and the other groups answered they did not. Also frequency of having soup, green vegetables, fruits, dairy products had positive relationship with affective, reasonable rearing attitude, but negative relationship with neglective rearing attitude. And the survey showed children who were reared in overprotect had chocolate, candy and the like in large quantities.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.536-538
• /
• 2001

국내에서는 전력산업의 규제가 점차 완화되면서 전력시장은 새로운 틀이 형성되어지고 있다. 전력시장의 구조개편후 각 전력회사들은 그들의 판매수익을 높이기 위하여 행동하게 될 것이다. 즉 그들의 부하를 적절하게 조절함으로써 한계비용이 평균비용보다 낮게 유지되도록 하여 이윤극대화를 추구해 나갈 것이다. 따라서 전력회사들은 수요측의 관리가 과거 어느 때 보다 필요하게 될 것이며, 어떻게 하면 부하곡선의 피크치를 억제할 것인지 생각하게 된다. 이러한 것을 해결하기 위해 전력회사들은 그들의 소비자 대부분을 수요관리 프로그램에 참여시키 부하관리를 할 것이며 이를 통해 피크치 부하를 억제시켜 한계비용을 줄이려할 것이다. 소비자들을 수요관리 프로그램에 참여토록 유도하기 위하여 전력회사는 여러 가지 인센티브를 제공하게 되는데, 소비자들은 이러한 인센티브를 받아 프로그램에 참여할 것인지를 선택하게 된다. 본 논문에서는 전력회사가 수요관리 프로그램을 실행할 때 어떤 효과를 얻게 되고 참여자들이 느끼는 순이익은 어떻게 될지를 고려하게 될 것이다. 이러한 것들은 전력회사 입장에서는 수요관리 프로그램을 실행하는 것이 그들에게 이익을 가져다 줄 것인지를 말해주며 소비자들은 그들의 프로그램에 지속적으로 참여할 것인지를 선택하게 될 것이다.

• Journal of the Korean Society for Heat Treatment
• /
• v.8 no.1
• /
• pp.44-52
• /
• 1995

The specimen for laser hardening have been carried out using SM45C which is coated with black paint or graphite for better absorption. Segmented mirror was used in order to produce a square beam ($10{\times}10mm$) at the surface with a homegeneous intensity distribution across the beam. $CO_2$-Laser power was changed from 2kW to 4kW and transfer velocity was varied from 0.1m/min to 2.0m/min. The maximum hardness and case depth of SM45C steel are 790Hv and 1.5mm by laser hardening. When the surface of specimens was melted during laser hardening. the surface hardness of SM45C steel was decreased. The surface hardness of 2 layer coated specimen(black paint: $15.4{\mu}m$, graphite coating: $9.5{\mu}m$) was increased than that of 1 layer coated specimen. It is desirable to prepare 2 or more coating layer on the steel surface in order to sufficient case depth and hardness in laser hardening. The graphite coating on the specimen surface was obtained more uniform temperature distribution than black paint coating in laser hardening process.

• Korean Journal of Environment and Ecology
• /
• v.23 no.2
• /
• pp.143-150
• /
• 2009

To investigate the vegetation structure of the mountain ridges ranging of Shins un-Bong, this research set up 14 plots($400m^2$) as survey target areas. As a result of the analysis of woody plant cluster, it was classified as two groups-Quercus variabilis-Quercus serrata community and Carpinus tschonoskii community. Quercus variabilis and Quercus serrata was found as a mostly dominant woody plant species in the ridge areas of Shinsun-Bong, while Carpinus tschonoskii were mixed up partly in high altitudes. High negative correlations were shown between Quercus variabilis-Sambucus sieboldiana and relatively high positive correlation were found to exist between Styrax japonicus-Quercus serrata, Sambucus sieboldiana-Rhododendron schlippenbachii, Tilia amurensis, Styrax obassia-Cornus kousa, Rhododendron schlippenbachii-Carpinus laxiflora, Cornus kousa-Tilia amurensis. Species diversity index(H') of investigated groups were ranged from $1.237{\sim}1.497$, and it was relatively high value compared to that of the vegetation structure of other national park.

• Journal of the Korean Society for Library and Information Science
• /
• v.27
• /
• pp.99-124
• /
• 1994

This study examines the establishment of Sea-po (서포) in the opening period of Korea at the end of the 19th century. The role they played, the particular situations and their geographical characteristics are researched, The earliest sea-po was Koh-je-hong sea-po, which was established in Tae­kwang-kyo at the end of 1880s. Around 1905, a specialised book distribution system was set up with establishement of Chu-han-yung book store, Kim-sang-man book store, Jesuit book store, Tae-dong su-si, Kae-myung sea-kwan, Tong-wha seo-kwan. The owners of the seo-pos were pioneers in introducing modern culture with nationalistic consciousness, although they were primarily businessmen and their social origins varied. The primary role of seo-pos was selling a variety of books but some combined printing and publication of books as well. It seems that publication business took roots around 1908, though it is difficult to know the accurate dates of first attempts. Some sea-pas offered book rental services for poor people who could not easily afford to purchase books. A certain amount of deposit had to be paid to benefit from the services. Jesuit Bookstore in Pyungyang had a library facility with a large stock or books in the same building open to public for free. These sea-pas started mainly in Seoul and Pyungyang, which were traditional centers for economic and cultural affairs. Early introduction of foreign cultures and commercial developments in these areas contributed to the establishment of sea-pos. The sea-po which took charge of book distribution in the provinces was set up around 1906. One of the important findings of this study is that the geographical distribution of sea-po shows the following three characteristics. First is that the area such as Seoul, Taegu and Chunju were the traditional centers of publishing culture from which Pang­gak-bon(방각본) emerged. Second characteristic is Pyungyang and the surrounding Pyungbuk province, and harbors like Inchon and Pusan, which had the benefits of early spread of modem cultures. Third characteristic is Kaesung and the surrounding Hwanghae province which bridged Pyungyang and Seoul. The reception of foreign cultures stimulated the commercial spirits traditionally attributed to Kaesung to establish sea-pas most actively.

• Journal of Korean Society for Geospatial Information Science
• /
• v.16 no.1
• /
• pp.13-21
• /
• 2008

This study conducted water quality projection of year 2010 in Miho stream of the Geum river basin by using GIS. Pollutant load data of corresponding tributary of the Miho stream is estimated based on the pollutant load of TMDL zone to simulate water quality of the Miho stream for BOD, TN, and TP. The pollutant load of the urban area such as Bochung and Musim stream basin is relatively high and the wastewater treatment plant of Chunju city directly affects the entire water quality of the target area. As a result, simulation result reveals that water treatment facility needs more refined treatment process for efficient water quality management. Also, to meet the target water quality of the Miho stream water quality simulation estimates the additional dilution flow by increasing irrigation water supplied from the Daechung dam through the Musim stream.

• Korean journal of applied entomology
• /
• v.5_6
• /
• pp.59-63
• /
• 1968

This Paper deals With the biology and the life Cycle of Eriophyes kuko KISHIDA. 1. The host of Eriophyes kuko KISHIDA is Lycium chinense MILL (Boxthorn), Solanum nigrum LINNE(Morel) and Capacium annum LINNE(Red pepper) etc. 2. Eriophyes kuko KISHIDA is migrated and propagated by physical carriers. The direction of the wind has a great influence upon migration and dispersal. 3. The number of e99s deposited by a adult female is $28.5\pm0.449$ egg period is $7.0\pm0.447$ and larval period is $4.33\pm0.667$ days respectively. 4. The size of gall diameter on the leaf of Lycium Chinense MILL after boring in each date by Eriophyes kuke KISHIDA is as follows, 1st day after boring is $290.5\pm0.3415\mu$ End 25st day after boring is $3260.5\pm0.5157\mu$ in average. 5. Adult periods are from 25 to 30 days and the egg laying period is 6 days. 6. Eriophyes kuko KISHIDA has 6 to 7 generations in a year, and hibernate they over winter in the gall as an adult. The first adult appears in late May.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.4
• /
• pp.819-829
• /
• 2017

The aim of this study is to analyze intraday price momentum. When price trends are formed, price momentum is the phenomenon that future prices tend to follow the trend. When the market opened and closed, a U-shaped trading volume pattern in which the trading volume was concentrated was observed. In this paper, we defined price momentum as the 10 minute trend after market opening is maintained until the end of market. The strategy is to determine buying and selling in accordance with the price change in the initial 10 minutes and liquidating at closing price. In this study, the strategy was empirically analyzed by using minute data, and it showed effectiveness, indicating the presence of an intraday price momentum. A pattern in which returns are increasing at an early stage is called a J-shaped pattern. If the J-shaped pattern occurs, we have found that the price momentum phenomenon tends to be stronger than otherwise. The DTW algorithm, which is well known in the field of pattern recognition, was used for J-shaped pattern recognition and the algorithm was effective in predicting intraday price movements. This study showed that intraday price momentum exists in the KOSPI200 futures market.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.28 no.3
• /
• pp.105-115
• /
• 2000

The purpose of paper is to investigate the characteristics of regulations on landscape management of historic city of Kyongju in Korea, compared with those of Nara in japan to answer the research question that what is the regulative characteristics of landscape management of historic city in Korea. We have analyzed the three laws of the two country - Urban Planning Law, Cultural Assets Protection law, and Building Law. This research has been done in terms of regulative systems of the two country and articles, ordinances, and bylaws on landscape managements of historic city Major components of urban historic landscape management are goals and devices of preservation, preserving actor, authorized actor permitting major planning change, regulatory power on landscape development, and backgrounds of enacting regulations. From this research, we have fond the fact that 1) Kyongju City has general and implicit objectives of landscape management based on conservation of natural environment while Nara City has concrete objectives of lansdscape management, 2) Kyongju City has no regulations on landscape planning while Nara City has systematic planning measures such as designation of landscape management district, planning for preservation of historic landscape, and planning for establishing urban landscape, 3) In an application of landscape management district, Kyongju City designate the district based on the general principle of urban planning district while nara City designate it in a more detailed manner such as district of preservation of historic landscape, district of landscape establishment, and district of building agreement. 4) Kyongju has no legal actor in implementation and management of historic landscape plan while Nara City has administrative organization and procedures, including citizen participation, public hearing, and voluntary participation, and 5) Kyongju City does not operate the consultation committee on landscape management just like Nara City operating. This research results will provide us the remedial insights for landscape preservation of such Korean historic city as Kongju, Puyo, and Chunju. Since our research is focused on the limited area of preserving landscape in historic cities in korea and Japan we need to study sociocultural issues on preserving urban historic landscape more in depth in the future.