• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.36-43
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• 2020

BACKGROUND: Wicheon watershed has the largest irrigation area among the mid-watershed of Nakdong river. However, no investigation of irrigation water quality has been conducted on the Wicheon watershed, which evaluates the effects on the soil quality and crop cultivation. Therefore, this study aims to provide various assessments of water quality of Wicheon watershed as the scientific basic data for efficient agricultural activities. METHODS AND RESULTS: Water sampling was performed in five locations of the first tributaries of Wicheon. Wicheon watershed showed clean water quality with very low organic matters and safe water quality from metals at all points of investigation. It was estimated that the natural chemical components of Wicheon watershed were originated from water-rock interaction in Gibbs diagram. All samples were concentrated in the type of Ca-HCO₃-Cl in the Piper diagram. The quality of irrigation water was evaluated with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), and percent sodium (%Na). The values of these water quality indices were in the range of 0.37-0.67, -2.11--0.24, 41.13-84.52% and 11.28-21.84%, respectively, and were classified as good grades at all sites. CONCLUSION: The water quality of Wicheon watershed was very low in salt, indicating good irrigation water suitable for growing agricultural products. We hope that the results of this study will be used as the basic data for the cultivation of agricultural products and promotion of their excellence.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.79-86
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• 2003

This research was conducted to present reference data to be used as newly reclaimed tidal land management. We investigated vegetation succession at 4 reclaimed/reclaiming project areas and discussed relationship with soil and vegetation trhrough investigation and analysis soil chemical characteristics at 2 areas. 14 families 58 kinds were investigated. Vegetation were variou at Dea-Ho conservation polt and Seok-Mun National Industrial Area which are maintaining naturally. Vegetation were simple at Hong-Bo and Dongjin and MinKyong river areas which effected sea water. Common species that were investigated at 9 sites were Suaeda asparagoides, Aster tripolium, Phragmites australis, Suaeda maritima, Suaeda japonica, Carex scabrifolis. As soil desalinization progressing, soil classified at first saline-soidc soil, the nest saline soil and then normal soil. Chenopodiaceae revealed at about 30 dS/m of soil ECe and existed to 10 dS/m of soil ECe. At about 20 dS/m of soil ECe. Aster tripolium, Calamagrostis epigeios, and Sonchus brachyotus revealed and then non-halophytes and common plants at inland revealed at low soil ECe of about 10 dS/m. However it was not to progress vegetation sucdession and soil desalinization at the same time, owing to input of seeds or plants ect from out-ecosystem. So for promotion of vegetation at newly reclaimed tidal land, we proposed that it was very effective to plant artificially halophytes or suitable species through soil test.

• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.368-387
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• 2007

In order to explain geomorphological characteristics of the Korean Peninsula, it is necessary to understand the spatial distribution of tectonic movements and its causes. Even though geomorphological elements which might have been formed by tectonic movements(e.g. tilted overall landform, erosion surface, river terrace, marine terraces, etc.) have long been considered as main geomorphological research topics in Korea, the knowledge on the spatial distribution of tectonic movement is still limited. This research aims to identify the spatial distributions of tectonic movement via sequential analyses of Digital Elevation Model(DEM). This paper first developed a set of terrain analysis techniques derived from theoretical interrelationships between tectonic uplifts and landsurface denudation processes. The terrain analyses used in this research assume that elevations along major drainage basin divides might preserve original landsurfaces(psuedo-landsuface) that were formed by tectonic movement with relatively little influence by denudation processes. Psuedo-landsurfaces derived from a DEM show clear spatial distribution patterns with distinct directional alignments. Lines connecting psuedo-landsufaces in a certain direction are defined as psuedo-landsurface axes, which are again categorized into two groups: the first is uplift psuedo-landsurface axes that indicate the axis of landmass uplift; and the second is denudational psuedo-landsurface axes that cross step-shaped pusedo-landsurfaces formed via surface denudation. In total, 13 axes of pusedo-landsurface are identified in the Korean Peninsula, which show distinct direction, length, and relative uplift rate. Judging from the distribution of psudo-landsurfaces and their axes, it is concluded that the Korean Peninsula ran be divided into four tectonic regions, which are named as the Northern Tectonic Region, Center Tectonic Region, Southern Tectonic Region, and East Sea Tectonic Region, respectively. The Northern Tectonic Region had experienced a regional uplift centered at the Kaema plateau, and the rate of uplift gradually decreased toward southern, western and eastern directions. The Center Tectonic Region shows an arch-shaped uplift. Its uplift rate is the highest along the East Sea and the rate decreases towards the Yellow sea. The Southern Tectonic Region shows an asymmetric uplift centered a line connecting Dukyu and Jiri Mountains in the middle of the region. The eastern side of the Southern Regions shows higher uplift rate than that of the western side. The East Sea Tectonic Region includes south-eastern coastal area of the peninsula and Gilju-Myeongchun Jigudae, which shows relatively recent tectonic movements in Korea. Since this research visualizes the spatial heterogeneity of long-term tenonic movement in the Korean peninsula, this would provide valuable basic information on long-term and regional differences of geomorphological evolutionary processes and regional geomorphological differences of the Korean Peninsula.

• Journal of the Korean Dietetic Association
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• v.8 no.3
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• pp.280-288
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• 2002

The purpose of this study was to investigate the operational characteristics of the contract-managed highschool foodservice and to analyze the factors to effect the menu price. The data was collected from 249 highschools in Seoul. The results are as follows; Those surveyed highschools were established as 1 national, 74 public, and 174 private institution. Highschools were classified as 176 academic, 66 vocational, and 7 specific purposed institution. Students were organized as 70 boys', 23 girls', and 41 coeducational highschools. Most highschool started contract-managed highschool foodservice from 1999 and the period of foodservice contract was most 3 years and the operation styles in food distribution were 96 classrooms, 105 dining halls and 17 classrooms combined dining halls. The scale of contract foodservice management companies was 63.1% small and medium and 36.9% large enterprises. The surveyed highschools had the average meal price 2,141 won per meal and they had 1,518 pupils on the register. The participating rate to the foodservice was 68.5%. The facilities investment cost of the contract foodservice management company was 179,204,230 won for private institutions and was 138,119,010 won for national&public institutions. The period of the contract was 3.22 years in private institutions, which was significantly higher than national&public institutions which showed 2.85 years. The commissary foodservice schools had higher facilities investment cost than conventional foodservice schools. Classrooms foodservice had higher participating foodservice rate than Dining halls. The investment cost for facilities showed high in order of girls', boys', and coeducational high schools, and the number on the register and the number participating in the foodservice showed high in order of boys', girls', and coeducational high schools. The number on the register showed the highest in academic and vocational schools, specific purposed institutions in sequence, and the number participating in the foodservice showed high in order of academic schools, specific purposed institutions and vocational. However, the participating foodservice rate showed high in specific purposed institution, academic and vocational schools in order, and the meal price, the investment cost for facilities showed high in specific purposed institution, academic and vocational schools in sequence. Regionally, the district south of Han river had the average meal price 2,266.13 won, which showed higher in the eastern part which had 2,033.33 won. The western part had the average investment cost for facilities of 233,331,060 won, and the central district 126,137,140 won. The number on the register showed 1845.68 in the eastern part and 1308.00 in Dong-Jak area, that had clear differences among areas. When the period of the contract went longer, the investment cost for facilities had a tendency to increase. The significant differences were existed among meal price, the investment cost for facilities, the number on the register, the number participating in the foodservice, and the participating foodservice rate. The investment cost for facilities had increased according to the number participating in the foodservice and the participating foodservice rate. And the large enterprises showed higher participating foodservice rate than the small and medium enterprises.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.124-141
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• 2019

This research explored the relationship between the water quality issue of Wolji Pond (Anapji Pond) with the maintenance of the channel flow circulation system. The water supply and drainage system closely related to the circulation system of pond has been reviewed, rather than the existing water supply and drainage system that has been analyzed in previous studies. As a result of reviewing the water supply system, it has been learned that the water supply system on the southeastern shore of Wolji Pond, being the current water supply hole, has been connected to the east side garden facility (landscaping stone, curved waterway, storage facility of water) between the north and south fence and the waterway. This separate facility group seems to have been a subject of the investigation of the eastern side of Wolji Pond, with the landscaping stones having been identified in the 1920's survey drawings. The water supply facility on the southeastern shore, being the suspected water supply hole, seems to have some connection with the granite waterway remaining on the building site of Imhaejeon (臨海殿) on the southern side of Wolji Pond. It is inferred that it provides clean water, seeing that the slope towards the southwestern shore of Wolji Pond becomes lower, the landscaping stones have been placed in the filter area, and it is present in the 1920's survey drawings and the water supply hole survey drawing of 1975. The water drainage facility on the northern shore is composed of five stages. The functions of the wooden waterway and the rectangular stone water catchment facility seem not to be only for the water drainage of Wolji Pond. In light of the points that there are wood plugs in the wooden waterway and that there is a water catchment facility in the final stage, it is judged that the water of Balcheon Stream (撥川) may be charged in reverse according to this setup. Namely, the water could enter and exit in either direction in the water drainage facility on the northern shore It also seems that the supply to the wooden waterway could be opened and shut through the water catchment facility of rectangular stone group as well. The water drainage facility on the western shore is very similar to the water drainage facility on the northern shore, so it is difficult to avoid the belief that it existed during the Silla Dynasty, or it has been produced by imitating the water drainage facility on the northern shore at some future point in time. It seems to have functioned as the water drainage facility for the supply of agricultural water during the Joseon Dynasty. The water supply and drainage facilities in Wolji Pond have been understood as a systematized distribution network that has been intertwined organically with the facility of Donggung Palace, which was the center of the Silla capital. Water has been supplied to each facility group, including Wolji Pond, through this structure; it includes the drainage system connecting to the Namcheon River (南川) through the Balcheon Stream, which was an important canal of the capital center.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.12
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• pp.715-732
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• 2009

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.119-129
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• 2009

Building construction trends have been changed dramatically in terms of size and mass. With the need to maximize land usage, there has been an increase in the construction of high-rise buildings. This affects not only the entire construction duration and cost, but also subsequent construction activities, such as work to increase underground facilities and in reclamation land area construction. These types of site conditions require soft ground reinforcement and the proper uplift water pressure treatment. In general, two kinds of methods have been used for uplift water pressure treatment systems. However, there have been some problems arising as the result of a lack of research and analysis on underground construction techniques, and a reliance on experiments over actual survey and analysis of site conditions. This paper focused on the problems of conventional selection procedure, by analyzing drawings and proposing a kind of modeling for a reasonable procedure. The results were applied to OO project as a sample construction case to be verified in this research. The initial plan in the case project was the Rock Anchor System. However, as there were terrible miscalculations of basic site conditions that had an extraordinary influence on the underground water level, such as the site's proximity to the Han-river, it was necessary to change the plan to include apermanent drainage system. This achieved a direct construction cost reduction \ 406,702,000 and a maximum sayings of 4% of operational cost, based on the 50-year building Life Cycle Cost.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.122-130
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• 2010

The Study takes the rivers in Zhouzhuang - traditional Chinese Kangnam watery landscape as the object. The purpose of this study is to grasp the relationships between visual characteristics and the preference. The following is the research process: Firstly, the theoretical study of Zhouzhuang, the traditional Kangnam region in China, is conducted, the watery landscape is taken pictures, and 22 photos are selected. Secondly, in order to grasp the visual preference and landscape characteristics of the watery landscape in Zhouzhuang, 22 pictures and 25 pairs of adjectives are adopted for the questionnaire survey. Thirdly, in order to have a better understanding on the physical properties and effects of physical quantity on the preference, the occupation ratios of buildings and sculptures, natural elements, footpaths, bank revetments and other landscape elements are calculated, and the mean analysis, dispersion analysis and regression analysis are conducted. In order to grasp the landscape characteristics and preference factors, 25 pairs of adjectives are used to conduct the factor analysis. In order to grasp the effects of characteristics of visual factors on the preference, the dispersion analysis and regression analysis are carried out. The results are as follows: From the results of the landscape preference analysis, in the No.22 photo with the top preference, 11 pairs of adjectives, namely, "harmonious-disharmonious", "beautiful-ugly", "rural-urban", "soft-rough", "stable-instable", "romantic-realistic", "cheerful-gloomy", "brilliant-simple", "natural-artificial", "familiar-strange", and "clean-dirty" have positive effects on watery landscape. It can be viewed as the relatively important factor in the visual preference. In terms of the results of visual physical quantity analysis of traditional Chinese Kangnam watery landscape, the landscape with high occupation ratio of buildings and sculptures has positive effects on visual preference. The results of analysis of visual physical quantity and preference show that the preference degree increases as the occupation ratio of footpath area increases. The analysis results of visual characteristics of traditional Chinese Kangnam watery landscape identify four factors, namely psychological factor, cultural factor, condition factor and physical factor. It can be concluded from the results of analysis of the relationships between visual preference and visual characteristics that the return coefficient B of the psychological factor is +0.936. It can significantly affect the watery landscape, so it can be identified as the most important factor among the visual preference factors of Chinese Kangnam watery landscape.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.113-124
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• 2012

The Confucian culture of the Chosun Dynasty has a great effect on the construction of ByeolSeo gardens. Among them, especially the gardens built in Gyeongsang Province areas, where a great number of Confucian scholars were produced in the beautiful natural environment, have maintained various heritage of Confucian culture established by the scholars. Along with the Nakdong River, we can find so many cultural assets of buildings such as head houses, ByeolSeo gardens, including the literary remains such as administrative certificates, poetry and prose, and records of pavilions, which show the trace of the scholars who followed the instructions of the doctrines of Chu-tzu. The Geumseonjeog located in Punggi County, Gyeongsangbuk Province, which was the ByeolSeo gardens possessed by Geumgye Whang Jun-ryang(1517-1563), who was the governor of the area and one of the representative students of Toigye Lee Whang. The building is located nearby the Geumseon Valley with beautiful natural scenery under Sobaek Mountain. Especially the pine forest around the valley boasts a unique natural setting. This study is aimed to analyze the value of natural scenic spot of the Geumseonjeong through the surveys on surroundings, topography, vegetation and water system. including the value of humanistic elements focused on the writings such as 'Geumgyejip' written by Whang Jun-ryang and Lee Whang, another 'Geumgyejip' written by Ryu un-ryong, and 'Geumgyejeongsajungsugi' written by Hong Gyeong-ryeom. And also, the scenic spot value of the signboards such as the 'Geumgyejeongsajungsugi' written by Ryu un-ryong, 'Geumgyejeong' by Lee Han-il, 'Geumgyejeong' written by Jo Un-hyeong and 'Geumgyejeongsa, written by Lee Jung-gi, was analyzed. And the historical and cultural value was analyzed through the semantic interpretation of the series of poetry and pose and the old map established in 1872. In respect of the scenery, the surroundings of the Geumseon Valley boast the outstanding settings as the clean mountain stream in front of the Geumseonjeong makes a beautiful harmony with the pine forest. The pine forest surrounding the Geumseon Valley has played a secret role in the history of the village. Considering the fact that the pine forest was expressed in the map of Punggi County produced in 1872, it may be assumed that the forest was regarded to have historical and scenic value in those times. Considering the fact that the words like 'Beautiful' and 'Scenic spot' were used in the writings like 'Geumgyejip' and there were meeting places around the valley, we can recognize the value of the place as a scenic spot. The beautiful natural scenery surrounding the ByeolSeo gardens, and the increase in humanistic value of the poetry and prose, including the administrative certificates, has recently brought about the cases in which some scenic spots of the ByeolSeo gardens were designated as cultural assets. According to the value as a scenic spot and semantic interpretation of the Geumseonjeong, the pavilion appeared to have a great scenic spot value as a ByeolSeo gardens, so that this study was designed to prepare criteria with which the pavilion may be designated as a scenic spot of ByeolSeo gardens.