• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.353-360
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• 2017

In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.

• Parasites, Hosts and Diseases
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• v.28 no.3
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• pp.183-194
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• 1990

In an attempt to develop prophylactic and therapeutic measures of the intestinal giant-cystic disease caused by Thelohanellus kitauei in the Israel carp, Cyprinus carpio nodus, pathological observations were conducted upon the carps which were hatched in May 1988 and raised in a net cage fish farm at the Soyang lake, managed by Horim Fisheries for the period of 21 months with 1~2 months interval. After a gross inspection of the carps, necropsy was carried out periodically in order to clarify the pathological changes in various internal organs and muscular tissues. Also. the prevalence of the disease was checked during the period from 1988 to 1990. Gross inspections revealed that the infected carps showed some degree of fading in body and gill color, back-emaciation symptoms, reddish anus accompanying erosion and relaxation and pot-belly, as well as discharge of yellowish white mucoid material from the anus. However, most carps died eventually of intestinal obstruction. Other significant necropsy fadings included cyst formation of various size in the intestinal mucosa, ascites, anemic condition through internal organs and muscular tissues, hyperemia and dilation of intestines with decreased tension, thinness and fragility, and full contents of semi-fluid or yellowish white mucoid material in the intestinal canals. Based on the morphological characteristics of the spores found in the cysts, parasitic location in the intestines, macro- and microscopic findings of the lesions, the parasites were identised as Thelohanellus kitauei Egusa os Nakajima, 1981. Although monthly changes of water temperature were distinct, the extrusion rates of the polar filaments of the spores stayed constant throughout the year with an exception of a lower rate in July, The lesions initiated from mucosa and submucosa in early July became large swellings and then complete mature (orms following the peracute course. From late August the upper cysts were gradually opened and most of the spores were dispersed from anus into the surrounding water through December but only a few lasted until next April. The cysts were completely recovered until next September. Comparing the incidence and prevalence of the disease by year tremendous infection and death rates were checked in the first prevalent year, 1988, but the rates were significantly decreased in the second year, and showed an almost normal status in the third year, 1990. As the above summarized results showed, the disease entity might come to an end in three years after the first prevalent year, however, the spores must be strictly prevented because they could be infective in the water for one year.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.603-609
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• 1992

To investigate the effect of polyethylene film packaging and $CO_2$ treatment on tomatoes during storage, the gas composition in film, weight loss, the changes of color, hardness and several components were measured. The concentrations of $CO_2$ and $O_2$ in film were changed rapidly in early stage, but it kept a constant level after 7 days of storage. In 0.06 mm polyethylene film, $CO_2$ and $O_2$ concentration was kept a level of $4{\sim}6%$ respectively. The increase in $C_2H_2$ concentration was delayed in thick and $CO_2$ treated film. The rate of weight loss was 4% in non-packed tomatoes, but it recorded about 1% in 0.06 mm polyethylene film. Titratable acidity, pH and soluble solids were changed slightly, but the obvious differents were not observed according to film thickness and $CO_2$ treatment. The value of tomatoes was increased but L and b values were not changed greatly during storage. These color changes were restricted by 0.06 mm film and $CO_2$ treatment. The firmness and content of ascorbic acid were reduced during storage but it restrained by $CO_2$ treatment and film packaging. Sugar of tomatoes were composed of glucose, fructose and a very small amount of sucrose, and they were changed little during storage.

• Korean Journal of Agricultural Science
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• v.23 no.1
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• pp.159-176
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• 1996

This study is aimed at reviewing the methods of joint cost allocation and allocating the joint cost of estuary dam with specially repect to Kumgang Large-scale Agricultural Comprehensive Development Project. Apart from the water resource development project propelled by Water Resource Development Corporation in connection with Law of Multipurpose Dam Development, the Largescale Comprehensive Agricultural Development Projects couldn't ins-titutionally be carried out cost allocation of common facilities, even though it were concerned with irrigation, municipal and industrical water supply, flood control, sightseeing and industrial zone development components. To decrease farmer's burden of the project costs and, operation and maintenance costs, the joint costs of common facilities like estuary dam included in agricultural development projects have to be allocated by suitable method as alternative cost-remaining benefit method and the analytical activity should be supported by revising the concerned laws as Rural Development and Promotion and, Rural Rearrangement conpatible with the law for multipurpose dam development. Kumgang Agricultural Comprehensive Development Project was selected as a case study for the estimation of socio-economic benefits by project components and joint cost allocation of the estuary dam. The main results of the study are as follows; Joint cost allocation and unit charges by components 1. The project area will be 25,554ha with total project cost of 624,860 million won including the estuary dam cost of 120,843 million won. The project costs were ex-pressed by 1994 constant price. 2. Total quantity of water was estimated 365 million tons which were consisted of 245 million tons for irrigation, 73 million tons for municipal water and 47 million tons for industrial water. 3. The rates of joint cost allocation were amounted to 34.2% for agriculture, 2.5% for sightseeing, 45.7% for transportation, 11.8% for M & I water supply and 5.8% for flood control respectively. 4. The unit financial charges by project components were estimated at 7.88 won per ton for irrigation, 16.11won for M & I water, 1,686won per vehicle one pass, 977won per Pyeong according to the capital recovery method. The financial charges using straitline method for depreciation were estimated at 7.88won per ton for irrigation, 9.12won per ton for M & I water, 624won per vehicle one pass for transportation and 331won per Pyeong for sightseeing area. 5. The unit economic charges by project components were estimated at 21.1 won per ton for irrigation, 15.2won for M & I water, 977won per vehicle one pass, 977won per Pyeong according to the capital recovery method. The economic charges using straitline method for depreciation were estimated at 11.72won per ton for irrigation, 8.61won per ton for M & I water, 331won per vehicle one pass for transportation. Policy recommendation 1. The unit operation and maintenance costs for irrigation water in the paddy field couldn't be imposed as the water resource cost untreated. 2. The dam costs including investment cost and O & M cost, as a joint cost, had to be allocated by each benefited components as transportation, M & I water supply, flood control, irrigation and drainage, and sightseeing. But the agricultural comprehensive project have been dealt as an irrigation project without any appraisal socio-economic benefits and any allocating the joint cost of estuary dam. 3. All the associated project benefits and costs must be evaluated based on accounting principle and rent recovery rate of the project costs and O & M costs should be regulated by the laws concerned. 4. The rural development and promotion law and rural rearrangement law have to be revised comprising joint cost allocation considering free rider problems. 5. The government subsidy for the agricultural base development project has to be covered all the project costs. In case of common facilities representing joint cost allocation problems, all the allocated casts for other purposes like transportation and M & I water supply etc. should be recovered for formation in investment fund for agricultural base development and to procure O & M costs for irrigation facilities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.270-278
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• 2009

To understand the seed characteristics among cultivated types of Perilla crop and their weedy types in Korea and Japan, we studied the variation of 69 accessions by examining weight of 100 seeds, hardness of seed, germination percent and germination energy. The survey of the weight of 100 seeds and hardness of seed, clarified as follows; cultivated type of var. frutescens showed a range of 0.177 to 0.402 g with weight of 100 seeds, and most accessions of cultivated type of var. frutescens have soft seeds, except for several accessions, which have hard seeds, whereas weedy type of var. frutescens showed a range of 0.045 to 0.172 g with weight of 100 seeds, and has only hard seeds. While cultivated type of var. crispa showed a range of 0.054 to 0.101 g with weight of 100 seeds, and has only hard seeds. The weedy type of var. crispa showed a range of 0.059 to 0.135 g with weight of 100 seeds, and has only hard seeds. According to the result of germination tests, although the most accessions of cultivated and weedy types of var. frutescens and cultivated and weedy types of var. crispa showed below 50% germination rate at the first germination test, but some accessions of cultivated type of var. frutescens showed above 50% germination. While, in the second or third germination tests, most accessions of cultivated types of Perilla crop and their weedy types showed above 50% germination rates, except for several accessions. As a result, in this study, the average of germination percent and germination energy among accessions of cultivated types of Perilla crop and their weedy types showed respectively the highest value at the third germination test, but showed the lowest value at the first germination test. In addition, the germination percent and germination energy showed much higher in the room temperature condition than in $28^{\circ}C$ constant-temperature condition. Although our results may be required much clearly survey in the further study, this current results will be help for our understanding the variation of seed characteristics among cultivated types of Perilla crop and their weedy types in Korea and Japan.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.252-252
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• 2017

Nowadays water shortage is becoming one of the biggest problems in the Korea. Many different methods are developed for conservation of water. Soil water management has become the most indispensable factor for augmenting the crop productivity especially on soybean (Glycine max L.) because of their high susceptibility to both water stress and water logging at various growth stages. The farmers have been using irrigation techniques through manual control which farmers irrigate lands at regular intervals. Automatic irrigation systems are convenient, especially for those who need to travel. If automatic irrigation systems are installed and programmed properly, they can even save you money and help in water conservation. Automatic irrigation systems can be programmed to provide automatic irrigation to the plants which helps in saving money and water and to discharge more precise amounts of water in a targeted area, which promotes water conservation. The objective of this study was to determine the possible effect of automatic irrigation systems based on soil moisture on soybean growth. This experiment was conducted on an upland field with sandy loam soils in Department of Southern Area Crop, NICS, RDA. The study had three different irrigation methods; sprinkle irrigation (SI), surface drip irrigation (SDI) and fountain irrigation (FI). SI was installed at spacing of $7{\times}7m$ and $1.8m^3/hr$ as square for per irrigation plot, a lateral pipe of SDI was laid down to 1.2 m row spacing with $2.3L\;h^{-1}$ discharge rate, the distance between laterals was 20 cm spacing between drippers and FI was laid down in 3m interval as square for per irrigation plot. Soybean (Daewon) cultivar was sown in the June $20^{th}$, 2016, planted in 2 rows of apart in 1.2 m wide rows and distance between hills was 20 cm. All agronomic practices were done as the recommended cultivation. This automatic irrigation system had valves to turn irrigation on/off easily by automated controller, solenoids and moisture sensor which were set the reference level as available soil moisture levels of 30% at 10cm depth. The efficiency of applied irrigation was obtained by dividing the total water stored in the effective root zone to the applied irrigation water. Results showed that seasonal applied irrigation water amounts were $60.4ton\;10a^{-1}$ (SI), $47.3ton\;10a^{-1}$ (SDI) and $92.6 ton\;10a^{-1}$ (FI), respectively. The most significant advantage of SDI system was that water was supplied near the root zone of plants drip by drip. This system saved a large quantity of water by 27.5% and 95.6% compared to SI, FI system. The average soybean yield was significantly affected by different irrigation methods. The soybean yield by different irrigation methods were $309.7kg\;10a^{-1}$ from SDI $282.2kg\;10a^{-1}$ from SI, $289.4kg\;10a^{-1}$ from FI, and $206.3kg\;10a^{-1}$ from control, respectively. SDI resulted in increase of soybean yield by 50.1%, 7.0% 9.8% compared to non-irrigation (control), FI and SI, respectively. Therefore, the automatic irrigation system supplied water only when the soil moisture in the soil went below the reference. Due to the direct transfer of water to the roots water conservation took place and also helped to maintain the moisture to soil ratio at the root zone constant. Thus the system is efficient and compatible to changing environment. The automatic irrigation system provides with several benefits and can operate with less manpower. In conclusion, improving automatic irrigation system can contribute greatly to reducing production costs of crops and making the industry more competitive and sustainable.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.93-100
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• 2004

The content of nutrients such as organic carbon, nitrogen, phosphorus and potassium accumulated on soil layers in Quercus mongolica forest of Mt. Songnisan National Park located at central part of Korea was measured, and then the decomposition constants and decay times of the nutrients were also calculated by the negative coefficience model(O1son,1963). The quantities of organic carton of L-layer, F-layer, H-layer and $A_1$-layer of the forest stand were 231.25 g $m^{-2}$, 291.50 g $m^{-2}$,166.91 g$m^{-2}$ and 174.51 g $m^{-2}$, respectively. The content of organic carbon and nitrogen contained in L-layer and F-layer showed large quantity than those of other layers. The large amount of phosphorus and potassium was observed at the B-layer and $A_1$-layer. On the other hand, the decomposition constants(k) of soil organic matter were as follows : organic carbon (k = 0.3657), nitrogen (k = 0.3319), phosphorus (k = 0.2050), and potassium (k = 0.0934) and the decay times needed to 99% decomposition of nutrients in soil organic matter were as follows: that is, organic carton, nitrogen, phosphorus and potassium was 13.94 years, 15.18 years, 24.79 years, and 55.11 years, respectively. By the application of Turbo Pascal Program on the inflowed and outflowed nutrients to the forest stand,87.67% (714.84 g $m^{-2}$) of organic carbon inflowed was decomposed and 81.62% (1,594.62 g $m^{-2}$) of organic carbon accumulated was decomposed. And 84.98% of nitrogen inflowed was decomposed and 70.26% of nitrogen accumulated was also decayed.50.00% of phosphorus input and 40.31% of potassium input were decomposed, and 38.40% of phosphoyus and 33.03% of potassium accumulated were also decayed, respectively. Therefore, it is suggested that Quercus mongolica forest surveyed in the present study is maintaining in steady state because input and output amounts of nutrients is shown a similar pattern.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.189-198
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• 2000

The stochiometric mixture of evaporating materials for the $CuGaSe_2$single crystal thin films were prepared from horizontal furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal $CuGaSe_2$, it was found tetragonal structure whose lattice constant $a_0}$ and $c_0$ were 5.615 $\AA$ and 11.025 $\AA$, respectively. To obtains the single crystal thin films, $CuGaSe_2$mixed crystal was deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $610^{\circ}C$ and $450^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about 0.5$\mu\textrm{m}$/h. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction (DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by pizoelectric scattering in the temperature range 30 K to 150 K and by polar optical scattering in the temperature range 150 K to 293 K. The optical energy gaps were found to be 1.68 eV for CuGaSe$_2$sing1e crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation then the constants in the Varshni equation are given by $\alpha$ = $9.615{\times}10^{-4}$eV/K, and $\beta$ = 335 K. From the photocurrent spectra by illumination of polarized light of the $CuGaSe_2$single crystal thin films. We have found that values of spin orbit coupling $\Delta$So and crystal field splitting $\Delta$Cr was 0.0900 eV and 0.2498 eV, respectively. From the PL spectra at 20 K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be 0.0626 eV and the dissipation energy of the acceptor-bound exciton and donor-bound exciton to be 0.0352 eV, 0.0932 eV, respectively.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.97-107
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• 2011

Nowadays there are a lot of issues about copyright infringement in the Internet world because the digital content on the network can be copied and delivered easily. Indeed the copied version has same quality with the original one. So, copyright owners and content provider want a powerful solution to protect their content. The popular one of the solutions was DRM (digital rights management) that is based on encryption technology and rights control. However, DRM-free service was launched after Steve Jobs who is CEO of Apple proposed a new music service paradigm without DRM, and the DRM is disappeared at the online music market. Even though the online music service decided to not equip the DRM solution, copyright owners and content providers are still searching a solution to protect their content. A solution to replace the DRM technology is digital audio watermarking technology which can embed copyright information into the music. In this paper, the author proposed a new audio watermarking algorithm with two approaches. First, the watermark information is generated by two dimensional barcode which has error correction code. So, the information can be recovered by itself if the errors fall into the range of the error tolerance. The other one is to use chirp sequence of CDMA (code division multiple access). These make the algorithm robust to the several malicious attacks. There are many 2D barcodes. Especially, QR code which is one of the matrix barcodes can express the information and the expression is freer than that of the other matrix barcodes. QR code has the square patterns with double at the three corners and these indicate the boundary of the symbol. This feature of the QR code is proper to express the watermark information. That is, because the QR code is 2D barcodes, nonlinear code and matrix code, it can be modulated to the spread spectrum and can be used for the watermarking algorithm. The proposed algorithm assigns the different spread spectrum sequences to the individual users respectively. In the case that the assigned code sequences are orthogonal, we can identify the watermark information of the individual user from an audio content. The algorithm used the Walsh code as an orthogonal code. The watermark information is rearranged to the 1D sequence from 2D barcode and modulated by the Walsh code. The modulated watermark information is embedded into the DCT (discrete cosine transform) domain of the original audio content. For the performance evaluation, I used 3 audio samples, "Amazing Grace", "Oh! Carol" and "Take me home country roads", The attacks for the robustness test were MP3 compression, echo attack, and sub woofer boost. The MP3 compression was performed by a tool of Cool Edit Pro 2.0. The specification of MP3 was CBR(Constant Bit Rate) 128kbps, 44,100Hz, and stereo. The echo attack had the echo with initial volume 70%, decay 75%, and delay 100msec. The sub woofer boost attack was a modification attack of low frequency part in the Fourier coefficients. The test results showed the proposed algorithm is robust to the attacks. In the MP3 attack, the strength of the watermark information is not affected, and then the watermark can be detected from all of the sample audios. In the sub woofer boost attack, the watermark was detected when the strength is 0.3. Also, in the case of echo attack, the watermark can be identified if the strength is greater and equal than 0.5.

• Progress in Medical Physics
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• v.16 no.1
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• pp.10-15
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• 2005

IAEA's guidance levels have been provided for western people to the end. Guidance levels lower than the IAEA'S will be necessary in view of Korean people's proportions. Therefore, we need to develope the standard doses for Korean people. And we conducted a nationwide survey of patient dose from x-ray examinations in Korea. In this study, the 278 institutions were selected from Members Book of Korean Hospital Association. The valid response rate was approximately 57.9%. Doses were calculated from the questionnaires by NDD method. We obtained the results were as follows; 1) General radiographic equipments were distributed for 42.0%, fluoroscopic equipments 29.4%, dental equipments 13.2%, CT units 8.1 % and mamographic units 7.2%. 2) According to classification by rectification, three-phase equipments were 29.9%, inverter-type generators 29.5%, single-phase equipments 25.5%, constant voltage units 9.0% and unknown units 6.0%. 3) According to classification by receptor system, film-screen types were 46.8%, CR types 26.8%, DR types 17.7% and unknown types 8.9%. 4) The number of examinations were chest 49.2%, spine 16.8% and abdomen 12.7%. 5) Patient doses were head AP 3.44 mGy, abdomen AP 4.25 mGy and chest PA 0.39 mGy.