• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2089-2092
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• 2002

The PID controller have the simple structure and show the comparatively good control performance. Crystal Grower(FF-CZ150) melt polycrystalline silicon at the temperature of about 1450$^{\circ}C$, then grow it into a single crystalline ingot. The automatic diameter control system of the Crystal Grower has a good performance with only PD control. But it contain the integrator in the plant which has a long time delay. In this paper, we show the secondary approximate model and applies time delay controller which has good performance for the plant with long time delay. It will be able to improve the response characteristic against a standard input and a load disturbance.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2799-2802
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• 2003

The automatic diameter control system of the Crystal Grower has a good performance with only PD control. But it contained the integrator the plant which has a long time delay. In this paper. we show the secondary approximate model and applies time delay controller which is good performance for in the long time delay plant. It will be able to improve the response characteristic against a standard input and a load disturbance.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.2
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• pp.279-286
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• 2010

Livestock production in Vietnam is, as in most Asian countries, increasing rapidly and changing into specialized highly intensified operations. The volume of animal excreta generated exceeds the capacity of the operation land base and cannot be utilized efficiently. As a consequence, there is a loss of plant nutrients from livestock farms that causes environmental pollution. This study carried out a feed and excretion experiment measuring fecal characteristic, daily fecal production, daily nitrogen and phosphorous excretion from grower-finisher pigs fed prevalent rations in Vietnam. Furthermore, equations for assessing the excretion were tested, which can be used in farm models for optimal recycling of manure while focusing on reducing pollution. The results indicated that fecal production and nutrient excretion were affected by the different rations tested. This study showed that five selected equations for predicting excretion from grower-finisher pigs in Danish conditions can also be used with precision in Vietnamese pig farming systems. The equations have been proven valid and can, therefore, be used as a much needed tool for assessing fecal production and nitrogen in excreta on pig farms. The study also showed that about 12% of nitrogen excreted was emitted during housing. Waste water contains more than half of the nitrogen excreted, mainly in ammonium form which has a high potential for gaseous emission.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.214-227
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• 2018

An object oriented crop model was developed to perform crop growth simulation taking into account complex interaction between biotic and abiotic factors in an agricultural ecosystem. A set of classes including Atmosphere class, Plant class, Soil class, and Grower class were designed to represent weather, crop, soil, and crop management, respectively. Objects, which are instance of class, were linked to construct an integrated system for crop growth simulation. In a case study, yield of corn and soybean, which was obtained at an experiment farm in Rural Development Administration from 1984 to 1986, were compared with yield simulated using the integrated system. The integrated system had relatively low error rate of corn yield, e.g., <4%, under sole and intercropping conditions. In contrast, the system had a relatively large underestimation error for above ground biomass except for grain compared with those observed for corn and soybean. For example, estimates of biomass of corn leaf and stem was 31% lower than those of observed values. Although the integrated system consisted of simple models, the system was capable of simulating crop yield under an intercropping condition. This result suggested that an existing process-based model would be used to have more realistic simulation of crop growth once it is reengineered to be compatible to the integration system, which merits further studies for crop model improvement and implementation in object oriented paradigm.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10b
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• pp.3-16
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• 2000

Protection agriculture is the essential choice for human to increase the efficiency of limited crop production area under harsh and changeable weather boundary conditions, extend growing season, maximize the crop yields, and then increase the sustainable income of the grower. The investment costs far greenhouses as well as labor and energy costs are much higher than for conventional plant production systems, so these can only be balanced by better crop yields, higher labor productivity, and higher energy efficiency. (omitted)

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.93-96
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• 2001

Estimation of leaf wetness duration (LWD) facilitates assessment of the likelihood of outbreaks of many crop diseases. Models that estimate LWD may be more convenient and grower-friendly than measuring it with wetness sensors. Empirical models utilizing statistical procedures such as CART (Classification and Regression Tree; Gleason et al., 1994) have estimated LWD with accuracy comparable to that of electronic sensors.(omitted)

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.212-226
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• 2002

North American ginseng production may have been maximized in the traditional growing areas in the last decade and further increases may be in woods grown root, for niche markets. The marketplace demands high quality roots. Most problems leading to low quality roots start with the grower and can be avoided. These include poor site selection, inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices. Selection of low lying sites increased the plant damage from frost in Ontario in May 2002. Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plant. Opportunities exist for shortening the stratification period of North American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued. Disease is the major problem in ginseng cutivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control although challenges will arise such as with Quintozene and its replacement with Quadris for control of diseases caused by Rhizoctonia. Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.

• Journal of Ginseng Research
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• v.7 no.2
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• pp.172-192
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• 1983

Light environment and growth of Panax ginseng In habitat and cultivation under natural shade were renewed. Grower's experiences on ginseng stand In relation to light environment were assessed. Change of shading method and grower's concepts on light requirement of ginseng plant in Korea, Manchuria and Japan was counted. Growth of wild ginseng was better under rich light. Optimum crown density index appeared to be 0.7 In natural habitat and 0.4 to 0.7 for the cultivation in forest. Change of light Intensity in forest was greatest in May and reached near to constant value (from 40% to 3% for broad leaf deciduous forest and loom 4% to 2% for pine forest). Insufficient light condition induced long and thin stem, poor flowering and seed bearing, and sequent dormancy. Relation between light and ginseng strand was not clear but light Interception with cool weather was effective. Topography and orientation of bed have been deeply considered for light environment. Panel or bark of won were used for shading in deep forest manly In Manchuria while reed blind and straw thatch were used in Korea. Kinds and number of shades material and seasonal or daily schedule have been simplified probably by labor pressure due to eulargement of plantation. Post height has been greater while width of roof, bed and ditch has changed lisle. Scientific survey in the past omitted important light control methods (complete light hardening etc) which has been practiced in specific areas. The concept and technique of light control in the past in Korea were delicate and intensive including the control of temperature and moisture. For the application of old concept in modem cultivation precise Investigation of the technique including the measurement of light, temperature and moisture is needed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.141-144
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• 2023

현재 대한민국은 고령 사회이다. 매년 노인인구의 비율을 증가하고 있으며 2025년에는 노인인구 비율이 20%가 넘으면서 초고령사회로 접어들 전망이다. 이러한 사회적 특성으로 우리는 많은 노인 문제를 겪고 있다. 그 중 대표적인 문제는 독거노인의 비율이 증가함에 따라 매년 고독사하는 독거노인이 많아지고, 지방의 농가인구 또한 점점 감소하고 있다는 점이다. 본 논문에서는 이러한 사회문제를 해결하기 위해 Flutter를 활용한 애플리케이션 개발을 통해 식물과 IOT 기술을 접목하여 이들에게 도움을 주고자 한다. 독거노인에게는 반려 식물 시스템을 제공하여 이들의 우울증을 완화하고, 지방의 농가인구에 효과적인 스마트팜 시스템을 서비스 함으로써 이러한 사회문제를 해결하는 데 도움을 주고자 한다.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.407-418
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• 2002

This study was conducted to evaluate the efficacy of wheat and wheat bran  as the source of phytase in a 5 week broiler feeding trial. One thousand day-old broiler chickens(Ross$^{(R)}$) were divided into 20 pens of 50 broilers(25 male and 25 female) each. Four pens were randomly arranged to one of the five dietary treatments: T1, control diet containing normal nonphytate P(NPP) ;  T2, T1 － 0.1% NPP; T3, T2 ＋ 600IU microbial phytase(NOVO$^{(R)}$) per kg diet; T4, T2 ＋ 600IU plant phytase from wheat and wheat bran; T5, T2 ＋ 600IU plant phytase from wheat and hydrothermally treated wheat bran. Reduction of NPP level by 0.1%(T2) reduced weight gain and feed intake but plant phytase treatments(T4 and T5) recovered the lost performance. Plant phytase treatments showed better (p<0.05) weight gain and intake than the microbial phytase treatment(T3). There was no difference between regular wheat bran treatment(T4) and hydrothermally treated wheat bran treatment(T5). Mortality was the highest by low NPP diet(T2). Availability of ether extract and crude ash of grower diet was the highest(p<0.05) in normal wheat bran diet(T4). Availability of Ca and P of grower diet was the highest(p<0.05) in T4 followed by T3 and T5. Availability of Mg, Fe and Zn was drastically improved by phytase treatments(T3, T4 and T5). Excretion of Ca, P, Mg, Fe and Zn was the lowest(p<0.05) with microbial phytase treatment(T3). Serum level of Ca and Mg was the highest(p<0.05) with the low NPP treatment(T2). Tibial ash content of T2 and T3 was lower(p<0.05) than that of T1, T4 and T5. However, tibial Ca content was higher(p<0.05) in T1 and T2 than other treatments. Tibial P and Mg contents were the highest(p<0.05) in T1. It was concluded that plant phytase from wheat bran can be effectively used to improve P utilization. Hydrothermal treatment of wheat bran prior to inclusion in the diet had no beneficial effects.