• Journal of Practical Agriculture & Fisheries Research
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• v.5 no.1
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• pp.64-76
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• 2003

This study was conducted in order to find out the basic data and informations for the accidents for repairing of agricultural machines. This study was summarized as fellows : 1. Among the total repair work, the ratio of repair accident was 68.9% and the accident ratio with power tiller, tractor, and combine was 84.8%. The accident occurred frequently in April to May and September to October because of frequent use of machines during this months. The accidents occurred often of ten to eleven and two to three afternoon in a day. 2. The 36.3% of the accident types was farming machines and the 60.4% of the accident occurred in yard of repair shop. The 34.4% of accident was caused by people, 26.2% by machines, 24.9% by environmental factors, and 14.5% by others. 3. In accident damage, human damage was 98.4% and economic damage was 43.6%. There was only 40.2% in having agricultural machinery insurance and 22.5% of research applicant answered that they would not have insurance in the future. 4. The 58.2% of the injured parts occurred in fingers, hands, wrists, or arms and the 74.4% of the damage types were bruise, prick or abrasion. The damaged parts of machinery were belt of power transmission device, chains, sharpened knives, narrow mechanism or cultivating knives for rotary. 5. The average days of medical treatment for casualty was 15.5 days and the average expense of medical treatment per person was 189,200 won. The days of temporary rest and the economic damage per person due to accident were 12.8 days and 469,300 won.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.400-405
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• 2023

Currently, inverted pendulums are being studied in many fields, including posture control of missiles, rockets, etc, and bipedal robots. In this study, the vertical posture control of the pendulum was studied by constructing a rotary inverted pendulum using a 256-pulse rotary encoder and a DC motor. In the case of nonlinear systems, complex algorithms and controllers are required, but a control method using the classic and relatively simple PID(Proportional Integral Derivation) algorithm was applied to the rotating inverted pendulum system, and a simple but desired method was studied. The rotating inverted pendulum system used in this study is a nonlinear and unstable system, and a PID controller using Microchip's dsPIC30F4013 embedded processor was designed and implemented in linear modeling. Usually, PID controllers are designed by combining one or two or more types, and have the advantage of having a simple structure compared to excellent control performance and that control gain adjustment is relatively easy compared to other controllers. In this study, the physical structure of the system was analyzed using mathematical methods and control for vertical balance of a rotating inverted pendulum was realized through modeling. In addition, the feasibility of controlling with a PID controller using a rotating inverted pendulum was verified through simulation and experiment.

• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.483-488
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• 2007

Current feeder system (CFS) for Korea superconducting tokamak advanced research(KSTAR) project plays a role to interconnect magnet power supply (MPS) and superconducting (SC) magnets through the normal bus-bar at the room temperature(300 K) environment and the SC bus-line at the low temperature (4.5 K) environment. It is divided by two systems, i.e., toroidal field system which operates at 35 kA DC currents and poloidal field system wherein 20$\sim$26 kA pulsed currents are applied during 350 s transient time. Aside from the vacuum system of main cryostat, an independent vacuum system was constructed for the CFS in which a roughing system is consisted by a rotary and a mechanical booster pump and a high vacuum system is developed by four cryo-pumps with one dry pump as a backing pump. A self interlock and its control system, and a supervisory interlock and its control system are also established for the operational reliability as well. The entire CFS was completely tested including the reliability of local/supervisory control/interlock, helium gas leakage, vacuum pressure, and so on.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.1-10
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• 2018

The objective of this study was to identify the effects of farming practices on the Misgurnus anguillicaudatus population, including their habitat characteristics, length frequency and the length-weight relationships of M. anguillicaudatus population; this study investigated the differences of the population living in environment-friendly (EFP) and conventional paddy fields (CP). As the result of age distribution by length frequency of M. anguillicaudatus, the EFP showed various age distributions which were not present in the CP. In particular, the age $0^+$ (28-51 mm) of individuals in the CP were significantly lower than those in the EFP. In May, the number of individuals was similar in CP and EFP, which led to the assumption that the M. anguillicaudatus population living in a shallow depth was killed by rotary and tillage works. The regression coefficient (b) in relation to the length-weight of M. anguillicaudatus population was 3.0, which appeared relatively stable as a habitat condition in the CP and EFP, except in June. The condition factor for M. anguillicaudatus population in the CP and the EFP showed a relatively stable monthly population, except in June which was likely to be influenced by the stress to lay their eggs or chemicals such as the use of pesticides. This change of habitat characteristics and length-weight relationship on M. anguillicaudatus population in rice paddy fields was influenced by farming practices as well as the time of year.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.11-22
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• 2017

A plaza represents the identity of a city, and that reveals a plaza's importance. Gwanghwamun Plaza and Seoul Plaza are two representative plazas where the citizens can freely express their opinions. Many major plazas in the center of Seoul were built under the Japanese occupation. Among these, the plaza of Joseon Bank has different characteristics than Gwanghwamun Plaza and Seoul Plaza. Even though this plaza was built in the center of the commercial, administrational, and cultural district during the Japanese colonial period, the research on this plaza has been limited. This study was conducted to verify the features of this plaza by analyzing its construction and transformation during the Japanese colonial period. The study's results outline how the plaza was constructed by the Japanese administration. The intention of the government is shown by the fact that it purchased land parcels and held a design competition. In the 1910s, the government purchased seven parcels of land during the expansion of roads as the place for the plaza. During the late 1930s, the government accepted a traffic circle to regulate the traffic and eliminate the conflict between crossing movements. In 1939, a fountain was built in the plaza's center, and its design was selected through a design competition. It was planned as a square, but gradually turned into a rotary. Furthermore, the plaza was a landmark and symbol of the power and modernity of Japan. As the main modal point of public transportation, the plaza became surrounded with largescale Western-style buildings, commercial advertising, and neon signs. The plaza became a place where people could experience the modern city. These spectacular displays showed that Japanese imperialism was perceived as a strange and peculiar landscape to the majority of Korean citizens. This study investigates the history and characteristics of the plaza, focusing on its beginning as well as the transformation of its form. As to the limitations of the study, it does not consider political and economic contexts within the transformation of Seoul and in relation to this plaza. Instead, that research remains for a future study.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2008.12a
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• pp.87-102
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• 2008

시설재배 토양에 녹비작물 재배와 고추재배, 휴경을 반복하면서, 외부 유기자재 투입을 최소화 하고 2년 동안 토양에 물리, 화학성에 변화를 추적하여 궁극적으로 녹비작물을 이용한 유기고추 시설 무경운 재배기술을 개발 하고자 시험을 수행한 결과 1. 고추 시설재배지 녹비작물 재배가 녹비 수량 및 토양 이화학성에 미치는 영향 시설재배지의 겨울 녹비작물을 1월 30일 파종하여 4월 5일에 조사한 결과 수량은 호밀과 보리녹비가 $518{\sim}677kg/10a$로 완두콩과 헤어리베치 $287{\sim}354kg/10a$에 비하여 건물수량이 현저하게 많았다. 녹비작물의 식물체내 총질소 함량이 완두콩과 헤어리베치, 보리가 호밀에 비하여 많았으며, 보리가 타 작물에 비하여 $P_2O_5$, $K_2O$ 함량이 높았고, 두과작물인 완두콩과 헤어리베치가 화본 과인 호밀과 보리녹비에 비하여 CaO과 MgO 함량이 많았다. 녹비작물의 토양중 무기성분 고정량이 화본과인 호밀과 보리녹비의 총질소량은 10a당 $17{\sim}18kg$, $P_2O_5$, 4.7kg, $K_2O$ $31{\sim}33kg$ 수준으로, 두과 녹비작물인 완두콩과 헤어리베치에 비하여 총질소, $P_2O_5$, 양이온인 $K_2O$ 높았으나, CaO과 MgO 고정량은 큰 차가 없었다. 2. 녹비작물 재배 후작 유기재배 고추의 생육 및 수량 겨울 재배 녹비작물을 트렉터로 로터리 작업하여 토양에 환원한 후 홍고추를 2007년 4월 27일 정식하여 조사한 결과 생육에 유의적인 차이를 보이지 않았으나, 고추 수량은 호밀녹비 재배지가 헤어리베치 재배지에 비하여 증수되는 경향을 보였다. 3. 시설재배지 2차 녹비작물 재배 시 녹비수량 및 토양 이화학성 2007년 12월 18일 2차 녹비작물을 파종 재배하여 생육량을 조사한 결과 건물 수량은 10a당 호밀은 720kg, 보리는 528kg, 헤어리베치는 230kg, 완두콩과 잡초는 217kg 수준이었다. 녹비작물 생체중의 일일 증가량은 호밀과 보리는 100kg/10a/day, 헤어리베치는 10a당 65kg 정도가 하루에 증가되었다. 녹비작물의 총질소 고정량은 화본인 보리와 호밀 녹비작물이 두과작물보다 건물수량이 많아서 2배정도 많았고, 인산은 $2.7{\sim}3.7$배, 가리의 고정량은 $2.2{\sim}2.6$배 정도 많았다. 4. 녹비작물 재배 후작 무경운 고추 유기재배의 생육 및 수량 2차 녹비작물 재배 토양에 무경운으로 풋고추를 2008년 4월 1일 정식하여 재배한 결과 녹비작물 종류에 따른 고추의 생육차는 인정되지 않았으나, 고추 수량은 무처리와 보리예취 이용 처리 및 녹비 생산량이 적은 완두콩 재배지에서 많았다. 5. 녹비작물과 고추 유기재배에 따른 시설토양 이화학성의 경시적 변화 비닐온실내의 토양에 무기화학성의 경시적 변화를 추적하여 본 결과 토양 pH는 녹비작물 재배 시 증가되는 경향을 보였으나, 고추재배 후에는 다시 토양 pH가 감소되었다. 토양에 EC는 녹비작물 재배 후 감소되었으나, 고추재배 후에는 다시 토양 EC농도가 증가되었다. 1차 녹비작물 재배 후에는 토양에 증가되었으나, 고추 재배 후에는 유기물함량이 감소되는 경향을 보였다. 토양에 총질소 함량은 녹비작물 2회 재배와 첫 번째 고추재배에서 감소되는 경향을 보였으나 두 번째 고추재배에서 급격한 증가를 보였다. 인산에 함량은 녹비작물재배와 고추 재배 시 미미하지만 공히 감소되는 경향을 보였다. 토양의 양이온 치환용량과 양이온인 토양 K, Ca, Mg함량은 녹비작물과 고추재배 시 감소되는 경향을 보였고, 고추재배에서는 같은 경향을 보였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.8-13
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• 2010

Seedling establishment, overwintering ability and dry matter production of Chinese milk vetch (Astragalus sinicus L. CMV) in natural reseeding practice were compared with the annual seedling in 2006~2007 and 2007~2008. In natural reseeding, CMV seeds were distributed up to 15 cm soil depth in autumn after rice harvest and the seeds generally emerged from soil at less than 5 cm depth while they all emerged from soil surface in the annual seeding. It took 7-8 d longer in seedling establishment of the natural reseeding practice than the annual seeding. Generally, the natural reseeding practice showed higher seedling stand than the annual seeding because of high seedling survival rate. The high seedling survival rate in natural reseeded plant was attributed to the longer root length than that of the annual-seeded plant. In annual seeding, most of the seeds emerged from the soil surface and the root can not easily penetrate the soil while, in natural reseeding technology, the seeds incorporated into the soil during land preparation emerged from the soil at 0 to 5 cm depths, thereby having longer root length. The long root length contributed to greater ability to survive even under low temperature and low soil moisture conditions during winter. The dry matter production in the natural reseeding practice was also higher than the annual seeding when the temperature is low and soil moisture is not sufficient. This result indicates that natural reseeding technology is more stable and beneficial in seedling establishment and dry matter production as compared with the annual seeding especially under unfavorable environmental condition for CMV growth. This practice could be encouraged in CMV-rice cropping system in the southern parts of Korea.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.120-126
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• 2010

As the importance of an historical area is getting increased in these days, the reconstruction of an bell chamber in Namhansansung has significant historial, educational and cultural meaning. The purpose of this study, as a study on an bell chamber in Namhansansung, is to assume an original location of the bell chamber and identify the size and shape of the original bell chamber through literature study, site inspection, and analysis on old maps. In addition, this study could provide useful information when new bell chamber is constructed. According to the literature study, site inspections(5 times) and analysis on old maps, the original bell chamber is assumed to locate near current Oroji tea house at the rotary, where was in the area of Hanggung. With regard to the traffic system, it is assume that there was an old road along with the current local road No.342 connecting the South Gate with North Gate and a Y or T shape intersection connecting the site of old bell chamber with the north. In addition, there was a government office street from the old bell chamber to Hanggung. The shape of old bell chamber is assumed to have Paljak or Woojingak roof. Samo roof was not found in all the five maps. Regarding the direction of bell chamber, three maps indicate that it faces the East and two maps show that it faces the South. Therefore, it is assumed that the length and width of the roof have similar size. However, a new bell chamber should face the East, which is the same direction with Hanggung. As there is a record which states that a bell in the Cheonheoungsa, Seonggeosan, Cheonan was used as a Namhansansung's bell when the Cheonheoungsa was closed, this study suggests that new Namansansung's bell should be built, considering histroical value and artistry of Cheonheoungsa's bell. This study is a basic research for the reconstruction of Namhansansung in 2009. However, as reconstruction of historical assets should be based on thorough historical evidences. Therefore, more detail researches by a indicator analysis are left for the topic of future studies.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.333-343
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• 2003

This experiment was carried out to improve the utilization of liquid pig manure (LPM) for rice at the two textures of valley soil in 2000 and 2001. The soil textures were coarse loamy and fine loamy in Sachon and Jisan series, respectively. Treatments consisted of no fertilized plot, chemical fertilized plot, LPM 150%, LPM 100%, LPM 100%+NK (top dressing) 30%, LPM 70%+NK 30%, LPM 50%+NK 50% plot. LPM was applied as basal fertilizer compare to nitrogen of chemical fertilized plot. Total N contents in the LPM were 6.0 and $4.5g\;kg^{-1}$ in 2000 and 2001, respectively. After the experiment, P and K contents of soils were not difference between chemical and LPM application plots. But heavy metal contents in soils were slightly higher in LPM application plots than in chemical fertilized plot. Immediately after LPM application, ammonia gas content was $18mg\;kg^{-1}$ in LPM 150% plot, but it was $3mg\;kg^{-1}$ in LPM 50% plot. Two days after LPM application, ammonia gas content was 3 times higher in coarse loamy than in fine loamy soil. After rotary tillage, ammonia gas was not detected at all LPM treatments. This result suggests that rotary tillage can reduce the nasty smell of LPM quickly. Inorganic nitrogen, $NO_3$ and $NH_4$, contents in water of paddy was higher at coarse loamy soil from rice transplanting to tillering stage. After that season, inorganic nitrogen contents of water were not different according to soil texture and treatments. Content of $NH_4-N$ in soil solution was higher at LPM plots than chemical fertilizer plot. Total nitrogen contents in rice plant after harvesting were higher at chemical fertilization plot than LPM application plot, but K contents showed an opposite tendency. Rice yield was decreased only in LPM plots at two soil textures. But yield was not significantly difference between chemical fertilizer and LPM+top dressing plots at coarse loamy soil and increased 5% at LPM 50%+NK 50% plot at fine loamy soil in 2001.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.853-858
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• 2011

The cultivation methods are important for determining crop yield of green manure. The effect of cultivation methods of green manure crops (GMC) on biomass and rice yield was investigated. This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts from Oct. 2007 to Oct. 2008 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Seven GMC (hairy vetch, barley, Chinese milk vetch, rye, crimson clover, oats, rattail fescue) were cultivated and incorporated on paddy soil by broadcasting before rice harvesting (BBRH) and partial tillage seeding (PTS). Among the three leguminous GMC, the biomass and N production were the highest at the hairy vetch of PTS. Among the four gramineae GMC, the biomass and N production tended to be higher in the rye of BBRH and barley of PTS. The C/N ratio (56.5~74.2) of rye was high compared with hairy vetch (14.1). Among the GMC, the incorporation of hairy vetch increased $NH_4$-N contents in rice paddy soil at 14 and 42 days after transplanting. These results showed that hairy vetch had no significant to rice yield compared with conventional fertilization. Therefore, hairy vetch seems to be the most efficient green manure crop as an alternatives to chemical N fertilizer in the central regions of Korea.