• 한국농공학회논문집
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• 제53권6호
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• pp.129-136
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• 2011

To measure effects of surface cover on runoff and sediment discharge reduction using rainfall simulator, four(5 m${\times}$30 m scale) plot experiments were conducted in this study. Surface covers made with straw mat, Polyacrylamide (PAM), chaff, and sawdust were simulated 4 times under 31.1~44.4 mm/hr rainfall intensities. Compared with results from control plot, the time of runoff generation is delayed and outflow volume decreased with surface cover. Effects on runoff reduction of straw mat, PAM, sawdust and chaff ranged 4.7~81.5 % and runoff rate reduced by 6.5~76.1 % respectively, when compared with those from control plot. The percentage of decrease in sediment discharge were 99.7~99.8 % from straw mat+sawdust+PAM plots, 85.9~95.6 % from straw mat+PAM plots, and 98.5~99.4 % from straw mat+chaff+PAM plots. The runoff, sediment discharge, and SS concentration reduction efficiencies of the cover materials were outstanding when compared to control plot. It was analyzed that reduction of runoff and sediment discharge were mainly contributed by decrease in rainfall energy impact and flow velocity and increase of infiltration due to the surface cover materials. The results could be used as a base for the development of best management practices (BMPs) to reduce runoff, sediment discharge from sloping field.

• 한국환경복원기술학회지
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• 제4권1호
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• pp.1-15
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• 2001

The purpose of this study is to evaluate the creation techniques of eco-pond, one of biotopes to promote biodiversity in urban residence area. Investigation were classified out plant, mammals, amphibia, reptiles, birds, fishes and insects. The results were summarized as follows: Around the eco-pond shows simple vegetation structurs, consisted of Pinus densoflora S et Z. and Robinia pseudoacacia under competition. In case of shrub, consisted of 4 species but plant growing appearence diversely by seasons. The evaluation of vegetation of eco-pond, there are found 4 species of aquatic plants. Inside the revetment of pond, Echinochloa crus-galli, Persicaria hydropiper, Digiaria sanguinalis, Cyperus microiria and Bidens frondosa L. are mainly distributed. Near the revetment, Trifolium repens L. and Digiaria sanguinalis are prevailed. And in its background, Erigeron canadensis, Erigeron annuus and vines are begins to make their appearances. When evaluation animals in eco-pond and contrast plot, it show simple species and numbers of mammals. It seemed to be resulted from its isolation and outside intervention by users In eco-pond, Pica pica and Streptopelia orientalis are mainly found and in contrast plot of Columba livia, which are so strong adaptation to city life environment. In case of amphibia and reptiles, none is observed in contrast plot, but in ecological pond, Rana nigromaculata and Hyla japonica are constantly observed. In case of insects, more species are found in eco-pond than contrast plot. And in eco-pond, more dragonflies are visibly increased one year after its construction. In floral zone inside of pond revetment, grasshopper and Locusta migratoria are frequently observed. In case of butterflies, they are mainly found in log fence and willow(salix) around eco-pond. In case of fishes inside of eco-pond, the species and its density are remarkable increased one year after the construction. With above evaluation results, we have identify the increase effect of biodiversity after construction of the eco-pond.

• 한국의류학회지
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• 제32권9호
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• pp.1478-1486
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• 2008

The human body composed of concave and convex curvatures, and the current 3D scanning technology which involves inherent measurement errors make it difficult to extract distinct curvature plot directly. In this study, a method of extracting the clear curvature plot and its application to the cycling pants design were proposed. We have developed the ergonomic pattern from the 3D human body reflecting cycling posture. For the ergonomic design line on the 3D human body, the 3D information on the lower part of four male bodies with flexed posture was analyzed. The 3D scan data of four subjects were obtained using Cyberware. As results, the iteration of the tessellated shell was executed 100 times to obtain optimized curvature plots of the muscles on the body surface, and the boundaries of the curvature plots were applied to the design lines. Maximum(Max-pattern) and mean curvature plots(Mean-pattern) were adopted in the design line of the cycling pants, and performance of those lines was compared with that of conventional princess line(Con-pattern). The average error of total area and length in the 2D pattern developed from the 3D flexed body surface in this study were very minimal($4.58cm^2$(0.19%) and 0.15mm(0.46%)), which was within the range of tolerable limits in clothing production. The pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the cycling skin, so that the extra ease for movement and good fit was not need to be considered.

• 한국추진공학회지
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• 제23권1호
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• pp.46-51
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• 2019

Intermittent CSR 측정법을 이용하여 NBR 오링의 노화 거동과 수명 예측에 관하여 연구하였다. Intermittent CSR jig는 오링의 실제 사용 환경을 고려하여 설계 제작하였다. 오링의 노화 거동은 $40{\sim}120^{\circ}C$에서의 가속 노화 연구를 통하여 관찰하였다. 오링은 $80^{\circ}C$ 이하에서 비선형 노화 거동을 나타내었다. 오링의 수명은 고장 조건 20%에 대하여 Arrhenius plot으로부터 32.5년, WLF plot으로 부터 22.6년으로 나타났다.

• 한국농공학회논문집
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• 제57권5호
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• pp.123-128
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• 2015

This study conducted a series of field experiments using soil conditioners, Polyacrylamide(PAM) and gypsum, to evaluate their effects in reducing sediment loss and surface runoff. In addition, the correction factors (K-alpha) for the erodibility factor (K) were determined to reflect the effects of PAM and PAM+gypsum in applying the USLE equation. Experimental erosion plots individually sized $10m^2$ (5 m long, 2 m wide and 1 m deep) have different slopes (10, 20 and 30%). Erosion plots were prepared for one control (C; no PAM and gypsum) and two treatments (P; PAM 20 kg/ha, PG; PAM 20 kg/ha+gypsum 3,000 kg/ha). The amounts of soil eroded and runoff were continuously monitored from July $1^{st}$ to Oct. $31^{st}$ in 2010 and compared to each other. The amount of sediment loss from a control plot was 399.2 ton/ha and the relative reduction of sediment loss were 11.4% and 33.4% for PAM-treated and PAM+gypsum treated plots, respectively. This study also determined the K-alpha factors in the USLE equation to account for the erosion control effectiveness of PAM and gypsum application. The K-alpha factors were calculated as 0.92 for PAM-treated plot and 0.69 for PAM+gypsum-treated plot. The findings of this study revealed that soil conditioners (PAM and gypsum) could play a significant role in controlling soil erosion. In addition, the modified USLE equation using the K-alpha could provide valuable information to make better decision on establishment of best management practice for soil erosion control in agriculture.

• The Plant Pathology Journal
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• 제19권2호
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• pp.92-96
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• 2003

The study was conducted to determine the cultural conditions and the effect of inert fillers for melanization and sporulation abilities of sodium alginate pellets, and the weeding efficacy of the formula in the field. Melanin production of E. nematosporus was affected by striking frequency. Percentage of melanized beads was increased to 80.6% at higher rpm up to 180. The melanized pellets produced more conidia with abundant mucilage than unmelanized pellets. Shaker culture of Epicoccosorus nematosporus with sodium alginate yielded a total of 55 mg per 100 pellets. Percentage of melanized pellets was highest with 81.0% and 83.3% of melanization, when wheat bran and rice polish were amended and produced the conidia with 65.4 and 68.4 mg per 100 pellets, respectively. When 1 L of conidial suspension of 6.0$\times$$10^5$ conidia per ml was applied on 30-day-old plants in a plot, 74.5% of the plants were killed within 20 days, whereas, its melanized sodium alginate pellets killed 57.8% of the plants in the same period. The number of tuber formation of Eleocharis kuroguwai in the untreated control plots was 128.5 per plot, but those of the plots treated with conidial suspension and melanized pellets were 22.1 and 39.7, respectively, at the end of the season. Results of this study showed that melanization of mycelia-mixed sodium alginate are an important sporulation factor in E. namatosporus as a mycoherbicide.

• 한국군사과학기술학회지
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• 제25권3호
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• pp.239-250
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• 2022

In this paper, we analyze the performance of an FM radio based passive radar in the presence of deception jamming such as false-target generation. To do this, we examine the effects of applying the deception jamming signal to the passive radar through the derivation of the construction of the amplitude-range-Doppler(ARD) plot. The analysis results show that applying the deception jamming signal with the low power similar to the target echo signal generates false targets at positions set by the jamming variables compared to the real target position in the ARD plot. Also, it is possible to induce the jamming effect so that only false targets are detected by selecting appropriate jamming power. Simulations are included to verify the theoretical results and to discuss on the effectiveness of the deception jamming on the FM radio based passive radar.

• 한국환경농학회지
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• 제41권1호
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• pp.16-23
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• 2022

BACKGROUND: Rice production by the current standard cultivation method is predicted to decrease due to global warming. It seems that there has been a strong warming trend in Hwaseong-si, Gyeonggi-do. This study attempted to understand the climate change in Hwaseongsi, Gyeonggi-do and to analyze the effect of climate change on rice production. METHODS AND RESULTS: The statistical and physicochemical analyses were performed using the rice cultivar 'Chucheongbyeo' yields grown at the rice paddy field plot in the Gyeonggi-do Agricultural Research and Extension Services and the weather data measured in near the rice paddy plot. CONCLUSION(S): There was no significant difference between the average rice yields per area in 2000s (2001~2010) and 2010s (2011~2020), but the rice yield variability was greater in 2010s than in 2000s. The mean, minimum, maximum temperature, and the sunshine hours were evaluated for the correlation with the rice yield. The understanding of climate change in Hwaseong-si, Gyeonggi-do and the major weather factors affecting changes in rice yield, presented in this study, would enhance scientific understanding of regional climate change, and improve rice cultivation management.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.49-49
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• 2022

One of the major problems with sweetpotato (Ipomoea batats Lam.) is the tough thread tissue that occurs in the storage root, which has a negative impact on the sales of sweet potato because it impairs the texture during cooking and the processing quality. The fiber contents in storage roots of sweetpotato is affected by cultivation conditions and environment. To investigate the effect of fiber generation at different levels of irrigation, the sweetpoatoto "Hogammi" was transplanted in greenhouse. Sweetpotato was grown in styrofoam beds(W1605*D330*H300mm) to block moisture flowing from the outside. The irrigation was carried out as 3 levels (5,10, and 20 mm through drip irrigation facilities) at 20-day intervals. Five plants were harvested per plot at 90, 100 and 120 days after transplanting (DAT). The size of the storage root was large in the order of irrigation conditions 10mm>20mm>5mm treatment. And the longer cultivation period, the larger size of the storage root was observed. As a result of the analysis of the fiber content, it showed a tendency to decrease as the cultivation period increased (90days→120days). In addition, the fiber contents of sweetpotato harvested at 90, 100 and 120 DAT in the level of 5 mm irrigation plot were 351, 324 and 207 mg/100g, respectively, which were higher than those of other irrigation level plots. During all cultivation periods, the 10mm treatment group showed the lowest fiber content of 280, 228 and 127 mg/100g. At 20 mm irrigation level, the fiber content was less than that of 5mm irrigation level, but showed a tendency to increase compared to that of 10 mm irrigation level. These results suggested that drought stress or excessive-irrigation increases the fiber content of sweetpotato, which reduces their commercial value.

• 한국산림과학회지
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• 제50권1호
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• pp.10-15
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• 1980

우리나라에서 생산(生産)되고있는 송이(松茸)는 특유(特有)한 향기(香氣)와 맛이 있어 임산물(林山物) 생산(生産) 수출품(輸出品)으로서 각광(脚光)을 받고있는 실정이므로 필자(筆者)는 1979년(年) 9월(月)부터 1980년(年) 10월(月)까지 지리산(智異山) 천은사 송림(松林)에서 송이접종시험(松茸接種試驗)을 실시(栮施)하였던 바 다음과 같은 결과(結果)를 얻었으므로 이에 보고(報告)한다. 1. 접종시험결과(接種試驗結果) 포자살포구(胞子撒布区)는 균계(菌系)만 발생(発生)하였으며 포자액관주구(胞子液灌注区) 2개(個)의 자실체(子実体)가 균계이식구(菌系移植区)는 4개(個)의 자실체(子実体)가 발생(発生)하였다. 2, 노동력(労動力) 관계(関係)로 보아 포자액관주구(胞子液灌注区)가 해려(慀励)할 수 있는 방법(方法)으로 믿어 진다. 3. 송이발생수(松茸発生樹)의 송림성장(松林成長)은 송이비발생수(松茸非発生樹)에 비(比)하여 현저(顕著)하게 늦으므로 송이(松茸)는 소나무와 공생균(共生菌)이 아니라 기생성(寄生性) 외생균근(外生菌根)으로 생각된다. 4. 송이(松茸)의 발생(発生)은 20~60년생(年生)에 한정(限定)된 것은 특수물질(特殊物質)의 분필(分泌)와 상관관계(相関関係)가 있다고 보며 송이포자접종(松茸胞子接種)도 20~60년생(年生)에 한다고 본다.