• International Journal of Highway Engineering
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• v.16 no.5
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• pp.73-82
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• 2014

PURPOSES : The purpose of this study is to determine the optimum addition rate of SBR latex through the evaluation of durability and strength of SBR latex applied soil pavement. Formerly used materials such as fly ash and cement in soil pavement had resulted in decreased durability due to micro crack by heat of hydration and shrinkage crack in winter. However, that agglutinated polymers help adhesion to aggregate increased comes up with preventing the crack opening when the number of capillary tubes of SBR latex get decreased in the hydration process of cement. Therefore, in this study, it is suggested that the evaluation of the field applicability of soil pavement be conducted through the performance lab test in terms of strength increment, adhesion improvement, and crack resistance based on SBR latex addition rate. METHODS : In order to evaluate the field applicability of soil pavement, SBR latex was added 0 to 3% by 1% increment, with fixed cement contents of 3% and 5%. The resistance of shear failure and crack of soil pavement were evaluated by performing the uniaxial compressive strength test and indirect tensile strength test at -20 and $20^{\circ}C$, respectively. RESULTSCONCLUSIONS : It was found out that from both tests, resistance of shear failure and crack were improved with increment of curing time, and especially more than 2% of SBR latex addition rate and 5% cement content gave better results.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.19-26
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• 2015

PURPOSES : This study intends to develop an inorganic soil pavement material using industrial by-products and to evaluate its applicability as a road pavement material. METHODS : In this study, a compressive strength experiment was conducted based on the NaOH solution molarity and water glass content to understand the strength properties of the soil pavement material according to the mixing ratio of alkali activator. In addition, the strength characteristic of the inorganic soil pavement material was analyzed based on the binder content. The performance of the soil pavement was evaluated by conducing an accelerated pavement test and a falling weight deflectometer (FWD) test. RESULTS : As a result of the soil pavement material test based on the mixture ratio of alkali activator, it was identified that the activator that mixed a 10 M NaOH solution to water glass in a 5:5 ratio is appropriate. As a result of the inorganic soil pavement materials test based on the binder content, the strength development increased sharply when the amount of added binder was over 300 kg; this level of binder content satisfied 28 days of 18 MPa of compression strength, which is the standard for existing soil pavement design. According to the measured results of the FWD test, the dynamic k-value did not show a significant difference before or after the accelerated pavement testing. Furthermore, the effective modulus decreased by approximately 50%, compared with the initial effective modulus for pedestrian pavement. CONCLUSIONS : Based on these results, inorganic soil pavement can be applied by changing the mixture proportions according to the use of the pavement, and can be utilized as road pavement from light load roads to access roads.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.239-250
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• 1993

The dynamic resilient modulus tests to determine the $M_R$ of the soils require expensive equipments and well trained personnels to obtain reliable test results. These problems inherent in the dynamic resilient modulus testing have been realized as major negative factors to hinder the $M_R$ test from being practically implemented as a routine test. In this regard. it is highly desirable to develop a simpler alternative testing method incorporating inexpensive equipments and easy-to-perform testing procedures. Developed in this study is an alternative $M_R$ test method based on statically repeated loading scheme utilizing the standard static triaxial test equipments. Applicability and limitations of the developed static $M_R$ testing method are investigated for typical subgrade soils in Korea.

• Journal of Conservation Science
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• v.6 no.2 s.8
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• pp.141-148
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• 1997

When we have entered high economic growth since 1970s, many archaeological excavations were performed all over the country. Excavated objects composed of variable materials are inevitably subjected to deformations owing to surrounding environments and storage conditions. Although the importance of conservation treatment of the objects is greatly increased, a few conservation laboratories are there comparing with excavation groups. The metallic objects excavated are very unstable and deformable state. So it is important not to allow iron objects, especially cast iron, to dry out once excavated. Because the corrosion reactions on the surface proceed rapidly, the objects may be destroyed at the moment. The conservation procedures of the excavated metallic objects are as follows: (1)It is stable on-site storage method for objects to keep vinyl film with envelop or to immerse alkaline solution to prevent the environmental changes. (2)The objects must be treated at once under suitable methods in the conservation laboratory after excavation. (3)The continued existence of objects depends on environmental factors such as relative humidities, regular inspection, light etc.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.42-47
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• 2002

가. 작업별 시험결과 1) 마늘쪽 분리·선별작업 o 마늘쪽 분리기는 통마늘을 1 또는 2∼3쪽으로 분리하여 1차 선별하고, 마늘쪽 선별기는 분리된 마늘을 3단계로 선별되며 작업성능은 시간당 60접 이상을 분리 및 선별할 수 있다. o 개발된 마늘쪽 분리기와 선별기는 소형 경량이며 취급조작이 편리한 기종하고 작업성능이 높고 손상률이 적어 '01년도에 60대가 농가 보급되었으며 '02년도에는 확대 보급될 전망이다. 2) 파종작업 o 작업성능은 경운기용 파종기 2시간/10a, 승용관리기용 직립파종기는 1시간/10a으로 능률적이었으며 작업정도와 생육상태가 양호하였다. o 지역별 파종작업 체계 -난지형 마늘 파종은 직립파종을 하며 제주, 남해 등은 마늘을 파종한 후 10-11월 줄기가 자랐을 때 무공비닐을 피복하고 줄기를 유인하며, 무안은 유공비닐을 피복하고 구멍에 마늘의 1/2 또는 2/3만 묻히도록 파종하며 별도의 줄기유인 작업은 하지 않는다. 의성지역의 한지형 마늘은 트랙터로 쇄토정지후 보행관리기로 골을 내고 인력으로 마늘을 놓으면 관리기가 다음 골을 내면서 복토하는 체계이다. 3) 마늘 수확작업 -마늘 수확기는 난지형 마늘 수확에는 효과가 적으나, 한지형과 같이 깊게 파종하여 인력으로 뽑기 어려운 재배지역에서는 필요한 기종이며, 토양수분이 많으면 굴취된 마늘과 혼이 진동판에 걸려 작업상태가 불량하므로 마늘과 흙의 이송이 원활토록 진동판 형상 및 적정 진폭 구명이 요구됨 4) 마늘줄기 절단작업 -난지형 마늘은 포장에서 건조후 단기간(1-2주)내에 줄기절단을 해야하므로 기계환가 시급하나 한지형 마늘은 아직도 대부분 줄기를 자르지 않고 묶어서 판매하고 있어 기계화의 시급도는 떨어짐 5) 마늘 선별작업 -마늘선별기는 작업성능이 높고 5등급으로 균일 선별되었으며 손상도 없었으나, 기계가 크고 무거워 이동이 곤란하고 가격이 비싸므로 선별등급을 3∼4단계로 줄이고 소형 농가보급형으로 개량제작이 요구됨. 나. 마늘재배 일관기계화에 의한 노동투하시간과 비용 -종자준비부터 통마늘선별까지의 일관기계화로 투입된 주요작업의 노력은 75∼76%가 절감되고, 재배규모 3ha기준시 비용은 44-53%절감되었음.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.331-331
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• 2020

급격한 산업화와 도시화로 인한 도시유역의 불투수면의 증가와 이에 따른 배수능력의 저하로 인해 도시 물순환의 왜곡이 발생하였다. 따라서 과거 도시 물관리 기법의 한계가 나타났으며 이를 위해 저영향개발 기법 등과 같은 도시 물관리 기법의 패러다임이 변화하였다. 본 연구에서는 저영향개발 기법에서 도시유역 내 활용이 유용한 침투형 시설 중 투수블럭에 대한 물순환 성능평가를 실외실험을 통해 분석하였다. 성능평가 실험은 부산대학교 양산캠퍼스 한국 GI&LID 센터 내 투수블록 뿐만 아니라 블록 하부 골재층까지 설치가 가능하도록 되어있어 실제 현장과 유사한 환경을 구축이 가능한 2.4×10.9×0.4 (m) 규모의 주차장형 LID 실증시험시설을 활용하였다. 인공강우 분사를 위한 실외 인공강우모사 장치 크기는 2×2(m)으로 본 시험을 위하여 5개의 인공강우모사 장치를 연결하여 활용하였으며, 본 시험장치는 강우를 공급하기 위한 수조와 펌프, 일정한 유량을 유입하기 위한 유량계, 강우를 분사하기 위한 노즐, 인공강우가 실제 강우와 같이 자유낙하 하도록 구현하기 위한 오실레이터 등으로 구성되었다. 시험대상인 틈새투수블록은 석재블록 규격 400×600×100 mm이며 재질은 받침안정층(흙), 투수블록(화강석)으로 구성되어 있다. 실험의 시나리오는 시험체에 강우강도 30mm/hr, 50mm/hr, 100mm/hr에 해당하는 양을 1시간 동안 유입하여 시험 시작 후, 강우지속시간, 표면유출지속시간, 표면유출량을 1분 단위로 측정. 시험체에 유공관이 설치된 경우에는 침투유출지속시간, 침투유출량도 함께 1분 단위로 측정하였으며 각 강우강도별로 측정하고, 1회 측정 후, 각 시험별 시험 대상체의 조건을 같게 하기 위한(하부 지반의 건조) 약 3일 이후(상황에 따라 변동 가능) 시험하였다. 본 실험의 결과, 강우강도가 30 mm/hr와 50 mm/hr인 경우에는 화강석 틈새투수블록포장에서 지표 유출이 발생하지 않았으며, 강우강도 100 mm/hr의 경우 260 L의 지표 유출이 발생하여, 불투수표면 대비 84%의 지표유출 저감률을 보여줌으로서 투수블럭에 물순환 성능에 대한 효과를 분석하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.468-468
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• 2021

도시의 개발은 불투수면의 증가, 토지이용의 변화, 용수 수요 증가를 초래하였고, 최근에는 기후변화 양극화 현상으로 도심내 물순환체계를 더욱 왜곡시키는 문제를 초래하였다. 1962년부터 서울의 도심지가 본격적으로 개발되기 시작하면서 7.8%였던 불투수율이 2010년에는 50%까지 증가하였다. 토지의 피복상태가 숲과 흙일 때는 강우의 10%는 하천으로, 토양 흡수는 50%, 증발이 40%가량 된다. 보통 토양에 흡수된 물은 토양층에서 머물렀다가 중간유출되어 하천으로 유입되거나 지하수로 전환된다. 그러나 개발로 인하여 아스팔트나 콘크리트로 포장된 경우 55%가 하천으로 유입되고 토양으로 흡수되는 양은 15% 정도로 강우가 급격하게 유출되어 빠져나가 버린다. 도시 불투수면적의 증가는 단순히 치수와 이수의 문제뿐만 아니라 도심의 하천 및 녹지공간에 조성되어 있는 생태계 유지에 필요한 최소한의 수량인 생태용수 확보마저 위협하고 있다. 도심 하천의 환경생태유량 확보는 하천의 정상적인 기능을 유지할 뿐만 아니라 하천의 자정 능력을 향상하며, 수생생물의 서식환경을 보존에 기여하므로 도심의 자연성 회복에 있어 매우 중요하다. 도시 생태환경은 녹지의 단절과 파편화로 연속성을 확보하지 못하고 있는데, 이렇게 단절되고 파편화된 생태계를 연결하여 생태축을 확보하면 도시 생태계의 건강성을 증진시킬 수 있다. 대부분의 도시에서 관리하고 있는 가로수 및 띠녹지 등 녹지공간(그린 네트워크, Green Network)을 활용하여 수원 함양이나 수질정화 기능(블루 네트워크, Blue Network)을 부여하면 녹지와 수자원을 연결한 그린-블루 네트워크를 형성하여 도시 생태용수확보에도 기여할 뿐만 아니라 나아가 도심 하천의 자연성 회복에도 기여할 것으로 기대된다. 본 연구는 도시의 가로수와 띠녹지를 활용하여 빗물저장 기능과 침투기능을 확대하기 위해 기존에 녹지 및 공원 관리 차원에서 가로수 도시계획이 수립되고 관련 사업이 진행되어 온 현행 제도상의 문제점을 검토하여 제도적 개선 방안을 제안하는 것에 목적을 둔다.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.479-487
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• 2021

This study investigated the life history of the plum sawfly Monocellicampa pruni Wei, 1998 through field observations and laboratory experiments. M. pruni is a univoltine, complete metamorphosis species with five instars at the larval stage. Adults emerge from the soil around mid-March when Japanese plum trees are in their flowering period. The adults deposit one (rarely two) egg(s) under the epidermis layer of the calyx. After hatching, the larva soon burrows into the fruitlet, consumes the endocarp and remains inside the fruit within its four-time moulting transitions before reaching full growth. At maturity (in May), the larva leaves the infested fruitlet through an exit hole and burrows into the soil at a depth of 2 - 11 cm for spinning its cocoon and hibernates until the next spring as the larval form. Under laboratory conditions (T = 20℃; RH = 40 - 60%), the male lived for a slightly shorter period than the female, 6.03 ± 0.40 and 7.55 ± 0.45 days, respectively. A female could produce 30.29 ± 4.50 eggs in her lifespan. In the field, the duration of the egg was approximately 10 - 11 days and that of the larva was approximately 31 - 34 days.

• Journal of Biosystems Engineering
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• v.6 no.1
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• pp.39-47
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• 1981

For purpose of investigation the proper paddy field condition in performance of rice transplanter according to the various elapsed times (0.5, 1, 1.5, 2 days) after puddling and plowing (12, 15, 18 cm depth), this experiment was carried out on the paddy field located in Chil Am Dong, Jin Ju City, from April to May in 1980. The results are summarized as follows; 1. The practical working power for the elapsed time 0.5 days and plowing depth 18cm was about 0.8 ps, which was the highest among the plots, so the power out-put(2.5~3.5 p.s) of these engines are considered to be enough for the transplanting under these field conditions. 2. The percentage of slip increased proportional1y to the plowing depth and decreased proportionally to the elapsed time after puddling, and the highest and lowest percentages of slip were 42.5% in elapsed time 0.5 days, plowing depth 18 cm, and 26.5% in elapsed time 2 days, plowing depth 12 cm, respectively. 3. In the plot of elapsed time 2 days and plowing depth 12 cm, the planting distance was 13.9 cm, which was closed to the proper planting distance 14 cm. 4. The percentage of missing hill was lowest(1.5%) in the plot of elapsed time 2 days and plowing depth 12 cm. 5. The planted depth in the plot of the elapsed time 2 days and plowing depth 15 cm was 2. 95 cm, which was closed to the proper planting depth 3 cm. 6. The angle of planting postures in the plot of elapsed time 2 days and plowing depth 12 cm was $89^{\circ}$, which was closed to the desirable posture angle $90^{\circ}$. 7. The deviation from the straight transplanting line was lowest in the plot of the elapsed time 2 days and plowing depth 12 cm. 8. From the results above mentioned, it is recommended that the field condition under the elapsed time 2 days and plowing depth 12 cm is the most favorable one for the working performance of rice thansplanter.

• Food Science and Preservation
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• v.16 no.4
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• pp.579-589
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• 2009

We focused on the condition of washed, fresh ginseng in the market and analyzed consumer attitudes to the product to improve the consumption of fresh ginseng. A preference for fresh ginseng was high among every age class, and was particularly notable in older individuals. Fresh ginseng was usually eaten as ginseng chicken soup, mostly in summer and winter, and as a valuable health food, rather than because of desirable qualities of taste or smell. A total of 66.5% of those surveyed reported that they had purchased fresh ginseng, mostly from big discount stores. Such stores were preferred as outlets owing to a reputation for quality and shopper convenience (the stores were located near interviewees' homes). More than 70% of purchasers emphasized that they chose to purchase in department stores and traditional markets owing to the reputation for quality of such sources. Most consumers considered quality to be a prime element in purchase decisions. A total of 32.9% of those surveyed had bought washed fresh ginseng to give as a gift to a friend. Of those surveyed, 67.1% had never bought washed fresh ginseng. The following reasons were proposed to explain the preference for purchase of ginseng with attached soil. Most consumers (40.2%) thought the soil was a reflection of quality. Those who preferred washed fresh ginseng considered that the material was hygienic and convenient to store. When questioned about their intention to buy washed fresh ginseng, 55.0% of consumers replied in the affirmative and 17.1% in the negative. When consumers were asked whether they would be willing to pay an additional charge for the washing and packing of fresh ginseng, 58.8% answered in the affirmative.