• Title/Summary/Keyword: Use efficiency

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Effect of Long-Term Annual Dressing of Organic Matter on Physico-Chemical Properties and Nitrogen Uptake in the Paddy Soil of Fluvio-Marine Deposit (하해혼성 평야지 논토양에서 유기물 장기 연용이 토양의 이화학적 특성 변화 및 질소 흡수에 미치는 영향)

  • Yang, Chang-Hyu;Jeong, Ji-Ho;Kim, Taek-Kyum;Kim, Sun;Baek, Nam-Hyun;Choi, Weon-Young;Kim, Young-Doo;Jung, Won-Kyo;Kim, Si-Ju
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.981-986
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    • 2010
  • This study was carried out to investigate the effects of fertilizer and organic resource annual dressing for 30 years of Jeonbug series (silt loam) on soil properties and rice N uptake in paddy field soil. In the study field, treatments including control (NPK), NPK+rice straw, NPK+rice straw compost and nitrogen fertilization levels at 0, 100, 150, 200, 250 kg ha1 have been imposed for 30 years. Soil hardness and bulk density decreased from 15.7 mm and 1.381 Mg m3 in the control to 12.5 mm and 1.244 Mg m3 in NPK+rice straw compost treatment, respectively, indicating improvement of soil physical conditions such as porosity. Co-application of straw compost with NPK also result in a better chemical properties than NPK alone as it increased available phosphate (from 96 to 133 mg kg1), available silicate (from 81 to 116 mg kg1), and cation exchange capacity (from 9.8 to 11.4 cmolckg1). Soil organic matter concentration of top soil (0 to 7.5 cm in depth) was higher in NPK+rice straw and NPK+rice straw compost than in control. Fertilizer N uptake amount was much higher in NPK+rice straw (nitrogen fertilization level; 250 kg ha1) and NPK+rice straw compost (nitrogen fertilization levels; 200, 250 kg ha1) plots compared to the control (nitrogen fertilization level; 100 kg ha1) plot. Nitrogen use efficiency was showed significantly high in the NPK+rice straw compost (nitrogen fertilization levels; 100, 150 kg ha1) plot compared to the control (nitrogen fertilization level; 100 kg ha1) plot. Therefore, it was suggested that application of organic inputs is helpful in improving soil fertility and physical conditions and thus in N uptake.

Comparative Environmental Effects of Digestates Application to the Rice Paddy Soil in Bioenergy Village : Field trial (저탄소녹색마을내 혐기소화액 순환이용에 대한 논토양 환경 영향 비교)

  • Hong, Seung-Gil;Shin, JoungDu;Kwon, Soon-Ik;Park, Woo-Kyun;Heo, Jeong-Wook;Bang, Hea-Son;Yoon, Youngman;Kang, Kee-Kyung
    • Journal of the Korea Organic Resources Recycling Association
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    • v.19 no.1
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    • pp.123-130
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    • 2011
  • Objectives of this study were to compare the environmental effects of digestates produced in bioenergy village on the rice paddy field for recycling. Digestates were applied to the soils and the soil properties and the crop responses were analyzed according to the standard methods of soil evaluation. Plant height and the number of tiller showed similar results in both the conventional and digestate treated field, and the yield of rough rice was higher in the field treated with digestates than that with chemical fertilizer. The amounts of nitrogen absorbed in straw and grain were larger in the digestates-treated field than chemical fertilizer-treated one, and efficiency of nitrogen applied was shown to be the highest in 100% treated digestate of the pig manure. Exchangeable cation and pH increased in the soil treated with digestate after harvesting, but salt was not accumulated. With these results, it was concluded that resource recycling in green town can be facilitated through the securement of arable lands for the application of digestates and the proper use of these fertilizers. Long-term effects of digestate application on the soil environment should be sustainingly studied.

Basic Study for Selection of Factors Constituents of User Satisfaction for Micro Electric Vehicles (초소형전기차 사용자만족도 구성요인 선정을 위한 기반연구)

  • Jin, Eunju;Seo, Imki;Kim, Jongmin;Park, Jejin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.5
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    • pp.581-589
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    • 2021
  • With the recent increase in the introduction of micro-electric vehicles in Korea, interest in micro-electric vehicle user satisfaction is increasing to revitalize related markets. In this paper, a basic study was conducted on the development of public services using micro-electric vehicle based on the constituent factors of user satisfaction. The survey includes: ① 'Analytic Hierarchy Process (AHP) for selecting the priority factors of user satisfaction of micro-electric vehicles', ② 'A survey of micro-electric vehicles image' to collect data in advance for providing users' preferences and transportation services for micro-electric vehicles, ③ In order to investigate the user satisfaction level of users who actually operated micro-electric vehicles, the order of 'user satisfaction survey of micro-electric vehicle drivers' was conducted. In the Analytic Hierarchy Process (AHP) analysis, it was found that users regarded as important in the order of 'user utilization data', 'vehicle movement data', and 'charging service data'. In the micro-electric vehicle image survey, users perceived micro-electric vehicles more positively in terms of "safety", 'durability', 'Ride comfort', 'design', 'MOOE (Maintenance and other operating expense)', and 'environment-friendly' when comparing micro-electric vehicles with electric motorcycles. In the survey on the user satisfaction of micro-electric vehicle drivers, the use of micro-electric vehicle did not directly affect work performance efficiency, and there was an experience of being disadvantaged on the road due to the size of the micro-electric vehicle, and driving in a cluster of micro-electric vehicle for outdoor advertisements. The city's public relations effect was great, but it was concerned about safety. In the future, based on the results of this study, we plan to build a user satisfaction structural equation model, preemptively discover feedback R&D for micro-electric vehicle utilization services in the public field, and actively seek to discover new public mobility support services.

A Study on Determinants of Korean SMEs' Foreign Direct Investment in Gaeseong Industrial Complex & Vietnam (중소기업의 개성공단 및 베트남 직접투자 결정요인 연구)

  • Cho, Heonsoo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.4
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    • pp.167-178
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    • 2021
  • The purpose of this study is to analyze the direct investment decision factors in the Kaesong Industrial Complex and Vietnam, and to contribute to the creation of domestic jobs and the revitalization of the inter-Korean economy. According to the analysis, most of the Kaesong Industrial Complex and Vietnamese investment companies are entering the complex for the purpose of utilizing cheap labor, cheap factory locations, sales/development of local markets, and bypass export production bases in third countries. This can be divided into production-efficient investors using differences in production price such as labor costs and market-oriented investors to sell and expand the local market, which seems to be consistent with global direct investment patterns such as Nike, Apple, and Amazon. However, even if the North Korea-U.S. denuclearization talks ease or lift sanctions, Vietnamese investors' willingness to invest in the North Korea has been most burdened by the possibility of closing special economic zones due to political risks. Last but not least, it is important to note that those willing to invest in North Korea are mostly smaller enterprises in textiles, sewing, footwear and leather industries-those that benefit from low-cost labor. Since their size is small, they need policy support in financing, especially in the early stages of their business. Even after they grow past the early stages, those without collateral would still need state guarantee letters to get financing. Thus, it is worth considering to use the Inter-Korean Cooperation Fund to compensate commercial banks for bad loan loss or for low-interest loans for smaller SMEs. The interviews with SMEs found that red-tape is one of the biggest difficulties they face. Thus, it is recommended that a one-stop service agency should be established to cover all processes and issues related to inter-Korean economic cooperation to eliminate redundancy and expediate government support for SMEs.

A study on the characteristics of Goryeo dynasty cargo tag mokkans In comparison with mokkans of the Song and Yuan dynasty (고려시대 화물표 목간의 특징에 대한 고찰 - 중국 송·원대(宋·元代) 목간과의 비교를 중심으로 -)

  • LEE, Yeonjae
    • Korean Journal of Heritage: History & Science
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    • v.54 no.4
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    • pp.60-77
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    • 2021
  • From 2007 to 2011, four Goryeo Dynasty vessels, namely the Taean treasure ship, Taean Mado Shipwreck No.1, No.2, No.3 were discovered in Taean area, Chungcheongnam-do province. From the shipwrecks, 175 pieces of mokkan (wooden tablet) were excavated. These mokkans are the only case of Goryeo Dynasty and represent the unique usage of mokkan as cargo tags, after the paper replaced the wooden tablets as writing materials. The Taean mokkans provide details, such as the year, recipient, port of origin, types of the cargo, quantity and unit, the name of the responsible person for shipment. Thus, they enable us to speculate about the characteristics of the cargo. Furthermore, through studying the writing style, form, material and manufacturing method, researchers can extract which form and characteristics were favored at that time. The Taean mokkans have no preset style for writing. Therefore, they can be written selectively and freely. And since the mokkan were attached to cargos, mokkans with furrows on upper side were favored, and efficiency and simplification of the manufacturing process were priorities in making mokkans. The Taean mokkans can be compared to those from the Shinan ship and the Quanzhou ship because those are of the same era and use. On the writing styles and information, Chinese mokkans are focused on the cargo owners, while The Taean mokkan includes more detailed information, such as the recipients. In forms, Chinese mokkans have maximum thickness of 1.0 centimeter and have pointed edges in lower parts, while mokkans from Taean do not have fixed thickness or edges. Furthermore, Chinese mokkans and Korean mokkans have different styles from manufacturing methods and material selections. These differences between Chinese and Goryeo mokkan are related to the differences between littoral-transport Goryeo ships and ocean-transport Chinese ships, such as shipping distances, types of cargo, shipping systems, packing methods, and transport operators. At the moment, because there are only small amount of data and materials of Chinese mokkan, comparative studies regarding Goryeo and Chinese mokkan can only be fragmentary. However, this article can be a base from which to expand the scope of Goryeo mokkan studies.

Growth and Quality of the Strawberry (Fragaria annanassa Dutch. cvs. 'Sulhyang') as affected by Complex Nutrient Solution Supplying Control System using Integrated Solar Irradiance and Substrate Moisture Contents in Hydroponics (수경재배 시 적산 일사량과 배지 수분 함량 복합 급액 제어에 의한 '설향' 딸기(Fragaria annanassa Dutch. cvs. 'Sulhyang')의 생육 및 품질)

  • Choi, Su Hyun;Kim, So Hui;Lee Choi, Gyeong;Jeong, Ho Jeong;Lim, Mi Young;Kim, Dae Young;Lee, Seon Yi
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.367-376
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    • 2021
  • Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm-2 treatment had the highest fresh weight, and the 100 J·cm-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

Comparative Analysis of the Effects of Heat Island Reduction Techniques in Urban Heatwave Areas Using Drones (드론을 활용한 도시폭염지역의 열섬 저감기법 효과 비교 분석)

  • Cho, Young-Il;Yoon, Donghyeon;Shin, Jiyoung;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.37 no.6_3
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    • pp.1985-1999
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    • 2021
  • The purpose of this study is to apply urban heat island reduction techniques(green roof, cool roof, and cool pavements using heat insulation paint or blocks) recommended by the Environmental Protection Agency (EPA) to our study area and determine their actual effects through a comparative analysis between land cover objects. To this end, the area of Mugye-ri, Jangyu-myeon, Gimhae, Gyeongsangnam-do was selected as a study area, and measurements were taken using a drone DJI Matrice 300 RTK, which was equipped with a thermal infrared sensor FLIR Vue Pro R and a visible spectrum sensor H20T 1/2.3" CMOS, 12 MP. A total of nine heat maps, land cover objects (711) as a control group, and heat island reduction technique-applied land covering objects (180) were extracted every 1 hour and 30 minutes from 7:15 am to 7:15 pm on July 27. After calculating the effect values for each of the 180 objects extracted, the effects of each technique were integrated. Through the analysis based on daytime hours, the effect of reducing heat islands was found to be 4.71℃ for cool roof; 3.40℃ for green roof; and 0.43℃ and -0.85℃ for cool pavements using heat insulation paint and blocks, respectively. Comparing the effect by time period, it was found that the heat island reduction effect of the techniques was highest at 13:00, which is near the culmination hour, on the imaging date. Between 13:00 and 14:30, the efficiency of temperature reduction changed, with -8.19℃ for cool roof, -5.56℃ for green roof, and -1.78℃ and -1.57℃ for cool pavements using heat insulation paint and blocks, respectively. This study was a case study that verified the effects of urban heat island reduction techniques through the use of high-resolution images taken with drones. In the future, it is considered that it will be possible to present case studies that directly utilize micro-satellites with high-precision spatial resolution.

A High-Eating Quality Rice Variety 'Cheonghaejinmi' Adaptable to Low Nitrogen Fertilizer Application (질소 소비료 적성 고양식미 벼 신품종 '청해진미')

  • Oh, Myung-Kyu;Kim, Yeon-Gyu;Kim, Myeong-Ki;Cho, Young-Chan;Hwang, Hung-Goo;Hong, Ha-Cheol;Choi, Im-Soo;Kim, Jeong-Ju;Lee, Jeom-Ho;Baek, Man-Kee;Choi, Yong-Hwan;Jeong, Jong-Min;Yang, Chang-In;Oh, Sea-Kwan;Choi, In-Bea;Won, Yong-Jae;Chun, A-Reum
    • Korean Journal of Breeding Science
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    • v.42 no.3
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    • pp.307-312
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    • 2010
  • 'Cheonghaejinmi' is a new japonica rice variety developed from three-way cross between Samjiyeon/SR14694-57-4-2-1-3-2-2//Iri402 by the rice breeding team of National Institute of Crop Science, RDA. Heading date of this variety is August 18, 4 days later than that of 'Sobibyeo' in middle plain areas. It has culm length of 78 cm, 125 spikelets per panicle, 92.5% of ripened grain rate, and 23.9 g of 1000-brown rice weight. It showed 12 days of heading delay, and 63% spikelet fertility in cold-water irrigation stress. 'Cheonghaejinmi' is susceptible to blast disease, bacterial blight, virus diseases and plant hoppers. The nitrogen use efficiency of this variety is higher than that of Sobibyeo in low nitrogen application level. Milled rice of 'Cheonghaejinmi' exhibits translucent, clear non-glutinous endosperm and medium short grain. It has 5.9% protein content, 20.3% amylose content, and 0.28 palatability index of cooked rice compared to -0.11 of Hwaseongbyeo. The milled rice yield of 'Cheonghaejinmi' was about 5.31 MT/ha at low nitrogen application level of ordinary season culture. This variety had 98.8% whole grain in milled rice and 76% milling recovery of whole grain. 'Cheonghaejinmi' would be adaptable to middle plain areas and middle-western coastal areas in Korea.

Assessment of an Optimum Biochar Application Rate for Tomato(Solanum lycopersicum L.) Cultivation (토마토 재배를 위한 바이오차 최적시용 비율 평가)

  • Park, Do-Gyun;Hong, Seung-Gil;Jang, Eunsuk;Shin, Joung-Du
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.1
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    • pp.39-48
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    • 2019
  • Objective of this study was to evaluate an optimum biochar application rate and estimate the carbon sequestration based on the soil chemical properties and growth responses for biochar application during tomatoes cultivation. The treatments consisted of control as recommended application rates of fertilizers, 0.01%, 0.03%, 0.05%, and 0.07% of biochar application(w/w, biochar:soil). For effects of soil chemical properties, the NO3Ncontents in the soil were peaked at 9 days after transplanting. But there was not significant difference(p>0.05) among the treatments during cultivation periods. However, NH4N contents in the biochar treatment were lower than the control until 14 days of transplanting. P2O5 contents in the biochar treatments were lower than that of the control until 19 days after transplanting except 0.01% of biochar application plot. K2O contents in soils treated with 0.01% and 0.03% of biochar were higher until 6 days after transplanting than that in the control. For N use efficiency of biochar application, it was observed that the 0.05% biochar application plot was highest among the treatments. The highest carbon sequestration was estimated at 2.83mgkg1 for 0.03% of biochar application. However, it is considered that the optimum biochar application rate was 0.05% for tomato cultivation, considering the growth characteristics and yield components.

Evaluation of the influence of a visual design of an examination guide on patient comprehension and testing accuracy (검사 안내문의 시각적 디자인화가 환자의 검사 이해도 및 정확성에 미치는 영향 평가)

  • Kang, Young-Eun;Jung, Woo-Young;Hong, Bo-Ruem
    • The Korean Journal of Nuclear Medicine Technology
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    • v.23 no.1
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    • pp.29-34
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    • 2019
  • Purpose An examination guide is a useful medium to provide the patient with an overview, pre- and post-test preparation, and precautions of nuclear testing. The design and arrangement of existing written texts and announcements were evaluated to elucidate the comprehension of patients undergoing testing. Materials and Methods Informational material describing bone scanning and 201thallium myocardium perfusion single-photon emission computed tomography (SPECT), as a secondary examination, which accounts for the largest portion of gamma imaging at Asan Hospital (Seoul, South Korea), was selected as an improvement target in consultation with a national innovation center. Existing informational material was dispensed to patients scheduled for bone scans from November 2016 to February 2017 and the revised material was issued from March 2017 to May 2017. A survey was conducted of 200 patients who underwent 201thallium myocardium perfusion SPECT before and after the revisions (n = 100 each time period) to assess the patients' understanding of the informational material. Results When comparing the use of the conventional vs. revised material, the number of patients who received treatment before bone scanning had decreased from 130 to 60, while the number of those who required additional imaging decreased from 53 to 14. Prior to the revision, 43% of patients underwent testing before preparation and 18% underwent additional testing. The decreased need for additional image acquisition after revision of the informational material resulted in a decrease in acquisition time of about 2 min, from 16.5 to 14.2 min. In the case of 201thallium myocardium perfusion SPECT, patient comprehension of all five items surveyed had increased, while the number of patients who had repeatedly asked about various facets of the procedure pre- and post-testing had decreased from 36% to 16% and 31% to 14%, respectively. Conclusion Lower patient comprehension is accompanied by a decrease in image quality due to non-compliance during pre-testing and may lead to repetitive questions from the patient, which may also negatively affect the fatigue and work efficiency of the examiner. Improved readability and visibility of informational material through visualization was correlated with greater patient comprehension as well as improved image quality and acquisition time.