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Searching for Rotationable Vegetables for Paratylenchus projectus in Lettuce Greenhouse (해바라기침선충(Paratylenchus projectus) 피해 경감을 위한 윤작작물 탐색)

  • Kwon, Giyoon;Seo, Jongmin;Park, Sohee;Kang, Heonil;Park, Namsook;Choi, Insoo
    • Research in Plant Disease
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    • v.26 no.4
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    • pp.272-278
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    • 2020
  • The severe lettuce damage caused by Paratylenchus projectus was first reported in 2019 in Korea. To find high-value rotation crops for the control of P. projectus, nine vegetables, Brassica juncea (leaf mustard), B. rapa subsp. nipposinica (kyona), B. oleracea var. italica (broccoli), B. rapa subsp. chinensis (bok choy), B. oleracea var. viridis (kale), B. oleracea var. gongylodes (kohlrabi), Cichorium endivia (endive), C. intybus (chicory), Ipomoea aquatica (morning glory) were planted in d-10-cm clay pots in greenhouse. The growth of vegetables was compared between inoculated with 3,000 P. projectus per 100 ㎤ of soil and non-inoculated. Treatments were replicated 10 times. After 100 days, the reduction of fresh top weight was 30.4% in C. intybus, 35.1% in I. aquatica, 36.9% in B. oleracea var. acephala, 40.5% in C. endivia, 42.1% in B. rapa, 47.5% in B. rapa subsp. nipposinica, 50.4% in B. oleracea var. gonglodes, 56.3% in B. oleracea var. italica, and 66.0% in B. juncea. Nematode multiplication rates (Pf/Pi) were lower in I. aquatica (0.64) and C. endivia (1.1), but higher in B. oleracea var. gongylodes (2.54). Considering these results, I. aquatica is suitable for the rotation crop with lettuce until better rotation crops developed.

A Rational Design of Coin-type Lithium-metal Full Cell for Academic Research (차세대 리튬 금속 전지 연구 및 개발을 위한 코인형 전지의 효율적 설계)

  • Lee, Mingyu;Lee, Donghyun;Han, Jaewoong;Jeong, Jinoh;Choi, Hyunbin;Lee, Hyuntae;Lim, Minhong;Lee, Hongkyung
    • Journal of the Korean Electrochemical Society
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    • v.24 no.3
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    • pp.65-75
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    • 2021
  • Coin cell is a basic testing platform for battery research, discovering new materials and concepts, and contributing to fundamental research on next-generation batteries. Li metal batteries (LMBs) are promising since a high energy density (~500 Wh kg-1) is deliverable far beyond Li-ion. However, Li dendrite-triggered volume fluctuation and high surface cause severe deterioration of performance. Given that such drawbacks are strongly dependent on the cell parameters and structure, such as the amount of electrolyte, Li thickness, and internal pressure, reliable Li metal coin cell testing is challenging. For the LMB-specialized coin cell testing platform, this study suggests the optimal coin cell structure that secures performance and reproducibility of LMBs under stringent conditions, such as lean electrolyte, high mass loading of NMC cathode, and thinner Li use. By controlling the cathode/anode (C/A) area ratio closer to 1.0, the inactive space was minimized, mitigating the cell degradation. The quantification and imaging of inner cell pressure elucidated that the uniformity of the pressure is a crucial matter to improving performance reliability. The LMB coin cells exhibit better cycling retention and reproducibility under higher (0.6 MPa → 2.13 MPa) and uniform (standard deviation: 0.43 → 0.16) stack pressure through the changes in internal parts and introducing a flexible polymer (PDMS) film.

Industrial Policy as a Development Strategy: Cuba' s Experience and Policy Implications (개발전략으로서 산업정책: 쿠바의 경험과 정책적 시사점)

  • Cin, Beom Cheol
    • International Area Studies Review
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    • v.22 no.3
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    • pp.3-27
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    • 2018
  • This paper analyzes Cuba's market-oriented reforms to alleviate essential problems with socialist countries such as soft budget constraints and incentive problems. It also discuss about effectiveness of industrial policy as a development strategy. The soft budget constraints and incentive problems resulted in the collapse of Soviet bloc and COMECON in early 1990s. After the collapse, Cuban economy suffered a steep dive, and national income tumbling down rapidly. Cuban faced serious shortages of food, gasoline, and other basic necessities of life. To halt and partially reverse economic downturn and dire austerity in the 1990's, the Cuban government made some partial reforms to the inherited Soviet system of cental planningand faced severe shortage in food, energy, and daily necessities. In response to the economic crisis. Cuba introduced economic reforms and implemented industrial policy as a development strategy as long as Cuba maintained a strong socialist country. Cuban government established the economic free zone law and attempted to induce foreign direct investment by implementing export-led industrial policy. Fiedel Castro approved the Law No. 165 "Free Zones and Industrial Parks", in 1996. However, Cuba's ESZ strategy seems to have failed because of the U.S. sanctions, but also because of Cuba's own policies, which do not allow foreign investors to hire workers directly and impose a high implicit tax on wages. By limiting advanced techniques of personnel and organization management, indirect employment can result in lowering work efforts and productivity of workers, and aggravating production efficiency in the ESZs. Another reason to fail comes from the double wage structure due to the double monetary-exchange rate system. Most of the high non-wage costs result from the double exchange rate system. Due to Cuba's imbalanced industry and production structures, concentrated labor force, and urbanization and centralization of agriculture production, the industrial transformation development model suggested by Lewis has not been successful unlike other Asian agriculture-led development model. Cuba has to overcome many difficulties in implementing industrial policy as a development strategy.

A Study on the differentiation and development aspects of Zhu-zi xue - centering around the connection between Huang Gan and Jin-hua school in Yuan period (주자학의 사상적 분화와 전개양상에 관한 연구 - 황간(黃?)과 원대(元代) 금화학파(金華學派)의 사상적 연관성을 중심으로 -)

  • Chi, Chun-ho
    • The Journal of Korean Philosophical History
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    • no.23
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    • pp.317-347
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    • 2008
  • Huang Gan(1152 - 1220, pen-name Mian-zhai) was a famous scholar of Zhu-zi xue in the Southern Song period. Zhu-zi xue was also called Daoxue(道學), because it was based on the Cheng-Zhu xue(程朱學) and had very severe idea of Daotong(道統). Therefore, Zhu-zi xue emphasized practical movements of spreading Confucianism. The view of the Daotong(道統) developed in two aspects: protection of Confucianism and exclusion of Daoism Buddhism. Zhu Xi completed the idea of Daotong(道統), and his disciples, especially Huang Gan, continued his efforts. Zhu Xi's disciples searched the ultimate teaching of Confucianism through studying Four-books(四書). In due of their effort, Zhu-zi xue played a reading role in those academic fields. Huang Gan look upon himself as the successor to Zhu-zi xue. He expounded and missionized Zhu Xi's philosophical thought. In his later years, he accepted many students and passed the Zhu Xi's thought on to his students. He fostered "Jin-hua school(金華學派)"-He Ji(何基), the representative of this school. There is the relation of thought on the theory of knowledge and learning centering around Daotong between Huang Gan and Jin-hua school(金華學派). Especially, the most schools leading the academic society of Yuan period founded their thought on Huang Gan's. And it explained Huang Gan's historical influence and contributions to the Zhu-zi xue in the Yuan period.

A Study on the living and the experience from Captive's story of war during the Second Manchu's invasion in 1636 (병자호란기 조선 피로인(被虜人)의 호지(胡地)체험과 삶)

  • Nam, Mi-Hye
    • (The)Study of the Eastern Classic
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    • no.32
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    • pp.71-101
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    • 2008
  • This study is intended to review the war and the living of the common people of Choseon dynasty, through the true stories of captives kidnapped in the region of the Qing(胡地) during the Pyeongja horan in the 17th century. The common people, Kim seung kyung and Ahn chu won, who had been kidnapped in their young age, managed to escape from the region of the Qing to Choseon after having experienced a painful living as a captive for 27 years. Kim seung kyung and Ahn chu won had to make a choice to run away from the Qing in order to bring their war distorted life back to its original state. Kim seung kyung who had successfully escaped, could live without severe difficulties by the aid of his family living at his hometown, but Ahn chu won who had not found his own family or relatives, couldn't have got any helping hand from the people mentally or financially. So, he tried to escape again to Beijing, but discovered and captured so that a diplomatic problem was caused between the Choseon and the Qing Dynasty. Through the true story of Kim seung kyung and Ahn chu won, we can see the lives of Choseon common people who were trying to overcome the difficulties with their own iron will without being undaunted by hardships. Even though the captives had terrible experiences hating to remember, their experiences gave a chance to the Choseon people opening their eyes to the foreign cultures and the new world. At that time, the Choseon government was too weak to estimate how many captives were or what the captive's real fact was. Meanwhile the Choseon government managed to do the least duty in order to protect its people, by breaking the provisions of repatriation that the fled captives should be returned back to the Qing Dynasty. Through reviewing the captive's true story of the Choseon common people, we can ruminate the Choseon society in the 17th century which failed to establish an independent national history, and the issue of the Korean War captives in the modern history forgotten under the shade of the dustbin of history.

The Actual Use of Non-regular Workers and the Strategies of Social Partners in Sweden: with a Special Reference to Temporary Workers (스웨덴 비정규직의 사용 실태와 행위주체들의 전략: 임시직 사용 방식을 중심으로)

  • Cho, Don-Moon
    • Korean Journal of Labor Studies
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    • v.23 no.1
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    • pp.47-83
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    • 2017
  • The Swedish labor market secures flexibility in the use of labor force by means of non-regular workers such as temporary workers among others instead of regular workers' layoffs. Although the labor law reform in the late 2000s made it easier to use temporary workers and the outbreak of the economic crisis strengthened the power of user firms against labor unions, the size of temporary workers was scaled down. It is the aim of this study to analyze the change in the use of temporary workers, to examine the effect of the labor law reform and that of economic crisis in that regard, and to explain how, over the use of temporary workers, user firms' strategy to secure flexibility and labor unions' strategy to regulate flexibility interact with each other so as to establish a new equilibrium through conflicts and compromises. The labor law reform to enhance the flexibility in the use of temporary workers failed to entail amendments of collective contracts. Besides, out of the economic crisis, user firms adopted a new policy to use third party workers more, refraining from employing temporary workers. That's why the number of temporary workers has declined eventually. User firms prefer to use third party workers because they could avoid their own responsibility as an employer and they could rely on 'permanent temporary' workers without any time limit. Labor unions, however, responded with a strategy to lay more strict regulations on the use of third party workers, so that third party workers could be used only for limited cause for external numerical flexibility. As a result, the managed flexibility thesis comes to prevail to the usage of non-regular workers in general beyond the category of agency workers. Korea with severe abuse of third party workers should learn from Swedish labor unions' strategy to provide third party workers with stronger employment security and higher wages so as to prevent user firms from abusing third party workers.

People's heart-and-mind and the righteous principle in the hostile of circumstances / focusing on Yeheon's Record of Taking Refuge (난중(亂中)의 인심(人心)과 의리(義理) - 여헌(旅軒) 장현광(張顯光)의 『용사일기(龍蛇日記)』를 중심으로 -)

  • Jeon, Byoung-Ok
    • (The)Study of the Eastern Classic
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    • no.57
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    • pp.9-40
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    • 2014
  • This article focuses on Yeheon's consideration and solution for the hostile of social circumstances during the time of the Japanese invasions. Yeheon thought that the Chosun dynasty must have faced such disorder before the war happened. People including the king and his subjects did not live their life according to the righteous principle, and the state was not under control in a way that it should accomplish the Dao. Yeheon thought that the Japanese invasion, which is more like a flood or certain disasters, was not primarily responsible for the harshest of environments. Yeheon paid his attention to the fact that even after the Japanese invasions ended, people were still in disorder losing their mind-and-heart. People's mind-and-heart became that of animals because of starvation and disease. This is because the government made people trapped in a difficult situation by forcing them to prepare for military operations, rather than taking care of them. As a result, in Yeheon's view, the main cause of the social disorder was people's lack of mind-and-heart, which brought about their actions of brutality like those of animals. Although Yeheon himself did not form righteous armies, he instead suggested a right path to overcome and solve the social disorder by describing and analyzing in detail the reality of the war as well as the problems of policies. In particular, Yeheon studied the Zhou yi at the time because understanding the principle of fortune and misfortune, as well as the rise and fall of a state, could give a proper solution to the social turmoil of his times. In Yeheon's eyes, the most important thing to do in the time of people's losing mind-and-heart was to follow li and accomplish the Dao in their daily life. And this was what he, as a gentleman, should do. Yeheon thought that in spite of the harshest of environments, one can still preserve one's grace and dignity, which would overcome one's adversity. This gives us the following questions: should one put aside one's grace and dignity to overcome wartime perils? Or in so doing, one should face more severe time after a short period of peace and stability? These questions concern the relationship between one's morality and the state's responsibility, and what is the right way of doing one's duty to the state is the main philosophical subject in this article.

Understanding the Electrical Property of Si-doped β-Ga2O3 via Thermal Annealing Process (열처리 공정을 이용한 Si-doped β-Ga2O3 박막의 전기적 특성의 이해)

  • Lee, Gyeongryul;Park, Ryubin;Chung, Roy Byung Kyu
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.4
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    • pp.19-24
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    • 2020
  • In this work, the electrical property of Si-doped β-Ga2O3 was investigated via a post-growth annealing process. The Ga2O3 samples were annealed under air (O-rich) or N2 (O-deficient) ambient at 800~1,200℃ for 30 mins. There was no correlation between the crystalline quality and the electrical conductivity of the films within the experimental conditions explored in this work. However, it was observed the air ambient led to severe degradation of the film's electrical conductivity while N2-annealed samples exhibited improvement in both the carrier concentration and Hall mobility measured at room temperature. Interestingly, the x-ray photoemission spectroscopy (XPS) revealed that both annealing conditions resulted in higher concentration of oxygen vacancy (VO). Although it was a slight increase for the air-annealed sample, high resistivity of the film strongly suggests that VO cannot be a shallow donor in β-Ga2O3. Therefore, the enhancement of the electrical conductivity of N2-annealed samples must be originated from something other than VO. One possibility is the activation of Si. The XPS analysis of N2-annealed samples showed increasing relative peak area of Si 2p associated with SiOx with increasing annealing temperature from 800 to 1,200℃. However, it was unclear whether or not this SiOx was responsible for the improvement as the electrical conductivity quickly degraded above 1,000℃ even under N2 ambient. Furthermore, XPS suggested the concentration of Si actually increased near the surface as opposed to the shift of the binding energy of Si from its initial chemical state to SiOx state. This study illustrates the electrical changes induced by a post-growth thermal annealing process can be utilized to probe the chemical and electrical states of vacancies and dopants for better understanding of the electrical property of Si-doped β-Ga2O3.

Effect of Concentration of Nutrient Solution on Water and Nutrient Uptake of Tomato Cultivars in Hydroponics (배양액 농도가 수경재배 토마토의 품종별 생육과 양수분 흡수특성에 미치는 영향)

  • Choi, Gyeong Lee;Yeo, Kyung Hwan;Choi, Su Hyun;Jeong, Ho Jeong;Kang, Nam Jun
    • Journal of agriculture & life science
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    • v.53 no.1
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    • pp.13-21
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    • 2019
  • This study was carried out to acquire basic data for a long-term hydroponic culture through investigating water and inorganic ion uptake characteristics at different EC level of nutrient solution of three tomato varieties. Three different tomato varieties, the European type(cv. Daphnis), the Asian type(cv. Super Doterang) and cherry type(cv. Minichal), were used for the investigation. Also, the deep flow technique(DFT) was applied. The three different electrical conductivity(EC) level(1.0, 2.0, 3.0, and 4.0 dS·m-1) of hydroponic nutrient solution were used as variable. At a high EC level of nutrient solution, the leaf area and fresh weight decreased in the early stage, and its growth(plant height, leaf number, leaf area, fresh-weight) was poor with salt stress. Result showed that the higher the EC level of the nutrient solution, the lesser was water uptake. The water uptake was not significantly different from varieties in the first survey, but In the second survey, the 'Daphnis' did not show a significant decrease in water uptake in the EC level higher than 2.0 dS·m-1., on the other hand, 'Super Doterang' presented very low water uptake. At a low EC level, N, P, and K, were absorbed more than the concentration of the irrigation water, while Ca, Mg, S uptake were low. At a high EC level, almost ions absorbed less than 50% of the initial concentration of irrigation water. Thus, imbalance among ions was severe at low EC level compared to high EC level. 'Daphnis' was a variety that effectively utilize nutrients under nutrient stress, showing high absorption at low concentration condition and low absorption at high concentration condition. However, 'Daphnis' suffered most seriously by absorbing nutrients excessively.

Stability and Damage Evaluation of the Buddha Triad and 16 Rock-Carved Arhat Statues at Seongbulsa Temple in Cheonan, Korea (천안 성불사 마애석가삼존과 16나한상의 손상도 및 안정성 평가)

  • Yang, Hyeri;Lee, Chan Hee;Jo, Young Hoon
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.78-99
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    • 2020
  • The Buddha triad and 16 Arhat statues carved on the rock surface at Seongbulsa temple is the only domestic remaining example of all 16 Arhats, so its academic value is very high. However, it is severely damaged and so required a stability evaluation through study of digital documentation and precise diagnosis for the purpose of comprehensive conservation. This process established that the Buddha statues were of similar scale, while the Arhats showed a wide variety of sizes, and the two kith and kin in the volume were larger than the Arhats. It was estimated that the statues of food for Buddha are similar to the Arhat statues, and most of the statues are well-formed. The rock used to carve the Buddha statues is banded gneiss with distinct foliation, alternating between white bands of quartz and feldspar and black bands composed of biotite. The Buddha statues have been damaged by physical weathering, discoloration, and biological contamination. In damage evaluations, joint (3.6 crack index), peeling (5.2%), exfoliation (1.7%), and falling off (0.1%) were observed on the rock surface of the Buddha statues. In particular, due to severe biological weathering, stage 9 and 10 biological coverage of the rock surface accounted for 57.5% of the total area, and stages 5 to 8 also accounted for a high share at 22.3%. The discoloration factors were shown to be dark brown and white with Fe, Ca, and S, and a large amount of C detected in the blackened contaminants, and the damage weight high in all areas. Discontinuities in different directions were identified in the rock surface. Analysis of potential rock failure types indicated that there is a possibility of plane and toppling failure, but wedge failure is unlikely to occur. The mean ultrasonic velocity of the main rock surface was 2,463m/sec, the lower part of the left side with a large number of joints was relatively low, and the highly weathered (HW) type to the completely weathered (CW) type concentrated distribution, showing weak properties. For the Buddha statues, conservation treatment is required for about 14.9% of micro cracks and 58.9% of exfoliation cracks. In addition, in order to improve the conservation environment of the Buddha statues, maintenance of drainage and ground preparations for the rock surface gradient and plants are necessary, and protection facilities should be reviewed for long-term conservation and management purposes.