• Title/Summary/Keyword: Power system control

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Global Value Chains and Creating Shared Value in Vietnamese Coffee Frontier (베트남 커피변경지역의 글로벌 가치사슬과 공유가치 창출)

  • Lee, Sung-Cheol;Chung, Su-Yuel;Joh, Young-Kug
    • Journal of the Economic Geographical Society of Korea
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    • v.19 no.2
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    • pp.399-416
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    • 2016
  • The main aim of the research attempts to identify value relations appropriated and realized in the coffee frontier of Vietnam by investigating the ways in which it is integrated into coffee global value chains driven by multinational companies, and to provide some implications of the integration of the frontier into sustainable coffee global value chains for creating shared value in Dak Lak, Vietnam. Recently Dak Lak has gone through the transition of value relations from exploitative value chains based upon conventional coffee production into shared value chains relied upon the production of sustainable or certified coffee in Dak Lak. The transition has been expected to result in sustainability in the creation of value by enhancing regional competitive advantages and regional bargaining power in global value chains driven by multinational companies. However, the reality has shown the intensification of hierarchical profits allocation among stakeholders such as farmer, middlemen, and multinational companies in the region. The main reasons for this could be found in two perspectives. Firstly, the formation of exclusive relations among farmers, middlemen, and processors has led to stakeholders to secure market, but resulted in the intensification of hierarchy among them in global value chain, because multinational companies could control indirectly over the farming system through exclusive middlemen. Secondly, social and ecological costs imputed by multinational companies to coffee farmers in the name of creating shared value has deteriorated the economic profits of stakeholders such as farmers and middlemen. As a result, it has led to the configuration of systematically hierarchical and subordinated global value chain in Dak Lak.

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Whitening and Anti-wrinkle Effects of Apple Extracts (사과 추출물의 미백 및 주름개선 효과)

  • Jeong, Hee-Rok;Jo, Yu-Na;Jeong, Ji-Hee;Jin, Dong-Eun;Song, Byung-Gi;Heo, Ho-Jin
    • Food Science and Preservation
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    • v.18 no.4
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    • pp.597-603
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    • 2011
  • The in-vitro whitening and anti-wrinkle effect of ethanol extracts from apple flesh and peel were investigated. The EtOAc fractions from the ethanol extracts of apple flesh and peel showed in-vitro antioxidant activities in a dose-dependent manner on ABTS radical-scavenging activity and ferric-reducing/antioxidant power, and had the highest total phenolic contents (84.25 and 318.25 mg GAE/g). In addition, the EtOAc fractions generally showed strong UV absorption within the UV-B range. In the cellular system, the melanin synthesis of the B16/F10 melanoma cells was decreased by the EtOAc fractions of apple peel in a concentration-dependent manner. The EtOAc fractions of apple peel also showed a great elastase inhibition of 46.40% at 100 ${\mu}g$/mL, thus showing good in-vitro anti-wrinkle characteristics. These results suggest that the EtOAc fractions from the ethanol extract of apple peel can be used as whitening and anti-wrinkle agents as well as antioxidant resources.

Factors Affecting Job-Seeking Stress in Nursing Students (간호대학생의 취업 스트레스에 영향을 미치는 요인)

  • Choe, Myeong Hui;Kim, Joo Hyun;Nam, Eun Sook;Lee, Yong Mi;Hwang, Ju Hee;Lee, Mi Kyung;Yoon, Sung Ja;Park, Hyunju
    • Korean Journal of Occupational Health Nursing
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    • v.24 no.2
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    • pp.122-131
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    • 2015
  • Purpose: The purpose of this study was to investigate what factors are affecting job-seeking stress in nursing students. Methods: Subjects were 463 students from two 3-year and two 4-year colleges of nursing in K-Province in Korea. Data was collected from self-administered questionnaires. t-test, ANOVA, Pearson's and Spearman's correlation coefficients, and hierarchical multiple regression with dummy variables were used for statistical analysis of data. Results: Job-seeking stress was significantly different by school system (t=2.76, p=.006), family economic status (F=3.40, p=.005), characteristics (t=1.99, p=.047), academic achievement (F=6.54, p=.002), current weight control status (t=2.23, p=.026), times of cosmetic surgery (r=.11, p=.022), self-esteem (r=-.47, p<.001) and appearance stress (r=.40, p<.001). However, after controlling for general characteristics, self-esteem, and perceived appearance stress, job-seeking stress was significantly different by grade (1st vs 3rd, ${\beta}=0.163$, p<.001), academic achievement (low vs. high, ${\beta}=-0.121$, p=.0321), self-esteem (${\beta}=-0.224$, p<.001), and appearance stress (${\beta}=0.099$, p<.001). The explanation power of self-esteem on job-seeking stress was greater compared with that of appearance stress. Conclusion: Results of this study suggest that it is necessary for nursing students to develop intervention program aimed at reducing job-seeking stress, and it would be effective to focus on improving self-esteem for them.

Quality characteristics of steamed rice cake with Schisandra chinensis powder or extract added prior to storage (오미자 분말 및 추출물 첨가 설기떡의 저장 중 품질특성)

  • Kim, Dae-Hyun;Cho, Jeong-Seok;Park, Jung-Hoon;Kim, Jae-Hwan;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.23 no.7
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    • pp.923-930
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    • 2016
  • The purpose of this study was to improve the quality of the steamed rice cakes added with powder and extract of Schisandra chinensis (SC). Steamed rice cakes were prepared by adding SC using 1% hot-air dried SC powder (DP), hot-air dried SC extract (DE), freeze dried SC powder (FP) and, frozen SC extract (FE). After packaging with nylon/polyethylene films, the cakes were stored at $25^{\circ}C$ for 5 days. The FE-treated steamed rice cake had the lowest pH value. The $L^*$ value of the control cakes was highest immediately after processing and decreased during storage. The $a^*$ values of FP- and FE-treated steamed rice cakes were higher than those of DP- and DE-treated cakes. The $b^*$ values of DP- and DE-treated steamed rice cakes were higher than those of FP- and FE-treated cakes. Total phenolic contents of DP and DE were lower than those of FP and FE. Anthocyanin contents of DP- and DE-treated steamed rice cakes were lower than those of FP- and FE-treated cakes. Schisandrin contents of DP- and FP-treated steamed rice cakes were lower than those of DE- and FE-treated cakes. Ferric reducing antioxidant power assays revealed that DP and DE had lower antioxidant powers than those of FP and FE. The results of this study indicate that, among the treatments methods used, the steamed rice cake treated with FE had the highest functional component and antioxidant activity levels.

Design of an Optimal Adaptive Filter for the Cancellation of M-wave in the EMG Controlled Functional Electrical Stimulation for Paralyzed Individuals (마비환자의 근전도제에기능적전기자극을 위한 M-wave 제거용 최적적응필터 설계)

  • Yeom Hojoon;Park Youngcheol;Lee Younghee;Yoon Youngro;Shin Taemin;Yoon Hyoungro
    • Journal of Biomedical Engineering Research
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    • v.25 no.6
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    • pp.479-487
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    • 2004
  • Biopotential signals have been used as command in systems using electrical stimulation of motor nerves to restore movement after an injury to the central nervous system (CNS). In order to use the voluntary EMG (electromyography) among the biopotentials as a control signal for the electrical stimulation of the same muscle for CNS injury patients, it is necessary to remove M-wave of having high magnitude from raw data. We designed an optimal filter for removing the M-wave and preserving the voluntary EMG and showed that the optimal filter is eigen filter. We also proved that the previous method using the prediction error filter(PEF) is a suboptimal filtering in the sense of preserving the voluntary EMG. On basis of the data obtained from a model for M-wave and voluntary EMG and from actual CNS injury patients, with false-positive rate analysis, the proposed adaptive filter showed a very promising performance in comparison with previous method.

NIRS Analysis of Liquid and Dry Ewe Milk

  • Nunez-Sanchez, Nieves;Varo, Garrido;Serradilla-Manrique, Juan M.;Ares-Cea, Jose L.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1251-1251
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    • 2001
  • The routine analysis of milk chemical components is of major importance both for the management of animals in dairy farms and for quality control in dairy industries. NIRS technology is an analytical technique which greatly simplifies this routine. One of the most critical aspects in NIRS analysis of milk is sample preparation and analysis modes which should be fast and straightforward. An important difficulty when obtaining NIR spectra of milk is the high water content (80 to 90%) of this product, since water absorbs most of the infrared radiation, and, therefore, limits the accuracy of calibrating for other constituents. To avoid this problem, the DESIR system was set up. Other ways of radiation-sample interaction adapted for liquids or semi-liquids exist, which are practically instantaneous and with limited or null necessity of sample preparation: Transmission and Folded Transmission or Transflectance. The objective of the present work is to compare the precision and accuracy of milk calibration equations in two analysis modes: Reflectance (dry milk) and Folded Transmission (liquid milk). A FOSS-NIR Systems 6500 I spectrophotometer (400-2500 nm) provided with a spinning module was used. Two NIR spectroscopic methods for milk analysis were compared: a) folded transmission: liquid milk samples in a 0.1 pathlength sample cell (ref. IH-0345) and b) reflectance: dried milk samples in glass fibre filters placed in a standard ring cell. A set of 101 milk samples was used to develop the calibration equations, for the two NIR analysis modes, to predict casein, protein, fat and dry matter contents, and 48 milk samples to predict Somatic Cell Count (SCC). The calibrations obtained for protein, fat and dry matter have an excellent quantitative prediction power, since they present $r^2$ values higher than 0.9. The $r^2$ values are slightly lower for casein and SCC (0.88 and 0.89 respectively), but they still are sufficiently high. The accuracy of casein, protein and SCC equations is not affected by the analysis modes, since their ETVC values are very similar in reflectance and folded transmission (0.19% vs 0.21%; 0.16% vs 0.19% and 55.57% vs 53.11% respectively), Lower SECV values were obtained for the prediction of fat and dry matter with the folded transmission equations (0.14% and 0.25% respectively) compared to the results with the reflectance ones (0.43% and 0.34% respectively). In terms of accuracy and speed of analytical response, NIRS analysis of liquid milk is recommended (folded transmission), since the drying procedure takes 24 hours. However, both analysis modes offer satisfactory results.

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A Study of Energy Security Cooperation and its Integration Potential in South America through Brazilian Leadership (남미지역 에너지안보 협력과 통합 가능성 연구 : 브라질의 리더십 역할 고찰)

  • Ha, Sang-Sub
    • Journal of International Area Studies (JIAS)
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    • v.15 no.1
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    • pp.83-108
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    • 2011
  • South America has vast energy resources with the renewable and non-renewable sources. However, many countries in the region are unable to guarantee adequate energy security both of energy supply and demand. Currently the possibility of energy security is high through regional energy integration based on the potential economic benefits. The difference of regulation system with the individual countries in the region impose strong barriers to integration process. Security of energy supply and its demand as well is fundamental issues in this region and regional energy cooperation is essential for getting rid of the insecurity of energy supplies. Despite of this problem, currently Latin American countries made a great effort to make multilateral energy security regime through projecting great energy infrastructure network(e.g. IIRSA) or mechanism especially in South America, which can give countries access to the region's reserve supplies by providing regulations and pricing mechanism with a shared energy market in this region. Brazil's active leading in the formulation of such movement toward energy security integration and participation of energy infrastructure network is good initiative to enforce this great energy security change. Politically and economically, Brazil's geographical position and the level of market size and oil and natural gas resources, in addition the leadership in renewable energy sources make it a sound candidate to take over the coordination of the secure integration of region's energy market. However, on the conditions of existing many obstacles such as, control of the output of the region's power plant, energy flows, the environmental matter within local community must be overcome to make more advance process and steps. Finally, to secure more institutional approach, this region must settle regional disputes resolution regime urgently.

Serum exosomal miR-192 serves as a potential detective biomarker for early pregnancy screening in sows

  • Ruonan Gao;Qingchun Li;Meiyu Qiu;Su Xie;Xiaomei Sun;Tao Huang
    • Animal Bioscience
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    • v.36 no.9
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    • pp.1336-1349
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    • 2023
  • Objective: The study was conducted to screen differentially expressed miRNAs in sows at early pregnancy by high-throughput sequencing and explore its mechanism of action on embryo implantation. Methods: The blood serum of pregnant and non-pregnant Landrace×Yorkshire sows were collected 14 days after artificial insemination, and exosomal miRNAs were purified for high throughput miRNA sequencing. The expression patterns of 10 differentially expressed (DE) miRNAs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR quantified the abundance of serum exosomal miR-192 in pregnant and control sows, and the diagnostic power was assessed by receiver operating characteristic (ROC) analysis. The target genes of DE miRNAs were predicted with bioinformatics software, and the functional and pathway enrichment analysis was performed on gene ontology and the Kyoto encyclopedia of genes and genomes terms. Furthermore, a luciferase reporter system was used to identify the target relation between miR-192 and integrin alpha 4 (ITGA4), a gene influencing embryo implantation in pigs. Finally, the expression levels of miRNAs and the target gene ITGA4 were analyzed by qRT-PCR, and western blot, with the proliferation of BeWo cells detected by cell counting kit-8 (CCK-8). Results: A total of 221 known miRNAs were detected in the libraries of the pregnant and non-pregnant sows, of which 55 were up-regulated and 67 were down-regulated in the pregnant individuals compared with the non-pregnant controls. From these, the expression patterns of 10 DE miRNAs were validated. The qRT-PCR analysis further confirmed a significantly higher expression of miR-192 in the serum exosomes extracted from pregnant sows, when compared to controls. The ROC analysis revealed that miR-192 provided excellent diagnostic accuracy for pregnancy (area under the ROC curve [AUC]=0.843; p>0.001). The dual-luciferase reporter assay indicated that miR-192 directly targeted ITGA4. The protein expression of ITGA4 was reduced in cells that overexpressed miR-192. Overexpression of miR-192 resulted in the decreased proliferation of BeWo cells and regulated the expression of cell cycle-related genes. Conclusion: Serum exosomal miR-192 could serve as a potential biomarker for early pregnancy in pigs. miR-192 targeted ITGA4 gene directly, and miR-192 can regulate cellular proliferation.

Adaptive RFID anti-collision scheme using collision information and m-bit identification (충돌 정보와 m-bit인식을 이용한 적응형 RFID 충돌 방지 기법)

  • Lee, Je-Yul;Shin, Jongmin;Yang, Dongmin
    • Journal of Internet Computing and Services
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    • v.14 no.5
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    • pp.1-10
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    • 2013
  • RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

Development of a Mobile Tower-yarder with Tractor (I) - Design and Manufacture - (트랙터부착형 타워집재기 개발(I) - 설계 및 제작-)

  • Park, Sang-Jun;Kim, Bo-Kyun
    • Journal of Korean Society of Forest Science
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    • v.97 no.1
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    • pp.61-70
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    • 2008
  • This study was conducted to develop a mobile tower-yarder with tractor for agriculture and forestry that is the efficient yarder in steep terrains, thinning operation and small scale logging operation. It was designed and manufactured that the power source of tower-yarder is equiped three hydraulic pump connected to PTO of tractor, and three hydraulic pump is used to operate the four motor for drum, the cylinder for clutch of interlocker, the cylinder for tower expanding and the out-rigger cylinder. It was to adopt the running skyline system and the inter-lock function, and to equip the double capstan drum, the storage drum and the clutch for interlock in the development of tower-yarder. It was to develop the tower-yarder which the winch torque of double-capstan drum, the traction force of double-capstan drum, the number of rotation of double-capstan drum and the line speed is $191kg{\cdot}m$, 1,910 kgf, 220.5 rpm and 138.5 m/min, respectively. And it was known that the optimum flange diameter of the main and haulback storage drum is about 360 mm and about 460 mm in order to storage the main line length of 250m and the haulback line length of 450 m. The carriage was made to adopt the running skyline system and to equip the lock function in order to the convenience of chocking and the fall down preventing of tree. It was provided to develop the wire remote controller for the inter-lock function, the convenience of control and the efficiency of yarding. In development process, this tower-yarder was attached the 3-point linkage hitch equipment and the tire wheel for the traction and moving of tower-yarder. Also, it was equipped that the out-rigger and the guy line in order to raise the safety and efficiency of yarding of tower-yarder.