• Title/Summary/Keyword: k-opt

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Optimal Design of Blade Shape for 200-kW-Class Horizontal Axis Tidal Current Turbines (200kW급 수평축 조류발전 터빈 블레이드 형상 최적설계)

  • Seo, JiHye;Yi, Jin-Hak;Park, Jin-Soon;Lee, Kwang-Soo
    • Journal of Ocean Engineering and Technology
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    • v.29 no.5
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    • pp.366-372
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    • 2015
  • Ocean energy is one of the most promising renewable energy resources. In particular, South Korea is one of the countries where it is economically and technically feasible to develop tidal current power plants to use tidal current energy. In this study, based on the design code for HARP_Opt (Horizontal axis rotor performance optimizer) developed by NREL (National Renewable Energy Laboratory) in the United States, and applying the BEMT (Blade element momentum theory) and GA (Genetic algorithm), the optimal shape design and performance evaluation of the horizontal axis rotor for a 200-kW-class tidal current turbine were performed using different numbers of blades (two or three) and a pitch control method (variable pitch or fixed pitch). As a result, the VSFP (Variable Speed Fixed Pitch) turbine with three blades showed the best performance. However, the performances of four different cases did not show significant differences. Hence, it is necessary when selecting the final design to consider the structural integrity related to the fatigue, along with the economic feasibility of manufacturing the blades.

An Optimal Algorithm for Stable Marriage Problem (안정된 결혼문제에 대한 최적화 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.4
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    • pp.149-154
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    • 2018
  • There is well known algorithm is a Gale-Shapley algorithm(GSA) for stable marriage problem. The GSA is performed as each man propose to his most favorite woman(MP), then the woman accepts more than one proposal rejects all but her favorite from among those who have proposed to her. This algorithm always gets a stable set of marriages with man-optimal and woman-pessimal. But the woman proposal and man-accept/reject method(WP) is can be get the distinct result. Also, the optimal stable matching may be fail using MP or WP. This paper suggests always get the optimal stable matching on all occasions in order to overcome the shortcomings of MP and WP. The proposed algorithm perform k-opt, k-women exchange with each other for the result of delete at less preference in each woman from MP result. As a result of applied to various experimental data, this algorithm can be get the optimal stable matching that the MP or WP failed to it.

A study of ribonuclease activity in venom of vietnam cobra

  • Nguyen, Thiet Van;Osipov, A.V.
    • Journal of Animal Science and Technology
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    • v.59 no.9
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    • pp.20.1-20.9
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    • 2017
  • Background: Ribonuclease (RNase) is one of the few toxic proteins that are present constantly in snake venoms of all types. However, to date this RNase is still poorly studied in comparison not only with other toxic proteins of snake venom, but also with the enzymes of RNase group. The objective of this paper was to investigate some properties of RNase from venom of Vietnam cobra Naja atra. Methods: Kinetic methods and gel filtration chromatography were used to investigate RNase from venom of Vietnam cobra. Results: RNase from venom of Vietnam cobra Naja atra has some characteristic properties. This RNase is a thermostable enzyme and has high conformational stability. This is the only acidic enzyme of the RNase A superfamily exhibiting a high catalytic activity in the pH range of 1-4, with $pH_{opt}=2.58{\pm}0.35$. Its activity is considerably reduced with increasing ionic strength of reaction mixture. Venom proteins are separated by gel filtration into four peaks with ribonucleolytic activity, which is abnormally distributed among the isoforms: only a small part of the RNase activity is present in fractions of proteins with molecular weights of 12-15 kDa and more than 30 kDa, but most of the enzyme activity is detected in fractions of polypeptides, having molecular weights of less than 9 kDa, that is unexpected. Conclusions: RNase from the venom of Vietnam cobra is a unique member of RNase A superfamily according to its acidic optimum pH ($pH_{opt}=2.58{\pm}0.35$) and extremely low molecular weights of its major isoforms (approximately 8.95 kDa for RNase III and 5.93 kDa for RNase IV).

Studies on Microbial Inulase (Part I) -A Study on the Isolation of an Inulase Producing strain and the Optimum Cultural Conditions for the Enzyme Production- (미생물(微生物) Inulase에 관한 연구(硏究) 제1보(第一報) -Inulase생산균주(生産菌株)의 분리(分離)와 효소생산(酵素生産)을 위한 배양조건(培養條件)의 검토(檢討)-)

  • Kim, Ki-Choul
    • Applied Biological Chemistry
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    • v.18 no.1
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    • pp.42-51
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    • 1975
  • Penicillium sp I which produces a powerful hydrolysing enzyme was isolated from putrefid and dry Jerusalem artichoke medium. The strain was used to study on the optimum culture conditions for enzyme production. The results obtained are as follows: 1. Penicillium sp I was a vigorous strain to produce inulase. 2. The optimum culture conditions of the strain was examined in the Jerusalem artichoke extract medium and the synthetic medium. 3. Inulase productivity in the Jerusalem artichoke extract medium was higher than that of the synthetic medium. 4. The optimum culture period of the Jerusalem artichoke extract medium was four days, whereas that of the synthetic medium was five days. 5. The optimum temperature, pH and concentration in the Jerusalem artichoke extract medium were $30^{\circ}C$, 5.0 and 4.0% (W/V), respectively. Meanwhile, the optimum temperature, pH and concentration in the synthetic medium were $30{\sim}33^{\circ}C$, $5.0{\sim}6.0$, and $1.0{\sim}1.5%$ (W/V), respectively. 6. Corn steep liquor, peptone, $(NH_4)_2HPO_4,\;NH_4H_2PO_4,\;(NH_4)_2SO_4$, etc. were favorable as nitrogen sources. Of these, especially, Corn steep liquor and peptone as organic nitrogen sources caused an increase in inulase production in the synthetic medium. 7. All sugars except for inulin have no effect upon the inulase production. 8. KCl, $MgSO_4\;and\;FeSO_4$ were favourable mineral sources for inulase production.

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Antioxidative effects of Kimchi under different fermentation stage on radical-induced oxidative stress

  • Kim, Boh Kyung;Choi, Ji Myung;Kang, Soon Ah;Park, Kun Young;Cho, Eun Ju
    • Nutrition Research and Practice
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    • v.8 no.6
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    • pp.638-643
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    • 2014
  • BACKGROUND/OBJECTIVES: Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. MATERIALS/METHODS: Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress of kimchi during fermentation were investigated under in vitro and cellular systems using LLC-$PK_1$ cells. RESULTS: Kimchi exhibited strong radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, superoxide anion, and hydroxyl radical. In addition, the free radical generators led to loss of cell viability and elevated lipid peroxidation, while treatment with kimchi resulted in significantly increased cell viability and decreased lipid peroxidation. Furthermore, the protective effect against oxidative stress was related to regulation of cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-${\kappa}B$ p65, and $I{\kappa}B$ expression. In particular, OvR showed the strongest protective effect from cellular oxidative stress among other kimchi. CONCLUSION: The current study indicated that kimchi, particularly OptR and OvR, played a protective role against free radical-induced oxidative stress. These findings suggest that kimchi is a promising functional food with an antioxidative effect and fermentation of kimchi led to elevation of antioxidative activity.

The Farnesyl Protein Transferase Inhibition Activity of Chalcone Derivatives (Chalcone 유도체의 Farnesyl Protein Transferase 저해활성)

  • Yu, Seong-Jae;Myung, Pyung-Keun;Kwon, Byung-Mok;Lee, Seung-Ho;Sung, Nack-Do
    • Applied Biological Chemistry
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    • v.42 no.3
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    • pp.252-255
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    • 1999
  • Inhibition activities$(pI_{50})$ of chalcone derivatives as substrate with farnesyl protein transferase(FPTase) were determined in vitro. The structure activity relationships(SAR) between the activity and physicochemical parameters of X & Y-substituents on the phenyl groups were analyzed by Free-Wilson and Hansch method. X-substituents on the benzoyl group have the more important role to inhibition activity than Y-substituents on the styryl group. Among them, none substituent, 8 showed the highest FPTase inhibition activity$(pI_{50}=4.30)$. Particularly, the SAR equation could be formulated, showing a parabolic relationship between the activity and hydrophobicity(logP) where the optimal value$({\Sigma}logP)_{opt}$ was 3.915. And also the activity depends on the steric effect(Es > 0) with X-substituent and the resonance effect(R < 0) with electron donating Y-substituents. Based on the results of SAR analyses, the interactions between substrates and receptor, FPTase, could be assumed.

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Implications for the CISG's Applicability concerning U.S. Court's Cases (미국법원의 판례를 통한 CISG 적용상의 함의)

  • Han, Na-hee;Ha, Choong-lyong
    • International Commerce and Information Review
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    • v.18 no.4
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    • pp.195-217
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    • 2016
  • The Convention on Contracts for the International Sale of Goods(CISG) endeavors to increase international trade through the creation of a uniform law of international sales. The CISG applies to contracts of sale of goods between parties whose places of business are in different States. If a party has more than one place of business, the place of business if that which has the closest relationship to the contract and its performance. Despite the importance of a definition for 'place of business,' the CISG does not provide one. Lack of a definition of 'place of business' may cause problems for parties trying to determine whether the CISG applies to their contract. Also Contracting parties can opt out of the CISG. But the CISG does not state whether the parties must expressly exclude the CISG's application to a transaction or whether they might do so by implication. we need to consider how effectively opt out of the CISG. Under U.S. law, the CISG is considered to be a self-executing treaty. So the CISG's provisions apply directly as substantive sales law to contracts for the international sale of goods. Despite the CISG's political and economic significance to U.S., U.S. Courts have overlooked the terms of the CISG. This article considered how to the CISG was recognized, interpreted and applied by the U.S. Courts in related cases.

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Technologies for 3D Assembly and Chip-level Stack

  • Bonkohara, Manabu
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.09a
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    • pp.65-89
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    • 2003
  • Next Highly sophisticated communication generation of the Advanced Electronics and Imaging processing society will require a vast information volume and super high speed signal transport and information instruction. This means that super high technology should be created for satisfying the demand. It's also required the high reliability of the communication system itself, It will be supported the new advanced packaging technology of the 3 Dimensional structured system and system integration technology. Here is introduced the new 3 Dimensional technology for IC nnd LSI packaging and Opt-electronics Packaging of ASET activity in Japan.

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Physical-Mechanical Properties of Laminated Board Made from Oil Palm Trunk (Elaeis guineensis Jacq.) Waste with Various Lamina Compositions and Densifications

  • PRABUNINGRUM, Dita Sari;MASSIJAYA, Muh Yusram;HADI, Yusuf Sudo;ABDILLAH, Imam Busyra
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.2
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    • pp.196-205
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    • 2020
  • The purpose of this study was to investigate a method for improving the physical and mechanical properties of laminated board made from oil palm trunk (OPT). The effects of pretreating the lamina with heat-pressure and altering the lamina composition of the laminated board were investigated. The outer third of OPT in cross-section had high-density wood, while the underlying third had low to medium density. The hot press was applied to pretreat the lamina that had low to medium density. The lamina were 1.5 cm in thickness, 5 cm in width, and 65 cm in length. The hot press was applied at 2.94 MPa or 4.41 MPa at 150 ℃ for 60 minutes, and the target thickness of the lamina was 1 cm. The three layers of the laminated board samples were bonded with isocyanate adhesive at a glue spread of 300 g/㎡ and cold pressed at 0.98 MPa for 3 h. The laminated board samples were tested according to Japanese Agricultural Standard (JAS) 234-2003. The results showed that the densification of the inner lamina did not significantly affect the physical-mechanical properties of the laminated board produced. However, the laminated board made with high-density laminas for the outer layers fulfilled the JAS 234-2003 standard for the modulus of elasticity and the modulus of rupture.

Preoperative Levels of Hematological and Biochemical Indices Affect Perioperative Variables in Adult Patients with Coronary Artery Bypass Graft Surgery

  • Choi, Seok-Cheol;Cho, Byung-Kyu;Lee, Yong-Hwan;Chang, Kyung-Soo
    • Biomedical Science Letters
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    • v.16 no.4
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    • pp.247-258
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    • 2010
  • The objective of this research was to evaluate the relationships of preoperative (Pre-OP) levels of hematological and biochemical indices to perioperative variables in patients that underwent coronary artery bypass graft surgery (CABG). Pre-OP levels of hematological factors [total white blood cells (T-WBC), erythrocytes, hemoglobin, hematocrit, glycohemoglobin A1c (HbA1c), or platelet] were negatively or positively related with biochemical indices [alanine aminotransferase (ALT), bilirubin, glucose, fructosamine, triglyceride, and high density lipoprotein cholesterol (HDL)]. Pre-OP levels of hematological factors and biochemical indices were negatively or positively correlated with echocardiographic variables. Pre-OP level of HbA1c had a relationship with C-reactive protein. Pre-OP levels of aspartate aminotransferase (AST), ALT, HDL, glucose, fructosamine, or blood urea nitrogen (BUN) were positively or negatively associated with Pre-OP levels of cardiac markers (brain natriuretic peptide, troponin-I, creatine kinase isoenzyme 2, or CRP). Pre-OP levels of hematological factors (excepting T-WBC) related with operation time (OPT), postoperative mechanical ventilation time (POMVT), intensive care unit-period (ICU-period) or hospitalization. Pre-OP levels of AST, ALT, bilirubin, triglyceride, HDL, low dwensity lipoprotein, fructosamine, or BUN were positively or negatively correlated with OPT, graft numbers, POMVT, ICU-period or hospitalization. Retrospective this study reveals that Pre-OP levels of hematological and biochemical markers are associated with echocardiographic variables, several cardiac markers and postoperative outcomes, suggesting that Pre-OP levels of hematological and biochemical markers may be useful predictors for the diagnosis and prognosis of coronary artery disease.