• Title/Summary/Keyword: Hv

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A Study on Methodology to Improve the Power Factor of the High Power LED Module (고출력 LED 모듈 역률 개선 방법 연구)

  • Lho, Young Hwan
    • Journal of IKEEE
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    • v.18 no.3
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    • pp.335-340
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    • 2014
  • Recently, LED (Light Emitting Diode) becomes to be useful to apply for the lightening sources in electric systems and the lightening equipment since the power is less consumed with high efficiency, and the size and the weight of LED are small and light, respectively. The LED is controlled with constant current and SMPS (Switching Mode Power Supply). It is necessary for the LED manufacturer to secure the fundamental technology of designing LED chip, and to study the methodology to improve the power factor (PF) and to design the operational circuit for the development of LED to reduce the power loss in the application of LED lightening. The direct AC (Alternating Current) LED driving circuit, HV9910, is widely used in the industry field. In this paper, it is to evaluate the improved methodology for the power factor and efficiency through simulations when PFC (Power Factor Correction) and Noise Filter are added to HV9910.

The Treatment for Hallux Valgus with Scarf Osteotomy in Elderly Patients with Osteoporosis (골다공증이 있는 고령의 환자에서 Scarf 중족골 절골술을 이용한 무지 외반증의 치료)

  • Hwang, Seung Hyun;Lee, Su Chan;Nam, Chang Hyun;Baek, Ji-Hoon;Ahn, Hye Sun
    • Journal of Korean Foot and Ankle Society
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    • v.21 no.3
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    • pp.93-97
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    • 2017
  • Purpose: The aim of this study was to evaluate the radiological and clinical outcomes of scarf osteotomy for hallux valgus (HV) deformity in elderly patient with osteoporosis. Materials and Methods: A total of 58 elderly patients (mean age, 72.6 years) underwent scarf osteotomy for HV deformity between 2008 and 2015. The mean follow-up period was 24.4 months. Of the 58 patients, 42 were diagnosed with osteoporosis and 16 were diagnosed as normal. The radiological and clinical outcomes were assessed preoperatively, postoperatively, and at final follow-up, including HV angle, intermetatarsal (IM) angle, American Orthopaedic Foot and Ankle Society (AOFAS) score, patient satisfaction, visual analogue scale (VAS), and complication. Results: There was no significant difference in HV angle and IM angle between the osteoporosis group and normal bone mineral densitometry group at all time points, preoperative, postoperative, and final follow-up. Moreover, there was no statistically significant difference between the two groups with respect to the AOFAS score and VAS evaluations. In the osteoporosis group, the mean HV angle improved from $36.7^{\circ}$ preoperatively to $11.3^{\circ}$ at the time of final follow-up, and the mean IM angle improved from $13.2^{\circ}$ to $5.7^{\circ}$. The mean AOFAS score improved from 52.6 preoperatively to 89.1 at the time of final follow-up. With respect to satisfaction, 83.4% of patients were very satisfied or satisfied. There were no serious complications, and all cases showed complete union at the osteotomy site. Conclusion: We believed that scarf osteotomy is a safe, effective procedure for the correction of elderly patients with osteoporosis.

Comparison of Histopathology, Serology and PCR for the Diagnosis of Malignant Catarrhal Fever (Malignant Catarrhal Fever의 병리조직학적 진단과 혈청학적 진단 및 PCR 진단법의 비교)

  • Kim, Ok-jin;Crawford, Timothy B.
    • Korean Journal of Veterinary Research
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    • v.43 no.3
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    • pp.471-476
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    • 2003
  • Malignant catarrhal fever (MCF) is a systemic disease of ruminants caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is a gamma herpesvirus, which induces frequent latent infection and often difficult to detect its antigens and even specific nucleic acids because of its low viral copies in the infected tissues. Histopathology, serology and polymerase chain reaction (PCR) were compared for the diagnosis of MCF using 10 bison infected with OvHV-2. Histopathological diagnosis was performed using the criteria which was based upon the pathognomic lesions. Serological diagnosis was conducted using its serum with competitive ELISA for the detection of antibodies of OvHV-2. Also, the nest PCR was performed with peripheral blood leukocytes for the detection of OvHV-2-specific DNAs. Primers 556 and 775 were used for the primary amplification, and primers 556 and 555 were used for the secondary amplification. As the results, positive cases were 6 by histopahology, 9 by serology and 10 by PCR. As comparing with other diagnostic methods, PCR was found to be more sensitive than histopathology and serology. The recent development of molecular diagnostic assays has provided powerful tools for investigating how viruses survive in nature. Development of PCR specific for viruses has dramatically improved the accuracy of diagnosis of viruses in clinically infected animals. Furthermore, amplification of viral genomic material by nest PCR represents the most sensitive method for the detection of viruses and might be detected successfully even though very low viral DNA copies. So, it could be used as the first choice for the detection of viral DNAs with low copies such as the status of latent infection. However, it has also some limitation of application like as false negative results by PCR inhibitors and false positive results by contamination. The results of this study suggest that the use of molecular biological methods like PCR may increase the accuracy for the diagnosis of infectious diseases. However, in diagnostic laboratory, it is recommended that PCR assay must be conducted with other diagnostic methods for more reliable diagnosis.

Biometric Authentication Protocol Using Hidden Vector Key Encapsulation Mechanism (HV-KEM을 이용한 생체 정보 기반 인증 프로토콜)

  • Seo, Minhye;Hwang, Jung Yeon;Kim, Soo-hyung;Park, Jong Hwan
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.26 no.1
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    • pp.69-79
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    • 2016
  • Biometric authentication is considered as being an efficient authentication method, since a user is not required to possess or memorize any other information other than biometrics. However, since biometric information is sensitive and could be permanently unavailable in case of revealing that information just once, it is essential to preserve privacy of biometrics. In addition, since noise is inherent in the user of biometric recognition technologies, the biometric authentication needs to handle the noise. Recently, biometric authentication protocols using fuzzy extractor have been actively researched, but the fuzzy extractor-based authentication has a problem that a user should memorize an additional information, called helper data, to deal with their noisy biometric information. In this paper, we propose a novel biometric authentication protocol using Hidden Vector Key Encapsulation Mechanism(HV-KEM) which is one of functional encryption schemes. A primary advantage of our protocol is that a user does not need to possess or memorize any additional information. We propose security requirements of HV-KEM necessary for constructing biometric authentication protocols, and analyze our proposed protocol in terms of correctness, security, and efficiency.

Isolation of a Pseudomonas sp. Strain Exhibiting Unusual Behavior of Poly(3-hydroxyalkanoates) Biosynthesis and Characterization of Synthesized Polyesters

  • Chung, Chung-Wook;Kim, Yoon-Seok;Kim, Young-Baek;Bae, Kyung-Sook;Rhee, Young-Ha
    • Journal of Microbiology and Biotechnology
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    • v.9 no.6
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    • pp.847-853
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    • 1999
  • A Pseudomonas sp. strain that is capable of utilizing dicarboxylic acids as a sole carbon source was isolated from activated sludge by using the enrichment culture technique. This organism accumulated polyhydroxyalkanoates (PHAs) with an unusual pattern of monomer units that depends on the carbon sources used. Polyhydroxybutyrate (PHB) homopolyester was synthesized from glucose or small $C_{-even}$ alkanoic acids, such as butyric acid and hexanoic acid. Accumulation of PHB homopolyester was also observed in the cells grown on $C_{-odd}$ dicarboxylic acids, such as heptanedioic acid and nonanedioic acid as the sole carbon sources. In contrast, a copolyester consisting of 6 mol% 3-hydroxybutyrate (3HB) and 94 mol% 3-hydroxyvalerate (3HV) was produced with a PHA content of as much as 36% of the cellular dry matter. This strain produced PHAs consisting both of the short-chain-length (SCL) and the medium-chain-length (MCL) 3-hydroxyacid units when heptanoic acid to undecanoic acid were fed as the sole carbon sources. Most interestingly, polyester consisting of significant amount of relevant fractions, 3HB, 3HV, and 3-hydroxyheptanoate (3HHp), was accumulated from heptanoic acid. According to solvent fractionation experiments, the polymer produced from heptanoic acid was a blend of poly(3HHp) and of a copolyester of 3HB, 3HV, and 3HHp units. The hexane soluble fractions contained only 3HHp units while the hexane-insoluble fractions contained 3HB and 3HV units with a small amount of 3HHp unit. The copolyester was an elastomer with unusual mechanical properties. The maximum elongation ratio of the copolyester was 460% with an ultimate strength of 10 MPa, which was very different from those of poly(3HB-co-3HV) copolyesters having similar compositions produced from other microorganisms.

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Transformation and Mutation of Bacillus licheniformis 9945a Producing ${\gamma}-Poly(glutamic\;acid)$ (${\gamma}-Poly(glutamic\;acid)$ 생산성 균주 Bacillus licheniformis 9945a의 형질전환 미 돌연변이 유도)

  • Chung, Wan-Seok;Ko, Young-Hwan
    • Applied Biological Chemistry
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    • v.40 no.3
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    • pp.173-177
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    • 1997
  • Bacillus licheniformis 9945a releases a natural ${\gamma}-poly(glutamic\;acid)({\gamma}-PGA)$ into fermentation broth and shows a mucoid phenotype on the solid agar medium. Transformation of mucoid cells of Bacillus species has not been simple and straightforward. The transpositional activity of Tn10 in B. licheniformis also has not been own either. Thus, a spontaneous non-mucoid derivative of the B. licheniformis was obtained first. Shuttle vector pHV1248 containing mini-Tn10 was introduced into the non-mucoid derivative by the method of protoplast transformation. The resulting transformant was reverted to the wild mucoid phenotype, and then mutated randomly with the mini-transposon by heat induction. Auxotrophs requiring arginine, lysine, or tryptophan were isolated by replica plating method. Southern blotting and DNA-DNA hybridzation analysis showed that these auxotrophs were generated by mini-Tn10 insertion into the chromosomal DNA. This method of transformation and mutation using pHV1248 would be useful for the generation of diverse mutants of B. licheniformis 9945a.(Received January 24,1997; accepted March 10, 1997)

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Comparison of mechanical properties of all ceramic crown on zirconia blocks (지르코니아 블록 종류에 따른 전부도재관의 기계적 특성 비교)

  • Kim, Won-Young;Chung, In-Sung;Jeon, Byung-Wook
    • Journal of Technologic Dentistry
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    • v.37 no.3
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    • pp.107-113
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    • 2015
  • Purpose: This study provided the basic data for selecting the zirconia blocks by comparing the mechanical properties of the all ceramic crown between the domestic, import, translucent and shade blocks that were used in clinically. Methods: Currently, the most commercial block of five types(one import and two domestic block which is the translucent and shade) were used. It were elucidated by means of three point bending test, hardness test, FE-SEM observations and EDX analysis. The results were analyzed using a one-way ANOVA and Scheffe post hoc test for significant findings. Results: For flexural strength, LT specimen was the highest as 733.1 MPa, followed by JT specimen(712.0 MPa), ZT specimen(646.0 MPa), LS specimen(553.1 MPa), JS specimen(429.0 MPa). One-way ANOVA showed statistically significant difference between groups for flexural strength(p<0.05). For hardness, ZT specimen was the highest as 1556.5 Hv, followed by JT specimen(1540.3 Hv), LT specimen(1512.3 Hv), JS specimen(1472.0 Hv), LS specimen(1353.3 Hv). One-way ANOVA showed statistically significant difference between groups for hardness(p<0.05). Conclusion: Domestic block was higher than import block for flexural strength, and translucent block was higher than shade block for flexural strength. However, all blocks showed clinically acceptable range. There was no significant difference in hardness between domestic and import blocks. And significant difference was observed in translucent and shade blocks.

Comparison of Sesamoid Bone Position and Hallux Valgus Angle in Weight Bearing Conditions between Subjects with and without Hallux Valgus

  • Kim, Moon-Hwan;Jeon, In-Cheol;Hwang, Ui-Jae;Kim, Young
    • The Journal of Korean Physical Therapy
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    • v.28 no.6
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    • pp.381-384
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    • 2016
  • Purpose: Previous studies reported changes in the first metatarsophalangeal (MTP) joint angle in relation with and without weight bearing, but it is unclear whether sesamoid bone of the great toe changes in weight bearing conditions particularly in subjects with hallux valgus (HV). To investigate how weight bearing conditions can affect the position of the medial sesamoid bone (MSB), first MTP joint angle, and second intermetatarsal angle (IMA) in the recruited subjects. Methods: Subjects were recruited 24 with HV and 21 without HV in study. X-rays were taken in the weight bearing and non-weight bearing conditions. The distance of the MSB, first MTP joint angle, and second IMA were measured from the radiographs. Data were analyzed by paired and Independent t-test. The statistical significance level was p<0.05. Results: In both groups, the first MTP joint angles and the distance of the MSB were significantly smaller, while the second IMA was significantly greater in the weight bearing condition. The difference in the distance of the MSB between the two postures was significantly greater in the group with HV. Conclusion: Weight bearing can affect the first MTP joint angle, second IMA, and position of the MSB; the change in the position of the MSB in weight bearing was greater in the group with hallux valgus. The difference in these variables between weight bearing and non-weight bearing conditions may be considered when measuring HV.

Analysis of the transcripts encoding for antigenic proteins of bovine gammaherpesvirus 4

  • Romeo, Florencia;Spetter, Maximiliano J.;Moran, Pedro;Pereyra, Susana;Odeon, Anselmo;Perez, Sandra E.;Verna, Andrea E.
    • Journal of Veterinary Science
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    • v.21 no.1
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    • pp.5.1-5.12
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    • 2020
  • The major glycoproteins of bovine gammaherpesvirus 4 (BoHV-4) are gB, gH, gM, gL, and gp180 with gB, gH, and gp180 being the most glycosylated. These glycoproteins participate in cell binding while some act as neutralization targets. Glycosylation of these envelope proteins may be involved in virion protection against neutralization by antibodies. In infected cattle, BoHV-4 induces an immune response characterized by low neutralizing antibody levels or an absence of such antibodies. Therefore, virus seroneutralization in vitro cannot always be easily demonstrated. The aim of this study was to evaluate the neutralizing capacity of 2 Argentine BoHV-4 strains and to associate those findings with the gene expression profiles of the major envelope glycoproteins. Expression of genes coding for the envelope glycoproteins occurred earlier in cells infected with isolate 10/154 than in cells infected with strain 07/435, demonstrating a distinct difference between the strains. Differences in serological response can be attributed to differences in the expression of antigenic proteins or to post-translational modifications that mask neutralizing epitopes. Strain 07/435 induced significantly high titers of neutralizing antibodies in several animal species in addition to bovines. The most relevant serological differences were observed in adult animals. This is the first comprehensive analysis of the expression kinetics of genes coding for BoHV-4 glycoproteins in 2 Argentine strains (genotypes 1 and 2). The results further elucidate the BoHV-4 life cycle and may also help determine the genetic variability of the strains circulating in Argentina.

Substrate chain-length specificities of polyhydroxyalkanoate synthases PhaC1 and PhaC2 from Pseudomonas aeruginosa P-5 (Pseudomonas aeruginosa P-5에 존재하는 polyhydroxyalkanoate synthase PhaC1과 PhaC2의 기질특이성)

  • Woo, Sang Hee;Lee, Sun Hee;Rhee, Young Ha
    • Korean Journal of Microbiology
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    • v.52 no.4
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    • pp.455-462
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    • 2016
  • Pseudomonas aeruginosa P-5 is an unusual organism capable of synthesizing polyhydroxyalkanoates (PHAs) consisting of 3-hydroxyvalerate (3HV) and medium-chain-length (MCL) 3-hydroxyalkanoate (3HA) monomer units when C-odd alkanoic acids are fed as the sole carbon source. Evaluation of the substrate chain-length specificity of two P. aeruginosa P-5 PHA synthases ($PhaC1_{P-5}$ and $PhaC2_{P-5}$) by heterologous expression of $PhaC1_{P-5}$ and $PhaC2_{P-5}$ genes in Pseudomonas putida GPp104 revealed that $PhaC2_{P-5}$ incorporates both 3HV and MCL 3HAs into PHA, whereas $PhaC1_{P-5}$ favors only MCL 3HAs for polymerization. In order to obtain $PhaC2_{P-5}$ mutants with altered substrate specificity, site-specific mutagenesis for $PhaC2_{P-5}$ was conducted. Amino acid substitutions of $PhaC2_{P-5}$ at two positions (Ser326Thr and Gln482Lys) were very effective for synthesizing copolymers with a higher 3HV fraction. When recombinant P. putida GPp104 harboring double mutated $phaC2_{P-5}$ gene ($phaC2_{P-5}QKST$) was grown on nonanoic acid, 2.5-fold increase of copolymer content with 3.8-fold increase of 3HV fraction was observed. The $phaC2_{P-5}QKST$-containing Ralstonia eutropha PHB-4 supplemented with valeric acid also produced copolymers consisting of 3HV and 3-hydroxyheptanoate with a high 3HV fraction. These results suggest that recombinants containing $phaC2_{P-5}QKST$ could be useful for production of new PHA copolymers with improved material properties.