• Title/Summary/Keyword: 관찰 선택 효과

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Effect of Chemical Treatments on Seed Germination of Saururus chinensis (Lour.) Baill., an Endangered Species in Korea (멸종위기 야생식물 삼백초의 종자발아에 미치는 화학적 처리의 영향)

  • Cho, Ju Sung;Lee, Cheol Hee
    • Korean Journal of Plant Resources
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    • v.29 no.4
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    • pp.385-392
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    • 2016
  • This research was performed to develop seminal propagation method of Saururus chinensis (Lour.) Baill. by conducting a rigorous germination study. Well-selected seeds were dry-stored at 4 ± 1.0℃ during the experiment. To study dormancy type, non-stored seeds were analyzed by embryo observation, germination test and detecting for any difficulties in seed coat to absorb moisture. Then to improve germination, seeds were submerged for 24 hours in a solution of varying concentrations containing one of plant growth regulators and minerals. According to research, fleshly matured seeds had an undifferentiated embryo and had a low germination rate below 5%. In addition, water submersion led to moisture absorption, embryo in the seeds grew and germinated so it was deemed morphophysiological dormant seeds. Percent germination (PG) and germination energy (GE) was greatly improved by soaking in plant growth regulators and minerals for 24 hours. Especially, 500 ㎎/L GA3 treatment resulted in the highest GE as 46.1%. KNO3 meaningfully improved PG (54.3∼57.7%) at 10∼20 mM but effect of minerals on germination acceleration as GE were negatively impacted in all concentrations.

Comparison of Smart Phone Application Based Hearing Screening and Hearing Handicap Inventory (스마트 폰 애플리케이션 기반 청각선별과 설문 청각선별의 비교)

  • Heo, Seung-Deok;Park, Chan-Ho;Song, Byung-Seop
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.11 no.1
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    • pp.73-79
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    • 2017
  • It is difficult to detect the adult hearing loss after the language acquisition because of its slow progression, which can be evaluated voluntarily and actively when the appropriate tools are provided. Smartphones are one of useful tools, and they can utilize surveys and/or applications for hearing screening. This study aims to verify the possibility as a tool discovering delayed acquired hearing losses by comparing the pure tone screening application (app_PTS) which was recently developed by our research team and hearing handciap inventory (HHI). The subjects were 22 people whose age ranges from 10s to 80s. For pure tone averages (PTAs), hearing threshold level was selected the best one in same frequency, in both ears. Sensitivity and specificity of HHI were confirmed based on self awareness of hearing loss and PTAs at 1, 2, 4 kHz. Comparisons of two tests were measured by analyzing simple regression of correlation between PTAs of App_PTS and HHI scores. Sensitivity and specificity were 1.000 in both criteria. There was a statistically significant relationship between the PTAs_4 kHz and HHI (R-square = .951, p = .000). Hearing screening by questionnaire showed high correlation with smart phones based on application. Therefore, it can be useful as a hearing screening tool for individual life cycle using an user-friendly tool.

Usability Comparative Testing of Pointing Input Devices on a Small-Sized Mobile Computing Device - Focused on Trackpoint and Touchpad - (이동형 컴퓨팅 기기에서의 포인팅 입력 장치의 사용성 비교연구 - 트랙포인터와 터치패드를 중심으로 -)

  • Jeong, Seong-Won;Lee, Kun-Pyo
    • Archives of design research
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    • v.18 no.4 s.62
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    • pp.175-184
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    • 2005
  • PDA(Personal Digital Assistants) and laptop computer that are small sized mobile implements are typical devices which capable of using wireless internet. They seem to have a tendency to possess multi-function as well as to miniaturize in accordance with taking advantage of today's digital convergence circumstance. It should be considered that the pointing input device of these mobile computer that have PDA size and laptop's performance has to be added to something very small instead of 4-button, 5-button navigator and with the electric pen. The basic framework for this study is to investigate the usability of the two input devices Trackpoint and Touchpad which regarded as a alternative pointing device for small sized mobile computer. 14 novice subjects compared a Trackpoint to a Touchpad across five curser-control tasks. The study found that subjects executed not more slowly with a Trackpoint input device than with the Touchpad. Observation shows that learning for Trackpoint appears to have had more than for the Touchpad. Subjects expressed preference for the Trackpoint in general work.

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Investigation of Gas Transport Properties of Polymeric Membranes having Different Chain Lengths Via Molecular Dynamics (MD) (분자동역학을 이용한 고분자 주쇄의 길이 변화에 따른 기체 투과 성능 연구)

  • Kang, Hoseong;Park, Chi Hoon
    • Membrane Journal
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    • v.28 no.1
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    • pp.67-74
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    • 2018
  • In the molecular dynamics study of polymeric membranes, it is very important to select the proper length of the polymer main chain because it requires a large number of constituent atoms and a long time to simulate the permeation behavior. In this study, we tried to investigate how the correlation between polymer main chain length and permeation behavior appears in actual molecular dynamics simulation results. Molecular dynamics were performed using the widely known commercial polymer Kapton(R) polyimide structure and the gas permeation behavior was simulated. The movement of the polymer main chain was not related to its length and the short main chain length did not act more actively. In addition, unlike the prediction that the end group of the polymer main chain is relatively easy to move, there are many cases where the atoms located at the middle of the polymer main chains have a higher movement than the atoms located at the end groups. Finally, permeabilities of the gas molecules was not affected by the length of the main chain and the end groups of the polymer, which indicates that the end effect should be carefully mentioned and followed by the verification process.

Characterization and Frequency of Vancomycin Resistance in Staphylococcus aureus Isolated in Korea (국내에서 분리된 포도상구균의 Vancomycin 내성빈도 및 특성)

  • 박성언;김종배
    • Biomedical Science Letters
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    • v.6 no.3
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    • pp.201-208
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    • 2000
  • The vancomycin, one of the family of glycopeptide antibiotics, inhibits the synthesis of bacterial cell wall peptidoglycan and has been widely used against gram-positive bacterial infections, especially for a treatment of methicillin resistant S. aureus infection. However, clinical isolate which was intermediately resistant to vancomycin (Mu50: MIC 8 $\mu\textrm{g}$/ml) was isolated in recent years. In this study we performed vancomycin susceptibility test with the increment method and population analysis with clinical isolates S. aureus. Also we did several kinds of tests with three selected isolates (s129: MIC 7 $\mu\textrm{g}$/ml, s134: MIC 7 $\mu\textrm{g}$/ml, s135: MIC 8 $\mu\textrm{g}$/ml) to find out possible mechanism of vancomycin resistance. As a result, the prevalence of vancomycin resistant S. aureus isolates among S. aureus strains resistant to methicillin was 23.3% (25/107). The vancomycin resistances of isolated strains of S. aureus were between those of Mu5O and Mu3 strains. By PCR analysis, none of the isolates with decreased vancomycin susceptibility contained known vancomycin resistant genes such as vanA, vanB, vanC1, vanC2, and vanH. Major bands of 81 kDa, 58 kDa, 33 kDa, 28 kDa were demonstrable in whole cell lysates by SDS-PAGE from all three isolates as well as reference strains. And especially,45 kDa protein was overproduced in Mu50 strains. Among them increased production of NAD$^{+}$-linked-$_{D}$-lactate dehydrogenase (dnLDH) were detected from one clinical strain (s135) and Mu5O strain. From these data, we suggest that the mechanism of vancomycin resistance in these isolates are distinct from that in enterococci.

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A Field Application Feasibility of Biologically Derived Substances (Naphthoquinone Derivate: NQ 2-0) for the Mitigation of Harmful Cyanobacterial Blooms (유해 남조류 제어를 위한 생물유래 살조물질 Naphthoquinone 유도체 (NQ 2-0)의 현장 적용 가능성)

  • Joo, Jae-Hyoung;Park, Chong-Sung;Choi, Hye Jeong;Lee, Heon Woo;Han, Myung-Soo
    • Ecology and Resilient Infrastructure
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    • v.4 no.3
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    • pp.130-141
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    • 2017
  • We evaluated the field application feasibility that biologically derived substances (Naphthoquinone derivate: NQ 2-0) can be used for the eco-friendly mitigation of natural harmful cyanobacterial blooms in freshwater. We conducted a 30 ton scale mesocosm experiment to investigate the effects of NQ 2-0 on biotic and abiotic factors in water collected from Gi-heung reservoir. In the mesocosm experiments, the abundance of Microcystis sp. was continuously increased in the control. However, the Microcystis sp. cell density was sharply decreased on the $10^{th}$ day. In the treatment, NQ 2-0 showed the strong and selective algicidal activity toward the target cyanobacteria (Microcystis sp.). Accordingly, the algicidal activity of NQ 2-0 compound increased gradually until $10^{th}$, $15^{th}$ days and algal biomass was decreased to 99.4 and 100 %, respectively. NQ 2-0 compound was not only selective algicidal activity but also the growth of other phytoplankton and increased the Shannon-Wiener diversity index of phytoplankton. In the mesocosm experiments, the dynamics of biotic (bacteria, heterotrophic nanoflagellate, ciliates, zooplankton) and abiotic (water temperature, dissolved oxygen, pH, conductivity, nutrients) factors remained unaffected. These results suggest that NQ 2-0 could be a selective and ecologically safe algicide to mitigate harmful cyanobacterial blooms. In addition, it is believed that NQ 2-0 will play a major role in forming a healthy aquatic ecosystem by facilitating habitat and food supply of aquatic organisms.

Effects of Fermented Milk with Hot Water Extract from Acanthopanax senticosus and Codonopsis lanceolata on the Immune Status of Mouse (가시오가피와 더덕 추출물을 첨가한 발효유가 마우스의 면역기능에 미치는 영향)

  • Lim, Sang-Dong;Seong, Ki-Seung;Kim, Kee-Sung;Han, Dong-Un
    • Korean Journal of Food Science and Technology
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    • v.39 no.3
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    • pp.323-329
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    • 2007
  • We investigated the immunomodulatory actions of water extract from Acanthopanax senticosus in male ICR mice. The mice were treated with fermented milk containing three added doses of freeze dried extract: 3 mg/kg (A), 9 mg/kg (B), and 27 mg/kg (C) of body weight with Acanthopanax senticosus: Codonopsis lanceolata (8:2) for 7 and 10 weeks, respectively. Organ weights, plaque-forming cell tests, agglutination tests, IgG tests, differential white cell counts, and histological tests were performed at the 7th and 10th weeks of dietary treatment. There were no significant differences in body weight and organ weight. The spleen indices of group B at 7 weeks and group C at 10 weeks were significantly higher than those of the control group (p<0.05). For the plaque-forming cell test, groups B and C at 7 weeks, and group C at 10 weeks, showed significant increases over the control group (p<0.05). The agglutination test decreased with an extended experimental period. Groups A, B, and C at 7 weeks, and groups B and C at 10 weeks, had greater antibody responses to sheep red blood cells (SRBC) than the control group. The IgG antibody production of group C at 7 weeks and groups B and C at 10 weeks were significantly higher than the control group (p<0.05). In groups B and C, lymphocyte percentage was higher than the control group, and their spleen and thymus tissues showed active immune reactions.

A Study on Determinants of the Number of Banking Relationships in Korea: Firm-specific Determinants and Effects of Business Cycle (우리나라 기업의 거래은행 수 결정요인에 관한 연구: 경기변동의 영향을 포함하여)

  • Hwang, Soo-Young;Lee, Jung-Jin
    • Management & Information Systems Review
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    • v.36 no.4
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    • pp.53-80
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    • 2017
  • The purpose of this study is to examine the determinants of the number of bank relationships in Korea. Firm-specific determinants considered here include leverage, size, age, return on asset, investment grade, tangibility, liquidity, R&D expenditure. We estimate the effects of these variables, and compare the results with those from previous studies performed for other economies. Concerning the effects of business cycle, we find that the business cycle is an important factor in determining the number of bank relationships. The number of bank relationships varies over the business cycle, and we notice a counter-cyclical behavior, which means the number decreases during economic expansions and increases during contractions. This result can be interpreted as a result of firms' diversification of borrowings into multiple banks in order to reduce the liquidity risk during the recession. In the subsets, however, the number of bank relationships for large firms is stable regardless of the business cycle. Unlisted firms, non-chaebol, and low credit quality firms which have relatively limited access to alternative sources of financing show counter-cyclical behavior. Finally, such phenomena is not observed in the non-competitive credit market, while they show a counter-cyclical behavior in the competitive credit market.

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Presurgical Nasoalverolar Molding in Fraternal Twins with Bilateral Cleft Lip and/or Palate: A Case Report (양측성 구순/구개열을 가진 이란성 쌍둥이를 대상으로 한 술전 비치조정형술: 증례보고)

  • Kim, Jinsun;Kim, Youngjin;Nam, Soonhyeun;Kim, Hyunjung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.41 no.1
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    • pp.72-79
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    • 2014
  • Cleft lip and palate(CLP) is one of the most common craniofacial deformities that requires systemic management involving a multidisciplinary team approach. Although there has been great improvement in the field of cleft surgery, surgical approach alone cannot resolve the various problems in treating cleft lip and palate. Hence the need for presurgical treatment was appreciated and especially, the concept of presurgical nasoalveolar molding was applied to treat unilateral and bilateral cleft lip and palate patients. Presurgical nasoalveolar molding(PNAM) of unilateral cleft mainly aims to recover nasal symmetry while the objectives of pre-surgical nasoalveolar molding in the bilateral cleft are to elongate the columella, to erect the tip of nose, and to reposition the forward displaced premaxillary region. This report covers the case of fraternal twins diagnosed with bilateral cleft. Retraction of the premaxillary region and nasoalveolar molding were conducted for 70 days until cheiloplasty, using elastic bands and nasoalveolar molding appliances. After cheiloplasty, there had been improvements in the length of columella and the position of forward-displaced premaxilla for both patients compared to their initial states. The esthetics was also satisfactory for both the surgery and the parents. In order to maximize the efficacy of the appliance, three components should be in balance; patients' adaptation to the appliance, parents' cooperation and proper selection and careful adjustment of the appliance by the dentist.

The Analysis of Risk Factors of Treatment Failure in MDR-TB (다제내성 폐결핵 치료실패의 위험인자 분석)

  • Kim, Hyoung-Soo;Choi, Kwang-Min
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.6
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    • pp.686-692
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    • 2001
  • Background : Outbreaks of multidrug-resistant tuberculosis(MDR-TB) are caused by the low rate of treatment response due to limitation in number of available drugs and high rates of adverse drug side-effects. This study analysed the risk factors for MDR-TB patients, who did not respond to treatment, with an aim to improve the rate of treatment response. Methods : Retrospective study of 111 MDR-TB patients at National Mokpo Tuberculosis Hospital from Jan. 1996 to Dec. 1998 was made. The patients were separated into two groups ; group I comprised of patients who were treated successfully and group II comprised of those were not treated successfully. In order to analyze the risk factors for treatment failure, differences between the two groups were compared and the confidence limit regarding the results were tested using an independent t-test. chi-square test and a Fisher's exact test. Results : The treatment failure rate of MDR-TB patients was 32% (36 patients), and treatment success rate 68%(75 patients). This study found no significant difference between two groups in terms of age, sex, family history, extent of the disease on the chest X-ray, the number of sensitive drugs in the treatment regimen, and the number of sensitive bactericidal drugs in the treatment regimen (p>0.05). However, a past history of pulmonary tuberculosis, cavitary lesions on the chest X-ray, the number of treatments, the number of resistant drugs and the number of drugs used showed a significant difference(p<0.05). Conclusion : The rate of treatment failure in MDR-TB was increased by a past history of pulmonary tuberculosis, cavitary lesions on the chest X-ray, the number of treatments, the number of resistant drugs and the number of drugs used. For improving the treatment response of MDR-TB, every effort should be made to reduce the drug resistance caused by failure of the first treatment.

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