• Title/Summary/Keyword: Yi Ko

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Spatial Distribution and Improvement of Water Quality in the Youngrang Lake (영랑호 수질의 공간적 분포 및 개선방안)

  • Huh, In-Ryang;Yi, Geon-Ho;Jeong, Won-Gu;Kwon, Jae-Hyouk
    • Journal of Korean Society on Water Environment
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    • v.33 no.3
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    • pp.341-347
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    • 2017
  • From 2014 to 2016 water quality survey results according to the location and depth of Youngrang Lake are as follows: Distribution of dissolved oxygen in the water depth was investigated by the middle section and the downstream 1st, 3rd, 5th, when investigating bottem 1m interval anoxic layer. In organic matter and nutrient concentration distribution COD upstream 2.8 mg/L, middle section 4.2 mg/L downstream 4.1 mg/L, more than two times higher in bottem layer and TP concentrations showed a similar trend with COD, upstream of 0.047 mg/L, middle section was 0.051 mg/L, downstream of 0.059 mg/L. There was a difference in salinity every survey period the average salinity is lowest with 28.5‰ when the second survey. And the highest with 32.1‰ in the fourth investigation. Korean trophic state index($TSI_{KO}$) were showed eutrophic conditions in the middle section and downstream else showed mesotrophic state in the entire period. In order to evaluate the cause of water pollution Youngrang lake, regression analysis of the relationship between salinity and DO, COD, TN, TP, Chl-a results, $R^2$ is from 0.63 to 0.95 Youngrang lake water quality was found to have a close relationship with salinity due to inflow of seawater. As a result, in order to improve the quality of Youngrang lake efficient incorporation of the amount of water through the seawater influent as it is considered the key.

Power Generation Efficiency Model for Performance Monitoring of Combined Heat and Power Plant (열병합발전의 성능 모니터링을 위한 발전효율 모델)

  • Ko, Sung Guen;Ko, Hong Cheol;Yi, Jun Seok
    • Plant Journal
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    • v.16 no.4
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    • pp.26-32
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    • 2020
  • The performance monitoring system in the power plant should have the capability to estimate power generation efficiency accurately. Several power generation efficiency models have been proposed for the combined heat and power (CHP) plant which produces both electricity and process steam(or heating energy, hereinafter expressed by process steam only). However, most of the models are not sufficiently accurate due to the wrong evaluation of the process steam value. The study suggests Electricity Conversion Efficiency (ECE) model with determination of the heat rate of process steam using operational data. The suggested method is applied to the design data and the resulted trajectory curve of power generation efficiency meets the data closely with R2 99.91%. This result confirms that ECE model with determination of the model coefficient using the operational data estimate the efficiency so accurately that can be used for performance monitoring of CHP plant.

Ginsenoside Rg5 promotes wound healing in diabetes by reducing the negative regulation of SLC7A11 on the efferocytosis of dendritic cells

  • Wei Xia;Zongdong Zhu;Song Xiang;Yi Yang
    • Journal of Ginseng Research
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    • v.47 no.6
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    • pp.784-794
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    • 2023
  • Background: ginsenoside Rg5 is a rare ginsenoside with known hypoglycemic effects in diabetic mice. This study aimed to explore the effects of ginsenoside Rg5 on skin wound-healing in the Leprdb/db mutant (db/db) mice (C57BL/KsJ background) model and the underlying mechanisms. Methods: Seven-week-old male C57BL/6J, SLC7A11-knockout (KO), the littermate wild-type (WT), and db/db mice were used for in vivo and ex vivo studies. Results: Ginsenoside Rg5 provided through oral gavage in db/db mice significantly alleviated the abundance of apoptotic cells in the wound areas and facilitated skin wound healing. 50 μM ginsenoside Rg5 treatment nearly doubled the efferocytotic capability of bone marrow-derived dendritic cells (BMDCs) from db/db mice. It also reduced NF-κB p65 and SLC7A11 expression in the wounded areas of db/db mice dose-dependently. Ginsenoside Rg5 physically interacted with SLC7A11 and suppressed the cystine uptake and glutamate secretion of BMDCs from db/db and SLC7A11-WT mice but not in BMDCs from SLC7A11-KO mice. In BMDCs and conventional type 1 dendritic cells (cDC1s), ginsenoside Rg5 reduced their glycose storage and enhanced anaerobic glycolysis. Glycogen phosphorylase inhibitor CP-91149 almost abolished the effect of ginsenoside Rg5 on promoting efferocytosis. Conclusion: ginsenoside Rg5 can suppress the expression of SLC7A11 and inhibit its activity via physical binding. These effects collectively alleviate the negative regulations of SLC7A11 on anaerobic glycolysis, which fuels the efferocytosis of dendritic cells. Therefore, ginsenoside Rg5 has a potential adjuvant therapeutic reagent to support patients with wound-healing problems, such as diabetic foot ulcers.

Factors Influencing Nursing Students' Performance of Infection Control (간호학생의 의료관련감염예방 수행도에 영향을 미치는 요인)

  • Choi, Jong-Rim;Ko, Il-Sun;Yim, Yeong-Yi
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.23 no.2
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    • pp.136-148
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    • 2016
  • Purpose: This study was done to investigate the level of nursing students' awareness, attitude, safety climate, and performance of infection control, and to identify factors influencing performance. Methods: The sample consisted of 239 nursing students from 5 nursing schools. Data were collected from November 15 to December 11, 2013 and analyzed by frequency, t-test, ANOVA, Pearson correlation coefficients, and multiple stepwise regression with SPSS/WIN 21.0. Results: Of the participants, 216 (90.4%) had experienced contact with infectious diseases. The performance of personal hygiene was scored the highest followed by standard precautions, transmission precautions, and vaccination. There were significant correlations between awareness, attitude, safety-climate and performance. Awareness, safety-climate, attitude, contents of infection control education, and direct exposure to infectious disease collectively explained 30% of the variance in performance, and awareness was the most influential factor. Conclusion: The results indicate that performance of infection control by nursing students can be increased if awareness, safety climate, attitude, and contents of infection control education are improved, and exposure to infectious disease is decreased. These findings can be utilized to improve performance by developing education programs for infection control.

Activity of Deoxygenation Reaction on Ni/MgO-$Al_2O_3$ : Effect of Calcination Temperature (소성온도에 따른 Ni/MgO-$Al_2O_3$ 촉매의 탈산소 반응 활성)

  • Eum, Ic-Hwan;Jeong, Dae-Woon;Kim, Ki-Sun;Roh, Hyun-Seog;Yi, Bo Eun;Na, Jeong-Geol;Ko, Chang Hyun
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.243.2-243.2
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    • 2010
  • 현재 바이오디젤(Bio diesel)은 유지와 메탄올을 염기촉매를 넣고 전이에스테르화(Trans-esterification)반응하여 생산한다. 생산된 1세대 바이오 디젤은 분자 내 산소가 다량 함유되어 여러 가지 단점을 가지기 때문에 전이에스테르화 반응을 대체한 탈산소(Deoxygenation)반응이 주목 받고 있다. 본 연구에서는 유리지방산(Free fatty acid, FFA)인 올레익 산(Oleic acid)의 탈산소반응을 수행하였다. 하이드로탈사이트(Hydrotalcites) 구조인 MgO-$Al_2O_3$(MgO=70 wt%)를 6시간 동안 $500^{\circ}C$에서 예비소성(Pre-calcination)하여 담체로 사용하였다. 제조된 MgO-$Al_2O_3$ 담체에 함침법(Incipient wetness method)으로 20 wt% Ni을 담지 시켰다. 제조된 Ni/MgO-$Al_2O_3$촉매는 소성온도를 변화시켜 반응 실험을 수행하였다. TPR 분석을 통해 산화-환원특성을 분석하였고 생성물의 원소분석을 통해 생성물의 산소함량을 측정하였다.

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Conformational Change of Escherichia coli Signal Recognition Particle Ffh Is Affected by the Functionality of Signal Peptides of Ribose-Binding Protein

  • Ahn, Taeho;Ko, Ju Hee;Cho, Eun Yi;Yun, Chul-Ho
    • Molecules and Cells
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    • v.27 no.6
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    • pp.681-687
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    • 2009
  • We examined the effects of synthetic signal peptides, wild-type (WT) and export-defective mutant (MT) of ribose-binding protein, on the conformational changes of signal recognition particle 54 homologue (Ffh) in Escherichia coli. Upon interaction of Ffh with WT peptide, the intrinsic Tyr fluorescence, the transition temperature of thermal unfolding, and the GTPase activity of Ffh decreased in a peptide concentration-dependent manner, while the emission intensity of 8-anilinonaphthalene-1-sulfonic acid increased. In contrast, the secondary structure of the protein was not affected. Additionally, polarization of fluorescein-labeled WT increased upon association with Ffh. These results suggest that WT peptide induces the unfolded states of Ffh. The WT-mediated conformational change of Ffh was also revealed to be important in the interaction between SecA and Ffh. However, MT had marginal effect on these conformational changes suggesting that the in vivo functionality of signal peptide is important in the interaction with Ffh and concomitant structural change of the protein.

A Hybrid Navigation System for Intelligent Wheelchair (지능형 휠체어를 위한 하이브리드 내비게이션 시스템)

  • Ko, Eun-Jeong;Ju, Jin-Sun;Kim, Eun-Yi
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.552-557
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    • 2009
  • In this paper, we propose hybrid navigation system, for obstacle detection and avoidance in Intelligent wheelchairs (IWs). To robustly detect obstacles and avoid them on various environments, hybrid navigation system combines both range-sensor and camera information. For this, 10 range-sensors (2 ultrasonic and 8 infra-red sensors) and CCD camera are used. Through processing the informations obtained from those sensors, our system can detect obstacles with various sizes and shapes, and then avoid them. To assess the effectiveness of the proposed hybrid navigation system, it was tested on complex environments including various obstacles, then the results showed the potential of our system as mobility aids for disabled people.

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Optimization of in vitro seed germination of Taraxacum platycarpum

  • Lee, Jung-Hwan;Kim, Young-Kwan;Oh, Eun-Yi;Jung, Kuk-Young;Ko, Ki-Sung
    • Korean Journal of Environmental Agriculture
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    • v.28 no.4
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    • pp.403-408
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    • 2009
  • Dandelion (Taraxacum platycarpum) has been widely utilized for medicinal purposes. However, the dandelion seeds are relatively difficult to germinate under cultivation conditions, which hampers seedling propagation of dandelion plants and reduces the opportunity of usage of such a useful medicinal plant. Thus, in this study, in vitro conditions for the dandelion seed germination were optimized to enhance the germination rate. In seed washing steps, the sequential treatments with 20% of ethanol, 20% of NaOCl, and distilled water avoided microbial contamination with the highest in vitro germination rate (67.5%) from seeds sown in germination media. The media supplemented with 1.4 g/L of MS salts and 1% of sucrose significantly enhanced the germination rate compared to the media with 4.4 g/L of MS and 3% of sucrose. Sowing the seeds vertically in the optimized media supplement conditions, 1.4 g/L of MS salts and 1% of sucrose, gave the maximum in vitro germination rate (61%), which was almost three times higher than sowing seeds on a soil pot (23%). Our results indicate that the seed washing and sowing methods including germination medium supplements can be optimized to enhance in vitro seed germination of dandelion.

A Giant Unruptured Aneurysm of Middle Cerebral Artery Bifurcation Solely Presenting with Seizure - A Case Report - (경련만으로 발현된 중대뇌동맥 분지부의 미파열성 거대 동맥류 - 증례보고 -)

  • Kim, Jae Hoon;Yi, Hyeong Joong;Kim, Kwang Myung;Kim, Jae Min;Kim, Young Soo;Ko, Yong;Oh, Seong Hoon;Oh, Suck Jun
    • Journal of Korean Neurosurgical Society
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    • v.30 no.5
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    • pp.657-661
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    • 2001
  • Intracranial giant aneurysms have been known to cause clinical signs and symptoms, either by rupture, compression of surrounding structures, repeated minor leakage, or cerebral ischemia due to thromboembolism. A giant aneurysm which manifests only a seizure disorder comprises relatively few contributions. The authors present a case of a giant, unruptured aneurysm solely presenting with generalized tonic-clonic type seizure in a 43-year-old man. Brain computed tomogram(CT) and 3-D CT angiogram demonstrated a huge calcified aneurysm at the bifurcation of right middle cerebral artery. Complete neck clipping and aneurysmectomy followed by uneventful neurologic recovery.

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A Study on Metamorphosed-Genetic Algorithms by Applying the Meiosis for the Chromosome (염색체의 감수분열을 응용한 변형 유전알고리즘에 대한 연구)

  • Lee, Deog-Kyoo;Ko, Soung-Jun;Yi, Seok-Joo;Kim, You-Nam;Kim, Hag-Bae
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.6
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    • pp.1844-1851
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    • 2000
  • In this paper, a metamorphosed genetic algorithm based on the meiosis for human's chromosome is presented. In the algorithm, chromosomes in an individual are divided in half and in the other are divided into other rate. By our definition, they are composed of gametes with X-type chromosomes or Y-type chromosomes or especially M(mutation)-type chromosomes. When tow gametes among them are randomly selected and recombined, the new individual is correspondingly generated. Without reducing the searching space significantly, the global solution can be readily searched by new generated individual. The performance of he presented algorithm is examined and evaluated through proper simulation using test functions.

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