• Title/Summary/Keyword: Choi Chang Hak

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A Study on System Retrofit of Complex Energy System (복합에너지시스템의 성능개선에 관한 연구)

  • Choi, Jung-Hun;Moon, Chae-Joo;Chang, Young-Hak
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.1
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    • pp.61-68
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    • 2021
  • The application of renewable energies such as wind and solar has become an inevitable choice for many countries in order to achieve the reduction of greenhouse gases and healthy economic development. However, due to the intermittent characteristics of renewable energy, the issue with integrating a larger proportion of renewable energy into the grid becomes more prominent. A complex energy system, usually consists of two or more renewable energy sources used together to provide increased system efficiency as well as greater balance in energy supply. Compared with the power system, control and optimization of the complex energy system become more difficult in terms of modeling, operation, and planning. The main purpose of the complex energy system retrofit for samado island with microgrid system is to coordinate the operation with various distributed energy resources, energy storage systems, and power grids to ensure its reliability, while reducing the operating costs and achieving the optimal economic benefits. This paper suggests the improved complex energy system of samado island with optimal microgrid system. The results of test operation show about 12% lower SOC variation band of ESS, elimination of operation limit in PV and reduction of operation time in diesel generator.

Effect of Korean Medicine Treatment on Vancomycin-resistant Enterococci Colonization in a Stroke Patient: A Case Report (반코마이신 내성 장알균(Vancomycin Resistant Enterococci)이 검출된 뇌졸중 환자의 집락 해제에 대한 한방치료 1례 : 증례보고)

  • Seo, Hyung-bum;Lee, Chan;Cho, Im-hak;Heo, Gi-yoon;Kang, Hee-kyung;Han, Chang-woo;Kim, So-yeon;Choi, Jun-yong;Park, Seong-ha;Yun, Young-ju;Hong, Jin-woo;Kwon, Jung-nam;Lee, In
    • The Journal of Internal Korean Medicine
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    • v.41 no.6
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    • pp.1191-1199
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    • 2020
  • We studied the effect of Korean medicine treatment on the clearance of vancomycin-resistant enterococcus (VRE) colonization and on improvement in symptoms in a stroke patient. The patient was continuously followed up with stool VRE cultures while being treated with herbal medicine, Chunglijagam-tang, acupuncture, and oxygen therapy. We also checked the coccygeal pressure sore condition and the oxygen levels during therapy. No VRE colonization was found after treatment and the oxygen levels and pressure sores had improved. This study proved that Korean medicine treatment could be effective for the clearance of VRE colonization and improvement of symptoms.

Forest Stand Structure and Interspecific Association in the Habitats of Allium victorialis var. platyphyllum (산마늘 자생지의 임분구조와 식물종의 연관)

  • Kim, Hye-Jin;Yun, Chung-Weon;Doh, Eun-Soo;Chang, Jun-Pok;Choi, Myung-Suk;Yang, Jae-Kyung;Park, Hee-Kwon;Shin, Hak-Sub;Lee, Seo-Hui;Bae, Kwan-Ho;Cho, Hyun-Je
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.565-576
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    • 2011
  • This study was conducted to describe forest stand characteristics of the habitats of Allium victorialis var. platyphyllum population from the ecological analysis of classification of vegetation types, importance values, species diversity, interspecific association and community similarity in Ulleung Island and Mt. Hambaek, in which investigated by 48 plots ($10m{\times}10m$). The vegetation studied was classified into 1 community group, 2 communities, 2 groups and 3 subgroups for a species unit and divided by 5 units for a vegetation unit. In the Fagus engleriana group (vegetation unit 1, 2 and 3), importance value of A. victorialis var. platyphyllum in herb layer showed relatively higher value than other units. Importance value of A. victorialis var. platyphyllum in herb layer had higher value. In the analysis of interspecific association, most of the species associated positively to A. victorialis var. platyphyllum belonged to habitat features of valley area and sub-alpine zone. Therefore, it was considered that the growing environment of A. victorialis var. platyphyllum population was closely correlated to soil moisture and air humidity.

Oral Administration of Weissella confusa WIKIM51 Reduces Body Fat Mass by Modulating Lipid Biosynthesis and Energy Expenditure in Diet-Induced Obese Mice (생쥐 비만모델에서 Weissella confusa WIKIM51 식이에 따른 지방합성 및 에너지 대사 조절로 인한 체지방 감소 효과)

  • Lim, Seul Ki;Lee, Jieun;Park, Sung Soo;Kim, Sun Yong;Park, Sang Min;Mok, Ji Ye;Chang, Hyunah;Choi, Hak-Jong
    • Microbiology and Biotechnology Letters
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    • v.50 no.1
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    • pp.135-146
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    • 2022
  • Obesity is closely associated with profound dyslipidemia, insulin resistance, and fatty liver disease. Recent reports have suggested that alterations in gut microbiota can be linked to diet-induced obesity. In this study, the anti-obesity effects of Weissella confusa WIKIM51 isolated from kimchi were investigated, as evidenced by: i) reduced lipid accumulation and downregulated adipogenesis-related genes in 3T3-L1 adipocytes; ii) suppressed gains in body weight and epididymal fat mass; iii) reduced serum lipid levels, for example, triglyceride and total cholesterol; iv) increased serum adiponectin levels and reduced serum leptin levels; v) downregulated lipogenesis and upregulated β-oxidation-related genes in the epididymal fat; and vi) altered microbial communities. The collective evidence indicate the potential value of W. confusa WIKIM51 as a functional food supplement for the prevention and amelioration of obesity.

A Case Report of Korean Medicine Treatment of a Lung Cancer Patient with Chemotherapy-induced Peripheral Neuropathy (편평상피세포 폐암 환자의 항암화학요법에 의해 유발된 말초신경병증에 대한 한방치험 1례)

  • Kim, Kyun Ha;Kim, Min-hwa;Heo, Gi-yoon;Lee, Chan;Cho, Im-hak;Kang, Hee-kyung;Kim, So-yeon;Park, Seong-ha;Yun, Young-ju;Lee, In;Han, Chang-woo;Hong, Jin-woo;Kwon, Jung-nam;Choi, Jun-Yong
    • The Journal of Internal Korean Medicine
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    • v.42 no.6
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    • pp.1341-1348
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    • 2021
  • The purpose of this study is to report the effect of Korean medicine on a squamous cell lung cancer patient with chemotherapy induction peripheral neuropathy (CIPN). A 61-year old male patient, who had received 4 cycles of chemotherapy after lung surgery from squamous cell lung cancer, was treated with acupuncture and herbal medicines, including Uchasingi-hwan and Samchilchoongcho-capsule, to control CIPN and dyspnea on exertion. The degree of pain was assessed by a numeric rating scale (NRS). After receiving acupuncture and herbal medicines, the NRS score for CIPN symptoms was reduced from 4 to 1 and the NRS score for dyspnea on exertion decreased from 3 to less than 1. Korean medicine could therefore be useful in reducing peripheral neuropathy occurring after chemotherapy and dyspnea after lobectomy.

Hepatic/Renal Safety Evaluation of Cheongsimyeonja-tang (Qīngxīn Liánzǎo Tāng), Dodam-tang (Táodàn Tāng), Hyeolbuchukso-tang (Xuè Fǔ Zhú Yū Tāng), and Boshiniknai-tang (Bǔ Shèn Yì Nǎo Tāng) for Cerebrovascular Diseases : A Retrospective Study (뇌혈관질환 환자에 대한 청심연자탕(淸心連子湯), 도담탕(導痰湯), 혈부축어탕(血府逐瘀湯), 보신익뇌탕(補腎益腦湯)의 간기능과 신기능 안전성 평가 : 후향적 연구)

  • Min-hwa Kim;Im-hak Cho;I-rang Nam;Maria Kim;Ki-beom Ku;Se-yeon Lee;Jung-nam Kwon;In Lee;Jin-woo Hong;Young-ju Yun;So-yeon Kim;Chang-woo Han;So-jung Park;Jun-yong Choi;Hyeun-kyoo Shin
    • The Journal of Internal Korean Medicine
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    • v.44 no.3
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    • pp.439-454
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    • 2023
  • Objectives: As Korea transitions into an aging society, the incidence of cerebrovascular disease is expected to increase. Herbal medicine is commonly used in Oriental medicine to treat cerebrovascular disease. However, there is insufficient clinical evidence to actively support the safety of herbal medicine in clinical practice. Therefore, the aim of this study was to determine the toxicity and safety of four herbal medicines (Cheongsimyeonja-tang, Dodam-tang, Hyeolbuchukso-tang, and Boshiniknai-tang) in patients with cerebrovascular disease. Methods: This study used electronic medical records to analyze patients admitted to an oriental medicine hospital from April 1, 2017, to December 31, 2020. Liver and renal function values at the time of admission and discharge were compared. Results: A total of 25 patients were included in this study. We found no significant differences in various variables, such as complete blood count, liver-renal function test, and urine, before and after the administration of the four herbal medicines. Additionally, no significant adverse events related to herbal medicine were observed. Conclusions: This study confirmed the safety of the four herbal medicines in patients with cerebrovascular disease who were hospitalized in a single Oriental medicine hospital.

Added Value of Chemical Exchange-Dependent Saturation Transfer MRI for the Diagnosis of Dementia

  • Jang-Hoon Oh;Bo Guem Choi;Hak Young Rhee;Jin San Lee;Kyung Mi Lee;Soonchan Park;Ah Rang Cho;Chang-Woo Ryu;Key Chung Park;Eui Jong Kim;Geon-Ho Jahng
    • Korean Journal of Radiology
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    • v.22 no.5
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    • pp.770-781
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    • 2021
  • Objective: Chemical exchange-dependent saturation transfer (CEST) MRI is sensitive for detecting solid-like proteins and may detect changes in the levels of mobile proteins and peptides in tissues. The objective of this study was to evaluate the characteristics of chemical exchange proton pools using the CEST MRI technique in patients with dementia. Materials and Methods: Our institutional review board approved this cross-sectional prospective study and informed consent was obtained from all participants. This study included 41 subjects (19 with dementia and 22 without dementia). Complete CEST data of the brain were obtained using a three-dimensional gradient and spin-echo sequence to map CEST indices, such as amide, amine, hydroxyl, and magnetization transfer ratio asymmetry (MTRasym) values, using six-pool Lorentzian fitting. Statistical analyses of CEST indices were performed to evaluate group comparisons, their correlations with gray matter volume (GMV) and Mini-Mental State Examination (MMSE) scores, and receiver operating characteristic (ROC) curves. Results: Amine signals (0.029 for non-dementia, 0.046 for dementia, p = 0.011 at hippocampus) and MTRasym values at 3 ppm (0.748 for non-dementia, 1.138 for dementia, p = 0.022 at hippocampus), and 3.5 ppm (0.463 for non-dementia, 0.875 for dementia, p = 0.029 at hippocampus) were significantly higher in the dementia group than in the non-dementia group. Most CEST indices were not significantly correlated with GMV; however, except amide, most indices were significantly correlated with the MMSE scores. The classification power of most CEST indices was lower than that of GMV but adding one of the CEST indices in GMV improved the classification between the subject groups. The largest improvement was seen in the MTRasym values at 2 ppm in the anterior cingulate (area under the ROC curve = 0.981), with a sensitivity of 100 and a specificity of 90.91. Conclusion: CEST MRI potentially allows noninvasive image alterations in the Alzheimer's disease brain without injecting isotopes for monitoring different disease states and may provide a new imaging biomarker in the future.

Evaluation of Effective Dose in Dental Radiography (치과 방사선 검사에서 유효선량 평가)

  • Han, Su-Chul;Lee, Bo-Ram;Shin, Gwi-Soon;Choi, Jong-Hak;Park, Hyok;Park, Chang-Seo;Chang, Kye-Yong;Kim, Bo-Ram;Kim, You-Hyun
    • Journal of radiological science and technology
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    • v.34 no.1
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    • pp.27-33
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    • 2011
  • Along with the developments of science technology, up-to-date medical radiation equipments are introduced. Those equipments has brought many progresses in diagnosing patients not only in the quantitative aspects but in the qualitative ones. Especially, in the case of dental radiography, patients can be exposed more than CT, cone beam computed tomography (CBCT). In this study, we used human phantom and TLD-100H to measure the organ dose in each dental radiography and computed the effective dose according to ICRP (International Committee for Radioactivity Prevention) 60, 103. We measured the effective dose to be 5.1 and $29.5{\mu}Sv$ in the panoramic radiography and 11.2 and $14.4{\mu}Sv$ in the cephalometric radiography respectively. We also executed the CBCT and CT test on the maxillaries and the mandibles and found the amounts of effective dose were 53.7, 209.6, 129, and $391.5{\mu}Sv$ respectively in the CBCT and $93.3{\mu}$, 139.5, 282.7 and $489.7{\mu}Sv$ in the CT test. Consequently, it was shown that the effective dose in the CBCT test was lower than one in the CT test, but was higher in both panoramic and cephalometric radiography.

A Series of Biographies of The Collectors of Modern Archaic Art Objects of Korea 1: Jang, Taek Sang (한국 근대의 고미술품 수장가 1: 장택상)

  • Kim, Sang-yop
    • (The)Study of the Eastern Classic
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    • no.34
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    • pp.415-447
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    • 2009
  • It is encouraging fact that people are more interested in collecting modern archaic art objects of Korea with broadening spectrum of research these days. For the research in this area is significant in that it makes us learn the level of collection and appreciation which were prevalent at the end of the Josen Age by trend of preferring Occidental pictures as well as modern change in the form of collection, and enables us to reconstruct the history of modern art objects in East Asia. Except Jeon, Hyung-Pil(全鎣弼: 1906-1962), the modern collectors of Korea were not studied in details with respect to the course or contents of collection. Besides Jeon, Hyung Pil, the main modern collectors of Korea were Park, Young-cheol(朴榮喆: 1879-1939), Kim, Yong-jin(金容鎭: 1882-1968), Ham, Seok-tae(咸錫泰: 1889-?), Kim, Sung-soo(金性洙: 1891-1955), Choi, Chang-hak(崔昌學: 1891-?), Jang, Taek-sang(張澤相: 1893-1969), Kim, Chan-young(金瓚泳: 1893-?), Lee, Han-bok(李漢福: 1897-1940), Park, Chang-hun(朴昌薰: 1898-1951), Baek, In-je(白麟濟: 1898-?), Lee, Byung-jik(李秉直: -1973), et al. The object of this publication in serial form is to trace and identify the life, collected articles and contents of collection of Korean collectors who intensively collected archaic art objects in the modern age of Korea, especially, under the rule of Japanese imperialism. The first person to be introduced in this publication in serial form is Jang, Taek Sang, a leading figure in the political history of Korea. Born as the son of wealthy man, he ascended to the position of prime minister, leading a dramatic life. Being a distinguished orator, Jang, Taek Sang was well known as an appreciator and collector of picture, calligraphy and pottery. As one of the collectors of main cultural property under the rule of Japanese imperialism, Jang, Taek Sang collected countless distinguished heritages, most of which were lost during the Korean War. As he became a candidate for president to compete with Lee, Seung Man later, he sold main heritages. Thus, nearly all of the collected articles were scattered.

Status and Change in Chemical Properties of Polytunnel Soil in Korea from 2000 to 2012

  • Kang, Seong Soo;Roh, Ahn Sung;Choi, Seung Chul;Kim, Young Sang;Kim, Hyun Ju;Choi, Moon Tae;Ahn, Byoung Gu;Kim, Hee Kwon;Park, Sang Jo;Lee, Young Han;Yang, Sang Ho;Ryu, Jong Soo;Sohn, Yeon Gyu;Kim, Myeong Sook;Kong, Myung Suk;Lee, Chang Hoon;Lee, Deog Bae;Kim, Yoo Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.641-646
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    • 2013
  • Chemical properties of agricultural soils in Korea have been investigated at four-year interval in order of paddy, polytunnel, upland, and orchard soils since 1999; polytunnel soils were investigated over the whole country in 2000, 2004, 2008, and 2012. Polytunnel soils were taken from the surface (0-15 cm) and subsurface (15-30 cm) at 2,651, 1,274, 1,374 and 1,374 sites in all provinces of South Korea. One hundred sampling sites located in more than 400 m altitude were additionally investigated in 2008 and 2012. Average of soil chemical properties in 2012 except Jeju province were 6.6 for pH, 3.2 dS $m^{-1}$ for EC, 37 g $kg^{-1}$ for organic matter (OM), 1,049 mg $kg^{-1}$ for available (Avail.) phosphate, 1.58 $cmol_c\;kg^{-1}$ for exchangeable (Exch.) K, 10.6 $cmol_c\;kg^{-1}$ for Exch. Ca, and 3.3 $cmol_c\;kg^{-1}$ for Exch. Mg. Except pH, averages of all chemical properties exceeded the upper limit of optimal range. The median values except pH showed a lower value than the averages. The pH, OM and Exch. Ca had slightly increased from 6.3 to 6.6, from 34 to 37 g $kg^{-1}$, and from 7.7 in 2000 to 10.6 $cmol_c\;kg^{-1}$ in 2012, respectively. The order of sample ratios exceeding the optimal range were Avail. $P_2O_5$ (83%) > Exch. Ca (80%) > Exch. K (70%) > Exch. Mg (65%) > EC (55%) > OM (48%) > pH (29%) in 2012. The order of sample ratios below the optimal range was OM (25%) > Exch. K (25%) > pH (20%), Exch. Mg and Avail. $P_2O_5$ (9%) > Exch. Ca (6%) in 2012. The excessive proportion of pH, Exch. Ca, Exch. Mg and OM slightly increased, while the insufficient proportion of those decreased. Approximately 55% of polytunnel soils exceeding EC 2 dS $m^{-1}$ was evaluated with salt accumulated soils having the risk of growth disorder of crops. Nutrient contents in polytunnel soils in Korea showed high level especially Avail. $P_2O_5$ and Exch. cations. Therefore, recommended fertilization based on soil testing or plant testing is needed for soil nutrient management.