• Title/Summary/Keyword: Gil-ho Kim

Search Result 1,797, Processing Time 0.039 seconds

고유진동수와 모드의 민감도를 계산하기 위한 대수적 방법 (Algebraic Method for Computation of Natural Frequency and Mode Shape Sensitivities)

  • 정길호;김동옥;이종원;이인원
    • 대한기계학회논문집A
    • /
    • 제21권5호
    • /
    • pp.707-718
    • /
    • 1997
  • This paper presents an efficient numerical method for the computation of eigenpair derivatives for a real symmetric eigenvalue problem with distinct and multiple eigenvalues. The method has a very simple algorithm and gives an exact solution. Furthermore, it saves computer sotrage and CPU time. The algorithm preserves not only the symmetricity but also the band width of the matrices, allowing efficient computer storage and solution techniques. Results from the proposed method for calculating the eigenpair derivatives are compared with those from Rudisill and Chu's method and Nelson's method which is known efficient one in the case of distinct natural frequencies. As an example to demonstrate the efficiency of the proposed method in the case of distinct eigenvalues, a cantilever plate is considered. The design parameter of the cantilever plate is its thickness. For the eigenvalue problem with multiple natural frequencies, the adjacent eigenvectors are used in the algebraic equation as side conditions, lying adjacent to the multiplicity of multiple natural frequency distinct eigenvalues, which appear when design parameter varies. A cantilever beam is used to demonstrate the efficiency of the proposed method in the case of multiple natural frequencies. Results form the proposed method for calculating the eigenpair derivatives are compared with those from Dailey's method(an amendation of Ojalvo's work) which finds the exact eigenvector derivatives. The design parameter of the cantilever beam is its height. Data is presented showing the amount of CPU time used to compute the first ten eigenpair derivatives by each method. It is important to note that the numerical stability of the proposed method is proved.

Comparison of Air Kerma and Absorbed Dose to Water Based Protocols for High Energy Photon Beams: Theoretical and Experimental Study

  • Shin, Dong-Oh;Kim, Seong-Hoon;Seo, Won-Seop;Park, Sung-Yong;Park, Jin-Ho;Kang, Jin-Oh;Hong, Seong-Eon;Ahn, Hee-Kyung
    • 한국의학물리학회:학술대회논문집
    • /
    • 한국의학물리학회 2002년도 Proceedings
    • /
    • pp.241-243
    • /
    • 2002
  • New types of protocols have been recently in development, all based on an absorbed dose-to-water with the aim of improving the accuracy of measurements of absorbed dose to water. IAEA TRS-277, the air-kerma standard-based present protocol, and IAEA TRS-398 and AAPM TG-51, the absorbed dose-to-water standard-based new one, were studied and compared theoretically and experimentally for photon beams of 6, 10, and 15 MV. NE 2571 and 3 Farmer types of ionization chambers in widely commercial use were used to determine an absorbed dose to water at the reference depth in water. Two different kinds of calibration factors were given respectively for every chamber calibrated in $\^$60/CO gamma ray beams from a Korean Secondary Standard Dosimetry Laboratory (KFDA). This work shows that there is around 1 % of difference of absorbed doses measured between two different types of calibration systems owing to different physical parameters and reference conditions used. We hope this work to help form the basis on development of new type of protocol in Korea.

  • PDF

PET-Based Molecular Nuclear Neuro-Imaging

  • Kim, Jong-Ho
    • 대한핵의학회지
    • /
    • 제38권2호
    • /
    • pp.161-170
    • /
    • 2004
  • 분자영상은 살아있는 개체의 몸 속에서 일어나는 생물학적 반응이나 특정한 표적분자를 비관혈적이며 반복적으로 영상화하는 기술이다. 이를 위해서는 두 가지 기본 요소가 요구되는 바 하나는 관심 생물현상에 의해 농도나 분광특성이 변하는 분자영상용 추적자이며 다른 하나는 이런 추적자를 모니터링하는 장비이다. 분자 핵의학 영상기술은 이제 신경과학분야에서도 활발히 적용되고 있으며 신경관련 기초연구나 뇌질환 관련 신약개발에 이미 중요한 역할을 하고 있다. 최근에는 살아있는 개체에서 약제 투여가 뇌에 미치는 약물학적, 생리적 영향을 조사하는 데에도 이용되고 있다. 다가오는 미래에는 각종 뇌질환에서 특이적 표적을 공략하는 새로운 분자치료가 개발되어 뇌질환 치료에 혁명적인 변화를 가져올 것으로 예상되고 있다. 그 예로, 파킨슨씨 병과 같은 퇴행성 신경질환에 줄기세포를 이용한 자가수선, 신경보호, 약물분비 치료, 성장인자와의 병행치료 등이 개발되고, 유전자 치료도 이용될 것으로 보인다. 신경 분자 핵의학 영상은 이와 같은 새로운 뇌질환 치료기술의 개발에 있어서 뇌 안에서 일어나는 분자수준의 변화를 실시간으로 모니터링함으로써 관련연구에 크게 기여할 것으로 기대된다.

Landmark-based Morphometric and Meristic Analysis of Serranidae

  • Lim, Sang Gu;Jeong, Min Hwan;Kim, Bong Seok;Lee, Tae Ho;Gil, Hyun Woo;Park, In-Seok
    • 한국발생생물학회지:발생과생식
    • /
    • 제20권2호
    • /
    • pp.51-63
    • /
    • 2016
  • The landmark-based morphometric and meristic analysis of the kelp grouper (Epinephelus bruneus), red spotted grouper (E. akaara) and seven-banded grouper (E. septemfasciatus) were performed to compare the differentiation of overall body shape and structure. The measurements of the morphometric dimensions were observed in 25 parts (truss dimension: 16 parts; head part dimension: 9 parts) of 38 morphometric dimensions and also meristic differences observed in 3 parts (dorsal fin, anal fin and caudal fin) of 6 meristic counts (P < 0.05). Observed morphometric characteristics primarily involved in truss and head part dimension, kelp grouper have larger values in caudal part of truss dimension, kelp grouper, red spotted grouper and seven-banded grouper have similar values in pectoral part of truss dimension, in addition to, results of head part dimension showed that red spotted grouper have smaller values in overall dimensions (P < 0.05). As meristic characteristics, kelp grouper have more number of anal fin rays than other fish, red spotted grouper have more number of dorsal soft rays than other fish, and seven spotted grouper have more number of anal soft rays, and caudal fin rays than other fish (P < 0.05). Photographed under the x-ray, kelp grouper have the most curved vertebral column and largest swim bladder than other fishes (P < 0.05). Our results of this study confirmed that 3 subfamily fishes adequately can distinguish with external body shape, and we hope that the results of our study could be used to identify in Serranidae family as taxonomical parameters.

Disease and insect damage, growth and yield of sorghum, foxtail millet between rotational upland and continuing upland field

  • Yu, Je Bin;Yoon, Seong Tak;Yang, jing;Han, Tae Kyu;Jeong, In Ho;Kim, Young-Jung;Ye, Min Hee;Lee, Gil Jun;Cho, Soo Been;Lee, Young Kyung
    • 한국작물학회:학술대회논문집
    • /
    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
    • /
    • pp.349-349
    • /
    • 2017
  • This study was performed in order to investigate disease, insect damage, growth and yield characteristics of green maize by organic paddy-upland rotation system. This experiment also was to select optimum variety for organic paddy-upland rotation cultivation. This experiment was conducted at Anseong-si Gyeonggi province of Korea in 2016. The varieties used in this study are green maize of total 8 varieties. Green maize was planted at rotational upland field and continuing upland field and tested for comparison. In case of average occurrence of 4 major diseases for green maize, rotational upland field was higher than that of continuing upland field. Heukjinjuchal and Daehakchal were the lowest occurrence by less than 2% among 8 varieties. Average damage of 8 varieties by Ostrinia furnacalis larva, which is the main pest in green maize was higher in rotational upland field than that of continuing upland field. Chalok 4 and Heugjeom 2 were judged to be resistant varieties to 4 major diseases among 8 varieties. The average yield of green maize per 10a in rotational upland field decreased to 85% level of continuing upland field and Chalok 4 showed the highest yield by 789.0 kg/10a among 8 varieties. The most suitable varieties in organic paddy-upland rotation system were judged to be Chalok 4, Heukjinjuchal and Heukjeom 2.

  • PDF

Effects of Clove Oil and Lidocaine-HCl Anesthesia on Water Parameter during Simulated Transportation in the Marine Medaka, Oryzias dancena

  • Park, In-Seok;Gil, Hyun Woo;Lee, Tae Ho;Nam, Yoon Kwon;Lim, Sang Gu;Kim, Dong Soo
    • 한국발생생물학회지:발생과생식
    • /
    • 제21권1호
    • /
    • pp.19-33
    • /
    • 2017
  • Optimum concentrations of anesthetic clove oil and anesthetic lidocaine-HCl were determined for a species of adult marine medaka, Oryzias dancena, over a range of salinity conditions, and investigated in a transport simulation experiment by analyzing various water and physiological parameters. Research indicated that the higher the concentration of anesthetic at each salinity, the shorter the anesthesia time at each salinity. At each concentration, fish were anesthetized slower at water salinities over 10 ppt (P<0.05). Anesthesia time at 10 ppt was faster than any other salinity. In 10 ppt salinity, the dissolved oxygen (DO) concentrations and respiratory frequencies of the clove-oil-administered groups decreased until 48 hours (P<0.05), whereas the $NH_4{^+}$ and $CO_2$ concentrations increased until 48 hours (P<0.05). In same period, the DO, $NH_4{^+}$, and $CO_2$ concentrations and respiratory frequencies all decreased as the clove oil concentration increased (P<0.05). The trends in the DO, $NH_4{^+}$, and $CO_2$ concentrations and respiratory frequencies in the lidocaine-HCl-administered groups were similar to those in the clove-oil-administered groups. In conclusion, clove oil and lidocaine-HCl are effective anesthetics, improving the transportation of the marine medaka. The results from this study will contribute to safe laboratory handling of the marine medaka, which are commonly required by many research studies and experiments.

서식처 적합성 지수(HSI)를 활용한 맹꽁이 서식처 복원 위치 선정 (Site Selection of Narrow-mouth Frog(Kaloula borealis) Habitat Restoration Using Habitat Suitability Index)

  • 심윤진;조동길;홍진표;김덕호;박용수;성현찬
    • 한국환경복원기술학회지
    • /
    • 제18권2호
    • /
    • pp.33-44
    • /
    • 2015
  • This study was performed to propose the site selection plan for the restoration of the target Narrow-mouth Frog(Kaloula borealis) habitat, and has developed the AHP model to select the optimal site for narrow-mouth frog habitat restoration on the basis of the narrow-mouth frog Habitat Suitability Index (HSI) items (factors and variables). The assessment areas were established by the narrow-mouth frog HSI factors such as space, feed, cover, water(breeding), threatening factors and others, and the sub-assessment items by each assessment area were established based on the narrow-mouth frog HSI variables. The weighting values of the assessment areas and items were calculated by the developed AHP method. The weighting values of the 5 assessment areas were arranged in order as cover(0.283), water(breeding)(0.276), feed(0.230), space(0.147), and threatening factor(0.064). The final weighting values of the 14 assessment items were arranged in order of height as low-rise grassland(0.190), soil quality(0.178), and stones and between the stones(0.105). The scoring criteria according to the assessment items and factors were marked and applied by equal intervals considering the criteria by HSI items of the narrow-mouth frog and finally the scoring criteria diagram has been proposed for the optimal site selection of the narrow-mouth frog habitat restoration.

인간 간암세포주 HepG2에서 팔진항암단과 adriamycin의 병용처리에 의한 항종양 효과 (Anticancer Effect of Combination with Paljinhangahm-dan and Adriamycin on HepG2 Human Malignant Hepatoma Cell Line)

  • 백은기;문구;원진희;김동웅;백동기;윤준철;송봉길;이병호;박상구
    • 동의생리병리학회지
    • /
    • 제17권5호
    • /
    • pp.1243-1250
    • /
    • 2003
  • This study was designed to elucidate the synergistic cytotoxic mechanisms of the co-treatment of adriamycin and Paljinhangahm-dan in human hepatoma malignant cancer cell line, HepG2. The combination of adriamycin and the ethanol extract of Paljinhangahm-dan synergistically augmented the cytotoxicity of Adriamycin and Paljinhangahm-dan in HepG2 cells. The cytotoxicity of two drugs was revealed as apoptosis characterized by DNA fragmentaton in agarose gel electrophoresis. The apoptotic cytotoxicity of adriamycin and Paljinhangahm-dan was accompanied by the cleavage of procaspase -3 protease and PARP. Of note, anti apoptotic Bcl2 protein was obviously decreased, but Fas was dramatically increased in HepG2 cells co-treated with Adriamycin and Paljinhangahm -dan. In addition, through 2-D gel electorphoresis, we observed that the expression levels of a lot of proteins were obviously changed by the status of drug treatments. This results suggest that the synergistic cytotoxicity of the co-treatment of adriamycin and Paljinhangahm-dan might be caused by the changes of the expression levels of a lot of proteins which play pivotal roles in cell survival or death.

아토피 피부염과 심리적 요인에 대한 동서의학적 고찰 (Study about the Comparison of Korean-Western Medicine on Atopic Dermatitis and Psychological Factors)

  • 노현민;박승구;조은희;장현철;김호경;박히준;이길희;박민철
    • 동의생리병리학회지
    • /
    • 제32권2호
    • /
    • pp.113-125
    • /
    • 2018
  • This study aimed to investigate the latest trends in the relationship between atopic dermatitis(AD) and psychological factors(PF) and to examine it in korean medicine. We searched MEDLINE for this analysis with the title "atopic dermatitis" AND ("psychology" OR "psychological" OR "mental" OR "emotion" OR "anxiety" OR "depression") in recent 5 years and searched OASIS on the title "atopy" OR "psychology" OR "emotion" from 2002 to 2017. We selected 23 papers on MEDLINE, 7 papers on OASIS. In western medicine, Stress causes changes in the adrenal nerves, endocrine, and immunological mechanisms and exacerbates dermatitis, which is explained by HPA axis and sympathetic nerve axis, neurogenic inflammation, and cholinergic signals. In Korean medicine, Stress(神) exacerbates AD by affecting the five organs, especially the heart(心), causing inflammation(火熱). We studied the link between AD and PF in Western and Korean medicine. More research is needed in the future.

Value of Bronchoalveolar Lavage Fluid Cytology in the Diagnosis of Pneumocystis jirovecii Pneumonia: A Review of 30 Cases

  • Sung, Ji-Youn;Han, Joung-Ho;Oh, Young-Lyun;Suh, Gee-Young;Jeon, Kyeong-Man;Kim, Tae-Eun
    • Tuberculosis and Respiratory Diseases
    • /
    • 제71권5호
    • /
    • pp.322-327
    • /
    • 2011
  • Background: Pneumocystis jirovecii is a fungus that has become an important cause of opportunistic infections. We present a summary of the clinical status and findings from bronchoalveolar lavage (BAL) of patients with Pneumocystis jirovecii pneumonia (PJP). Methods: We selected 30 cases of PJP that were proven through a surgical specimen evaluation. BAL fluid cytology was reviewed, and agreement with the initial diagnosis was evaluated. Results: All 30 cases of PJP occurred in immunocompromised patients. Only 15 of the 30 cases were initially diagnosed as PJP. We found PJP in 13 of the 15 cases that were negative at the initial diagnosis. The most characteristic finding of PJP was frothy exudates, and BAL fluid tended to show rare neutrophils. Two of seven patients with PJP and diffuse alveolar damage (DAD) revealed no frothy exudates in BAL fluid. Conclusion: BAL fluid cytology was reconfirmed as a sensitive and rapid method to diagnose PJP. We must be aware of the possibility of PJP to maintain high diagnostic sensitivity. We cannot exclude PJP in cases of PJP with DAD, even if frothy exudates are not observed in the BAL fluid.