샌드위치 구조물의 형상최적설계

박철민,박경진,이완익 한양대학교 공학기술연구소 1992 공학기술논문집 Vol.1 No.1

General structural optimization is utilized to minimize the weight of structures while satisfying constraints imposed on stress, displacements and natural frequencies, etc.. Sandwich structures consist of inside core and outside face sheets. The selected sandwich structures are isotropic sandwich beams and isotropic sandwich plate. The face sheets are treated as membrane and assumed to carry only tensions, and the core is assumed to carry only the transverse shear. The characteristics of the varying area are considered by adding the projected component of the tension to the transverse shear. The bending theory and energy method are adopted for analyzing sandwich beams and plates, respectively. In the optimization process, the cost function is the weight of a structure, and a deflection and stress constraints are considered. Design variables are thickness and tapering coefficients which determine the shape of a structure. An existing optimization code is used for solving the formulated problems.

소아 결핵성 뇌막염에 대한 임상적 고찰

김영창,민용식,박준수,정경식,박경배 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.1

A total of 43 cases of tuberculous meningitis in children who were admitted to the pediatric department of Soonchunhyang Chunan hospital and Soonchunhyang Gumi hospital from Jan. 1983 to Dec. 1997 were reviewed clinically. The results were as follows; 1) The incidence of tuberculous meningitis admitted patients has been decreased. 2) The ratio of male to female was 1.5:1. 3) The incidence by age was highest under the age of 1 year (32.6%) and 72.1% of the patient were under 6 years. 4) There were tuberculous patients in the family in 34.9% of all cases. 5) The symptoms on admission were, in order: vomiting, fever, headache, irritability, impaired consciousness, lethargy and convulsion. 6) In the neurological examination on admission, 41.8% of all cases were in a coma or a semicomatose state; Kernig or Brudzinski sign was positive in 51.2% of the cases. 7) The tuberculin skin test was positive in only 14.2% of the cases. 8) On chest X-rays, tuberculous lesion was seen in 32.6%, and miliary patterns were seen in 9.1% of all cases. 9) Brain CT was performed in 8 cases and brain MRI in 1 case, with abnormal findings in 100% of these cases. The brain CT findings were hydrocephalus in 8 cases; basal cisteral enhancement in 2 cases; and infarction and tuberculoma in one case each. 10) In cerebrospinal fluid study, the mean leukocyte count was 174.3/μL (51 to 200/μL). The mean protein level was 154.9 mg/dL. The mean sugar level was 38.7 mg/dL. The mean chloride level was 110.8 mEq/L.. 11) The overall mortality rate was 11.9% and all patients classified as the 3rd stage on admission died.

물질사용장애 환자의 색다른 것을 추구하는 기질

김미영,박제민,윤경일,유택규,권도훈,김성곤,김명정,장기용 대한생물치료정신의학회 2001 생물치료정신의학 Vol.7 No.1

In this study, the relationship between substance use and high-novelty seeking was tested using Cloninger et al's 240-items Temperament and Character Inventory(TCI) in 34 substance users(32 methamphetamine and 2 cocaine dependence disorders), 80 normal controls and 48 schizophrenics Demographic characteristics and substance use-related past history were taken by semi-structured interview. Subjects were aged 18-45 and general psychopathology was screened by Symptom Checklist 90 revised. The results were as follows. 1) Among temperament subdivisions in the TCI, novelty seeking(NS) was significantly higher in the substance users(22.1±4.9) than the normal controls(18.0±5.0) and the schizophrenics(15.6±3.3). There were no significant differences in other temperament subdivisions such as harm avoidance, reward dependence and persistence, neither character subdivisions such as self-directiveness, cooperativeness and self- transcendence. 2) A significant inverse correlation was found between NS and age both in the substance users(r=0.274) and the normal controls(r=0.468). This study suggested that the biogenetic temperament characteristics in substance use disorder were related with their high novelty seeking, not low harm avoidance.

시멘틱 웹 환경에서의 온톨로지 기반의 정보검색

정은경,김영민,변영철,이상준,박경린 濟州大學校 基礎科學硏究所 2003 基礎科學硏究 Vol.16 No.2

온톨로지는 시멘틱 웹을 구현하기 위한 이론이다. 온톨로지는 웹자원의 효과적인 검색, 통합, 재사용을 위한 새로운 기술이고 사람과 이질의 응용 시스템 간에 지식을 공유하고 재사용하기 위한 방법을 제공한다. 온톨로지의 역할은 특별한 개념을 명세화하는 것이다. 도메인과 일반적인 온톨로지는 정보와 지식 시스템을 분석하고 디자인하는 측면에서 공유, 통합, 재사용될 수 있다. 본 연구는 제주도의 숙박과 관광정보를 위한 온톨로지를 디자인하는데 목적이 있다. 그리고 제안된 온톨로지 기반으로 인터넷 웹 검색 시스템을 만드는데 목적이 있다. 본 연구에 의해 클라이언트가 사용하는 표현은 다르지만 뜻이 같은 동의어에 의해 같은 결과를 얻을 수 있다는 것을 알게 되었다. Ontologies are formal theories that are suitable for implementing the semantic web. Which is a new technology that attempts to achieve effective retrieval, integration, and reuse of web resources. Ontologies provide a way of sharing and reusing the knowledge among the people and the heterogeneous application systems. The role of ontologies is that of making explicit specified conceptualizations. In this context, domain and generic ontologies can be shared, reused, and integrated in the analysis and design stage of information and knowledge systems. This study aims to design an ontology for juju lodges and tour, and build an Internet web retrieval system based on the proposed ontologies. This study found that we can take the same result for synonym that cilent use.

Prevalence of coronary atherosclerosis in an Asian population: findings from coronary computed tomographic angiography.

Park, Gyung-Min,Yun, Sung-Cheol,Cho, Young-Rak,Gil, Eun Ha,Her, Sung Ho,Kim, Seon Ha,Jo, Min-Woo,Lee, Moo Song,Lee, Seung-Whan,Kim, Young-Hak,Yang, Dong Hyun,Kang, Joon-Won,Lim, Tae-Hwan,Kim, Beom-Jun Kluwer Academic Publishers 2015 INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING Vol.31 No.3

<P>We sought to estimate the prevalence of coronary atherosclerosis by coronary computed tomographic angiography (CCTA) and to identify risk factors attributable to the development of coronary atherosclerosis in an asymptomatic Asian population. We analyzed 6,311 consecutive asymptomatic individuals aged 40 and older with no prior history of coronary artery disease (CAD) who voluntarily underwent CCTA evaluation as part of a general health examination. The mean age of study participants was 54.7 7.4 years, and 4,594 (72.8%) were male. After age and gender adjustment using the population census of the National Statistical Office, the prevalence of plaque was 40.5% [95% confidence interval (CI) 38.1-42.9], and significant CAD (diameter stenosis 50%) was observed in 9.0% (95% CI 7.7-10.2). Individuals with significant CAD were significantly older than those without (59.2 8.8 vs. 54.0 7.1 years, p < 0.001). Compared with individuals with no cardiovascular risk factors, there was a higher prevalence of significant CAD in individuals with diabetes mellitus [standardized rate ratio (SRR) 2.66; 95% CI 1.93-3.68; p < 0.001], hypertension (SRR 2.24; 95% CI 1.69-2.97; p < 0.001), or hyperlipidemia (SRR 1.65; 95% CI 1.25-2.17; p < 0.001). There was also a greater prevalence of significant CAD in individuals with an intermediate or high Framingham risk score (SRR 5.91; 95% CI 2.34-14.95; p < 0.001) or a high atherosclerotic cardiovascular disease risk score (SRR 8.04; 95% CI 3.04-21.23; p < 0.001). The prevalence of coronary atherosclerosis in this Asian population was not negligible and was associated with known cardiovascular risk factors and high-risk individuals.</P>

Monitoring of an electrically induced signal in melon in relation to different environmental conditions in a smart farm

Park Jin Hee,Park Gyung Min,Kim Eun Jeong,Jeon Yu Min 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.6

A smart farm that automatically regulates environmental conditions such as temperature, humidity and nutrient supply will maximize crop production per unit area by using ICT-based technology. To control the environment in a smart greenhouse, plant growth should be monitored in real time. The physiological activity of a plant was monitored by receiving an electrical signal from inside the plant stem which changed when the plant absorbed nutrients and water. In this study, the environmental conditions in different areas of a smart farm were not much different, and growth parameters were not much affected by the environmental conditions of the area. However, a plant induced electrical signal (PIES) was associated with the atmospheric and media temperature and relative humidity although there was time lag of 6 ~ 7 h for the peaks of the PIES and other environmental conditions. Therefore, monitoring a PIES will make it possible to improve the growth environments in smart farms. A smart farm that automatically regulates environmental conditions such as temperature, humidity and nutrient supply will maximize crop production per unit area by using ICT-based technology. To control the environment in a smart greenhouse, plant growth should be monitored in real time. The physiological activity of a plant was monitored by receiving an electrical signal from inside the plant stem which changed when the plant absorbed nutrients and water. In this study, the environmental conditions in different areas of a smart farm were not much different, and growth parameters were not much affected by the environmental conditions of the area. However, a plant induced electrical signal (PIES) was associated with the atmospheric and media temperature and relative humidity although there was time lag of 6 ~ 7 h for the peaks of the PIES and other environmental conditions. Therefore, monitoring a PIES will make it possible to improve the growth environments in smart farms.

Ecotoxicological Evaluation of Sewage Sludge Using Bioluminescent Marine Bacteria and Rotifer

Park, Gyung-Soo,Chung, Chang-Soo,Lee, Sang-Hee,Hong, Gi-Hoon,Kirn, Suk-Hyun,Park, Soung-Yun,Yoon, Seong-Jin,Lee!, Seung-Min The Korean Society of Oceanography 2005 Ocean science journal Vol.40 No.2

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

Impact of desalination byproducts on marine organisms: A case study at Chuja Island Desalination Plant in Korea

Park, Gyung Soo,Yoon, Seok-Min,Park, Kwang-Seok Balaban Publishers 2011 Desalination and Water Treatment Vol. No.

<P> Desalination of seawater has become an important and growing industry due to the present water shortage in the world. However, the desalination may result in environmental impacts, mainly derived by the discharge into adjacent coastal waters of brine and additives produced during the desalination processes (e.g., biocides and membrane cleaning chemicals). To measurement of environmental impact by desalination, we approached environmental impact assessment (EIA) procedure [1] for the desalination plant of Chuja Island in South Korea. We conducted a series of marine bioassays using three phytoplankton, rotifer, benthic copepod and one fish species for source water, discharged brine waters and chemical additives. There was no significant toxicity of brine discharge on tested organisms but high toxicity was found at the chemical additives as chlorine and membrane cleaning chemical. In terms of the habitat susceptibility it is located in relatively insensitive habitat, open rocky shore with gravel bottom. Based on these results, even the environmental impacts by Chuja desalination plant were not significant currently, monitoring strategies have to be established and conducted to estimate long-term effects from desalination in marine ecosystem such as hard-bottom benthic monitoring along the shorelines of brine discharged area and toxicity estimation of byproducts and chemical additives using local representative marine species. </P>

Molecular Detection and Genetic Analysis of Porcine Bocavirus in Korean Domestic Swine Herd

Min gyung Choi,Seong jun Park,Giap Van Nguyen,Hee chun Chung,A reum Kim,Bong kyun Park 대한수의학회 2013 대한수의학회 학술대회발표집 Vol.2013 No.-

Ecotoxicological Evaluation of Sewage Sludge Using Bioluminescent Marine Bacteria and Rotifer

Gyung Soo Park,정창수,홍기훈,김석현,박승윤,Sang Hee Lee,seong Jin Yoon,Seung Min Lee 한국해양과학기술원 2005 Ocean science journal Vol.40 No.2

using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.