자원 제약 조건이 공기-비용 교환 문제에 미치는 영향 분석

홍성준,류한국,유정호,이현수 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

It has been generally accepted that cost and time are in reverse proportion. But, due to the resource constraints such as resource capacity, resource availability, resource continuity and resource level, time and cost could have unfixed relation and time-cost trade-off curves could take various forms. This study proposes the labor-related constraints affecting the time-cost trade-off problems and analyzes the effects.

소방구급대원의 응급처치 적절성 평가와 재교육 필요성

류석용,김원율,김경환,이상래,이경호,김홍용,이승한 대한응급의학회 2000 대한응급의학회지 Vol.11 No.2

Background: The prehospital emergency medical system(EMS) for 119 rescue has progressed considerably, but leaves much to be desired. To improve prehospital EMS, we need to evaluate prehospital patient care, and reeducation. Methods: The records of 1,882 patients, who visited Sanggye Paik Hospital Emergency Department via 119 rescue from April 1 to July 30, 1999, were analyzed according to the quality of patient care as documented by the 119 rescue protocol and database. Patients are grouped into 5 classes based on the quality of the care received. Class 1A received adequate care, class 1B received inadequate care, class 1C did not receive the necessary care, and class 2A received unnecessary care, class 2B did not receive unnecessary care. The results of such analyses are presented to the fireman at monthly meetings, thus reeducating them. Results: The overall results were 1027 cases in Class 1A(55%), 83 in 1B(4%), 149 in 1C(8%), 21 in 2A(1%), and 602 in 2B(32%). Well performed care(1A+2B) occured in 1629 cases(87%) and badly performed care(1B+1C+2A) occured in 253cases(13%). Well perfomed care gradually increased from April to July (April 83%, May 85%, June 87%, and July 89%). Conclusion: Meticulous appraisal of the quality of prehospital patient care and reeducation through the regular meetings of EMS physicians and firemen in each community is needed for developing a model protocol for indirect retrospective medical control of the prehospital EMS.

오리 網膜에 存在하는 神經節細胞의 數와 分布에 關한 硏究

姜翰秀,金武剛,申台均,金弘善,柳時潤,李永浩 충남대학교 의과대학 지역사회의학연구소 1986 충남의대잡지 Vol.13 No.1

The number and distribution of the retinal ganglion cells in the 1-week-old and 7-week-old ducks were determined from whole flat mounted preparations stained with methylene blue and thionin. The results were summarized as follows. 1. In the 1-week-old and 7-week-old ducks, the areas of the retinas were 269.4㎟ and 357.2㎟, respectively, and the total cell numbers 1,742,800 and 1,808,800, respectively. 2. The ganglion cells based upon soma diameter were classified into 3 groups such as small (below 10㎛), medium (10-20㎛) and large (above 20㎛) ganglion cells. In 1-week-old duck, the relative frequencies of these 3 groups were 91.0%, 8.5% and 0.5%, respectively, and in 7-week-old duck, 83.7% 14.7% and 1.6%, respectively. 3. Area centralis was located at the distance of 1.6mm (1-week-old) and 2.0mm(7-week-old) nasal side from the anterior tip of the pecten. The number of ganglion cells in the area centralis was 11,000 cells/㎟ (1-week-old) and 12,000 cells/㎟ (7-week-old). 4. There was a gradual decrease in density of retinal ganglion cells extending from area centralis to the periphery of retina. 5. The density of the large (above 20㎛) ganglion cells was higher in the peripheral regions than in the center of retina. Higher densities were noted in the superior-temporal region in 7-week-old duck, and in the nasal region in 1-week-old duck than in the other regions. 6. The direction of the beak tip is approximately 30° in 1-week-old and 26° in 7-week-old duck from the angle of the pecten.

국내 하천 퇴적물 건강성평가를 위한 Microtox 독성시험 조건확립 연구

정홍배,박정규,문성환,류태권,김소정,배철한,황인영 한국환경독성학회 2001 환경독성보건학회지 Vol.16 No.4

1. 하천 퇴적물 공극수, 증류수 추출용액 및 유기용매 추출액을 pH6.0~6.5 범위로 조절한 후 Microtox 독성을 측정하는 것이 퇴적물내의 암모니아 독성이 배제된, 유해화학물질 오염에 의한 퇴적물 독성을 평가하는 방안임을 확인하였다. 2. 퇴적물에 대해 공극수, 증류수 추출물, 유기용매 추출물 구분하여 Microtox 독성을 구하는 것이 퇴적물 내 유해화학물질의 독성발현 특성을 예측할 수 있는 기법이라고 사료된다. 3. 조사정점 내 시료 채취 지점간 독성에 편차로 인하여, 동일 정점의 반경 50~100m 내에서 최소 4지점 이상의 퇴적물을 확보하는 것이 해당 정점의 독성 대표값을 산출할 수 있는 방안이 된다고 판단된다. 4. 한강수계인 남한강 지천인 복하천과 양화천, 금강수계인 청주 미호천, 대전 갑천, 낙동강수계인 대구 금호강, 영산강수계인 황룡강 그리고 익산 만경강을 대상으로 한 예비 조사한 결과, 집중연구대상 하천으로의 조건은 금호강이 가장 우수하였다. 5. 하천 퇴적물의 증류수 추출액과 유기용매 추출액의 Microtox 독성값 간의 상호 상관성이 높았다. 그러나, 농축 과정이 용이하므로 정점간 비교를 위한 독성 측정시 유기용매 추출액을 사용하는 것이 바람직하다고 사료되었다. Six rivers were selected as preliminary screening sites to determine the test conditions of Microtox in assessing the toxicity of the sediment. In addition, a pH range of 6.0--6.5 was established in testing pore water, aqueous extracts and organic extracts. Each extractable fraction of sediment showed different toxicities. Therefore, in order to properly examine the toxicity in the sediment, all extractable fractions of sediment samples needed to be tested with Microtox. Thus, sediment samples were additionally collected from at least 4 secondary sites within 50~100 m area of the primary sampling site to reduce any variation or deviation in toxicity assessment. From all sediment toxicity data that was collected from this study, it was concluded that the Keumho river was the most polluted with the highest sediment toxicity of all the rivers analyzed and needed further detailed research on its pollution problem.

3종 페라이트/고무 복합형 전파흡수체에 있어서 재료정수의 주파수 의존성

김철한,전홍배,유영준,사공건 東亞大學校 1999 東亞論叢 Vol.36 No.-

In this study, ferrite/rubber composite specimens have prepared by molding and curing the mixture of matrix silicon rubber and three kinds of filler particle Mn-Zn/Ni-Zn/Ni₂Y ferrite which are synthesized by the coprecipitation mehtod. The mixing ratio of three kinds of ferrite filler paticle gave variety to adjust the material constant of composite microwave absorbers. Material constants of composite specimens were calculated from the measured variables(s-parameter) over the frequency range from 1 to 12 GHz by means of Network Analyzer(HP8722D) with a co-axial type air line. The reflection loss was calculated from material constants on the impedance matching map utilizing simplex method. By chaging mixing ratio of three kinds of ferrite filler particle, the frequency range over than 20dB were relatively broaden and maximum reflection loss were remarkably reduced to others specimens excepted specimen D. Finally, it could make microwave absorber to be used for C-band frequency range.

김치가 노화촉진쥐 뇌의 유리기 생성 및 항산화효소 활성에 미치는 영향

김종현,류재두,이한기,박정희,문갑순,최홍식,송영옥 부산대학교 김치연구소 2002 김치의 과학과 기술 Vol.8 No.-

본 연구는 김치가 노화와 직접적인 관련이 있는 유리기 생성 및 항산화 효소활성에 미치는 영향을 살펴보기 위하여 배추김치, 배추갓김치 그리고 갓김치를 식이중량의 5% 첨가하여 실험식이를 제조하여 이를 노화촉진쥐인 SAMP8에게 1년간 섭취시켰다. 총유리기, OH radical, H_2O_2농도 그리고 TBARS 농도 모두 가령에 따라 증가하였으며, 김치섭취시 유의적으로 감소되었다(p<0.05), 김치군에 있어서 생성된 유리기를 제거하기 위해 항산화계 효소인 SOD, catalase, GSH-px 그리고 GSH/GSSG는 모든 김치군에서 유의적으로 증가 하였다(P<0.05). 따라서 김치섭취는 먼저 가령에 의해 생성되는 유리기의 생성은 억제시키면서, 둘째 이를 제거하기 위한 항산화계 효소 활성은 더욱 활성화시키므로써 항노화 기능을 발휘한다고 생각된다. 김치종류 중에서는 배추갓김치와 갓김치가 배추김치보다 유리기 생성을 억제하고, 항산화계 활성을 증진시킨 것으로 보아 이들의 항노화 효과가 클것으로 생각된다. This study was performed to investigate the effect of kimchi intake on antiaging characteristics in the brain of senescence-accelerated mouse (SAM) in terms of free radical production and anti-oxidative enzymes. Two hundreds twenty SAM (20 mice) were divided into four groups and fed kimchi diet for 12 months. Experimental groups were kimchi free AIN-76 diet (control) group, Korean cabbage kimchi diet (KCK)group, 30% mustard leaf added Korean cabbage kimchi diet (MKCK) group, and mustard leaf kimchi diet (MLK) group. Concentrations of total free radical, OH radical and H_2O_2 of control group increased up to 123%, 262% and 174% of initial value (p<0.05) after one year. Increase in free radical production in kimchi groups due to aging was decreased by kimchi feeding. Among kimchi groups. MKCK and MLK groups showed greater inhibiting effect against free radical production than KCK. The concentration of TBARS in the bruin of control group also significantly increased up to 362% of initial value as aged (p<0.05) and production of TBARS in kimchi groups were decreased. When the activities of Cu, Zn-SOD, Mn-SOD, GSH-px and catalase of kimchi groups were compared to those of control at the same experimental period, anti-oxidative enzyme activities of kimchi groups were lower than those of control (p<0.05). But GSH/GSSG in kimchi groups were higher compared to control. In conclusion, decrease in free radical production and increase in anti-oxidative enzyme activities were observed from kimchi groups suggesting that kimchi might have important role on retarding aging. Among kimchi variety tested in this experiment, MKCK and MLK seem to have greater effect on inhibiting free radical production and increasing anti-oxidative enzyme activities than KCK.

Spatial Distribution of Yield Characteristics of Soybean Based on Drought and Humidification by Soybean

Hong-Seok Lee(이홍석),Duk-yeong Song(송득영),Won-Young Han(한원영),Kil-su Han(한길수),Jong-Soo Ryu(류종수),Jae-sung Park(박재성),Eun-ji Suh(서은지),Ok-jae Won(원옥재),Seo-yeon Hong(홍서연),Jin-ki Park(박진기) 한국토양비료학회 2020 한국토양비료학회 학술발표회 초록집 Vol.2020 No.10

Clinical Features of Adult COVID-19 Patients without Risk Factors before and after the Nationwide SARS-CoV-2 B.1.617.2 (Delta)-variant Outbreak in Korea: Experience from Gyeongsangnam-do

Ryu Byung-Han,Hong Sun In,Lim Su Jin,Cho Younghwa,Hwang Cheolgu,Kang Hyungseok,Kim Si-Ho,Wi Yu Mi,Hong Kyung-Wook,Bae In-Gyu,Cho Oh-Hyun 대한의학회 2021 Journal of Korean medical science Vol.36 No.49

Background: Data on severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) delta variant virulence are insufficient. We retrospectively compared the clinical features of adult coronavirus disease 2019 (COVID-19) patients without risk factors for severe COVID-19 who entered residential treatment centers (RTCs) before and after the delta variant outbreak. Methods: We collected medical information from two RTCs in South Korea. On the basis of nationwide delta variant surveillance, we divided the patients into two groups: 1) the delta-minor group (diagnosed from December 2020–June 2021, detection rate < 10%) and 2) the delta-dominant group (diagnosed during August 2021, detection rate > 90%). After propensity-score matching, the incidences of pneumonia, hospital transfer and need for supplemental oxygen were compared between the groups. In addition, risk factors for hospital transfer were analysed. Results: A total of 1,915 patients were included. The incidence of pneumonia (14.6% vs. 9.2%, P = 0.009), all-cause hospital transfer (10.4% vs. 6.3%, P = 0.020) and COVID-19- related hospital transfer (7.5% vs. 4.8%, P = 0.081) were higher in the delta-dominant group than those in the delta-minor group. In the multivariate analysis, the delta-dominant group was an independent risk factor for all-cause (adjusted odds ratio [aOR], 1.91; 95% confidence interval [CI], 1.16–3.13; P = 0.011) and COVID-19-related hospital transfer (aOR, 1.86; 95% CI, 1.04–3.32; P = 0.036). Conclusion: Hospitalization rates were increased in the adult COVID-19 patients during the delta variant nationwide outbreak. Our results showed that the delta variant may be more virulent than previous lineages.

High performance of InGaN light-emitting diodes by air-gap/GaN distributed Bragg reflectors.

Ryu, Jae Hyoung,Kim, Hee Yun,Kim, Hyun Kyu,Katharria, Yashpal Singh,Han, Nam,Kang, Ji Hye,Park, Young Jae,Han, Min,Ryu, Beo Deul,Ko, Kang Bok,Suh, Eun-Kyoung,Hong, Chang-Hee Optical Society of America 2012 Optics express Vol.20 No.9

<P>The effect of air-gap/GaN DBR structure, fabricated by selective lateral wet-etching, on InGaN light-emitting diodes (LEDs) is investigated. The air-gap/GaN DBR structures in LED acts as a light reflector, and thereby improve the light output power due to the redirection of light into escape cones on both front and back sides of the LED. At an injection current of 20 mA, the enhancement in the radiometric power as high as 1.91 times as compared to a conventional LED having no DBR structure and a far-field angle as low as 128.2° are realized with air-gap/GaN DBR structures.</P>

Reduced thermal resistance of heat sink using graphene oxide decorated with copper nanoparticles

Ryu, Beo Deul,Han, Min,Ko, Kang Bok,Lee, Kyu-Han,Cuong, Tran Viet,Han, Nam,Kim, Kyurin,Ryu, Jae Hyung,Park, Noh-Joon,Lim, Yongsu,Thanh, Do Trong,Jo, Chang Hee,Ju, Kwanseon,Hong, Chang-Hee Elsevier 2019 Materials research bulletin Vol.110 No.-

<P><B>Abstract</B></P> <P>Three–dimensional thermal interface materials made of graphene oxide (GO) and copper nanoparticles (Cu NPs) were applied for enhancing light–emitting diode heat dissipation. The effect of the stacking order of GO and Cu NPs on thermal resistance was explored by creating two types of samples: spray–coated with a mixed GO–Cu NPs and layer–by–layer stacked with GO/Cu NPs/GO. A reduction of thermal resistance for mixed GO–Cu NPs and layer–by–layer stacked structure by 37% and 33%, respectively, compared to that of Al heat sink. The lower thermal resistance of the mixed GO–Cu NPs sample is attributed to the fact that distributed Cu NPs at the step edge of GO sheets enhances the out–of–plane heat transfer at wrinkles/folds of GO interlayers. Therefore, a mixed GO–Cu NPs is considered as a promising composite for effective thermal management of high–performance optoelectronic devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three–dimensional thermal interface materials made of graphene oxide and copper nanoparticles (GO–Cu NPs) have synthesized. </LI> <LI> The effect of the stacking order of GO–Cu NPs on thermal resistance has explored for enhancing LED heat dissipation. </LI> <LI> Analysis by a FLIR camera has showed that the combination of GO and Cu NPs enabled heat dissipation properties. </LI> <LI> The thermal resistance of the mixed GO–Cu NPs structure is less 37 % than that of the Al heat sink. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>