공학 수업 동영상 분석을 통한 교수전략 활용 실태

신영화(Younghwa Shin),김동익(Dongik Kim),홍경선(Kyungsun Hong) 한국공학교육학회 2012 공학교육연구 Vol.15 No.6

The purposes of this article are to analyze the conditions of using instructional strategies and using gender sensitive instructional strategies at engineering classes of K University. Qualitative analysis methods were adapted. To achieve the purposes, 35 hours of engineering classes from 11 professors from 9th to 20th of November 2009 were videotaped and analyzed. The research findings were discussed by the checklists for general and gender sensitive the instructional strategies which were recommended for the managing the better classes. Students are influenced by professors not only knowledge and skills but also values and attitudes. Professors who take gender sensitive instructional strategies are expected to give good influence the women students.

NUMERICAL SIMULATION OF INTERPLAY BETWEEN ECOSYSTEM AND THE ASIAN MONSOON CLIMATE

Jinkyu HONG,Kyung-Hee SEOL,Younghwa BYUN,Chunho CHO,Taeyoung HA,Joon KIM 한국산업응용수학회 2010 한국산업응용수학회 학술대회 논문집 Vol.5 No.2

The monsoon system is an important natural driver of ecosystem carbon and water exchanges in Asia and is being altered by anthropogenic forcings. This system is accompanied by heavy rainfall and typhoons in the main growing season, thus causing alterations of environmental conditions such as rainfall, wind, and temperature; therefore, it acts as a natural disturbance to forests in Asia. Therefore, degradation of ecosystem service by monsoon activity reinforced by anthropogenic factors in a changing climate is of great concern. In this study, we presented observational evidences for the interplay of terrestrial carbon and water dynamics with the Asian monsoon and their implication in ecosystem modeling. Our analysis showed strong coupling between ecosystem functioning and temporal variations of monsoon climate. Further scrutiny on the model outputs showed that the model did not accurately reproduce the observed plant phenology and thus ecosystem carbon and water exchanges disturbed by monsoon activities. Our findings suggest that under projected climate scenarios, terrestrial carbon sinks in monsoon Asia will decline if the monsoon disturbance will exceed its natural range of variation and if there is no enhancement in the robustness of the ecosystem in this region.

Inductin of neuron-derived orphan receptor-1 in the dentate gyrus of the hippocampal formation following transient global ischemia in the rat.

Kim, Younghwa,Hong, Soontaek,Noh, Mi Ra,Kim, Soo Young,Huh, Pil Woo,Park, Sun-Hwa,Sun, Woong,Kim, Hyun Korean Society for Molecular Biology 2006 Molecules and cells Vol.22 No.1

<P>Neuron-derived orphan receptor (NOR-1) is a member of the thyroid/steroid receptor superfamily that was originally identified in forebrain neuronal cells undergoing apoptosis. In addition to apoptotic stimuli, activation of several signal transduction pathways including direct neuronal depolarization regulates the expression of NOR-1. In this study we tested whether the expression of NOR-1 is changed following transient ischemic injury in the adult rat brain. NOR-1 mRNA increased rapidly in the dentate gyrus of the hippocampal formation and piriform cortex 3 h after transient global ischemia and returned to basal level at 6 h. On the other hand, oxygen-glucose deprivation of cultured cerebral cortical neurons did not alter the expression of NOR-1. These results suggest that expression of NOR-1 is differentially regulated in different brain regions in response to globally applied brain ischemia, but that hypoxia is not sufficient to induce its expression.</P>

UVB로 손상된 인간 피부 섬유아세포에서 대추 물 추출물의 피부 보호 효과

홍성화(Seonghwa Hong),이하나(Hana Lee),정택영(Taekyoung Jeong),김영화(Younghwa Kim),정헌상(Heon Sang Jeong),이준수(Junsoo Lee) 한국식품영양과학회 2019 한국식품영양과학회지 Vol.48 No.10

피부 노화는 시간의 흐름에 따른 생리적 노화과정과 외인적 요인에 의한 노화과정으로 나누어진다. 피부 노화에 영향을 미치는 외부인자들 중 자외선에 의한 노화를 광노화라고 한다. 본 연구는 Hs68 세포를 이용하여 대추 물 추출의 피부광노화에 대한 보호 효과를 평가하였다. 대추 물 추출물은 50.0 μg/mL까지 세포독성을 보이지 않았고, UVB 자극에 대한 보호 효과는 모든 농도에서 유의적으로 증가하였으며, 특히 25.0, 50.0 μg/mL 농도에서는 ascorbic acid 100 μM과 비슷한 수준의 광노화 보호 효과가 나타났다. 대추 물 추출물은 UVB 조사로 유도된 ROS의 생성량을 60분대에 12.5, 25.0, 50.0 μg/mL 농도에서 각각 21, 25, 27% 감소시켜 피부의 산화적 손상을 억제하였다. 또한 대추 물 추출물이 UVB에 의한 MMP-1과 MMP-3의 생성량 증가를 유의적으로 억제하였으며, UVB에 의해 감소한 콜라겐 생성량을 유의적으로 증가시켰다. 본 연구를 통해 대추의 물 추출물이 UVB로부터 인간 피부 섬유아세포에서 보호 효과를 나타냄을 확인하였다. 따라서 대추 물 추출물이 광노화에 보호 작용을 갖는 기능성 화장품 소재로 활용될 수 있을 것으로 기대된다. Skin is damaged by intrinsic and extrinsic factors, such as aging, ultraviolet (UV) light, and pollutants. UV irradiation induces the synthesis of matrix metalloproteinases (MMPs) and collagen degradation, which in turn causes skin photoaging and photocarcinogenesis. This study examined the anti-photoaging activity of jujube water extract (JWE) against UVB-induced damage in human fibroblast (Hs68 cells). The JWE did not show any cytotoxicity up to 50 μg/mL. Treatment with JWE prevented UVB-induced cytotoxicity in Hs68 cells. The protective effect of JWE appeared to be mediated by inhibiting intracellular reactive oxygen species by 21, 25, and 27% at a concentration of 12.5, 25.0, and 50.0 μg/mL, respectively. UVB increased the production of MMP-1/3 and decreased collagen synthesis. On the other hand, treatment of JWE attenuated the UVB-induced production of MMP-1/3 and prevented the reduction of collagen. These results suggest that JWE has a considerable inhibitory effect on the photoaging induced by UVB irradiation. This study showed that JWE could be used as a photo protective agent in cosmetic products.

Design of ITER divertor VUV spectrometer and prototype test at KSTAR tokamak

Seon, Changrae,Hong, Joohwan,Song, Inwoo,Jang, Juhyeok,Lee, Hyeonyong,An, Younghwa,Kim, Bosung,Jeon, Taemin,Park, Jaesun,Choe, Wonho,Lee, Hyeongon,Pak, Sunil,Cheon, MunSeong,Choi, Jihyeon,Kim, Hyeonse Springer-Verlag 2017 The European physical journal. D, Atomic, molecula Vol.71 No.12

<P>Design and development of the ITER divertor VUV spectrometer have been performed from the year 1998, and it is planned to be installed in the year 2027. Currently, the design of the ITER divertor VUV spectrometer is in the phase of detail design. It is optimized for monitoring of chord-integrated VUV signals from divertor plasmas, chosen to contain representative lines emission from the tungsten as the divertor material, and other impurities. Impurity emission from overall divertor plasmas is collimated through the relay optics onto the entrance slit of a VUV spectrometer with working wavelength range of 14.6-32 nm. To validate the design of the ITER divertor VUV spectrometer, two sets of VUV spectrometers have been developed and tested at KSTAR tokamak. One set of spectrometer without the field mirror employs a survey spectrometer with the wavelength ranging from 14.6nm to 32nm, and it provides the same optical specification as the spectrometer part of the ITER divertor VUV spectrometer system. The other spectrometer with the wavelength range of 5-25nm consists of a commercial spectrometer with a concave grating, and the relay mirrors with the same geometry as the relay mirrors of the ITER divertor VUV spectrometer. From test of these prototypes, alignment method using backward laser illumination could be verified. To validate the feasibility of tungsten emission measurement, furthermore, the tungsten powder was injected in KSTAR plasmas, and the preliminary result could be obtained successfully with regard to the evaluation of photon throughput.</P>

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.

Ballasting plan optimization for operation of a 2D floating dry dock

Kyungho Yoon,김효진,Seungkyun Yeo,Younghwa Hong,Jihye Cha,정현 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.4

A floating dry dock is an advanced structure that can provide a solution for dry dock space shortages. The critical point in floating dock operation is compensating the deflection caused by a heavy payload by adjusting the water level in the ballast system. An appropriate ballasting plan warrants safe and precise construction on a floating dock. Particularly, in the case of a 2D floating dock, ballasting plan evaluation is crucial due to complex deformation modes. In this paper, we developed a method to calculate the optimal ballasting plan for accurate and precise construction on a 2D floating dock. The finite element method was used for considering the flexibility of the floating dock as well as the construction blocks. Through a gradient-based optimization algorithm, the optimal ballasting plan for the given load condition was calculated in semi-real time (5 min). The present method was successfully used for the actual construction of an offshore structure on the 2D floating dock.

Atmospheric Combustion Chemical Vapor Deposition for High Functional Application

Dongyoeul Lee,YoungJin Kwak,KyungHoon Nam,Younghwa Jung,Woosung Jung,Munjong Eom,Seokjun Hong,Taeyeob Kim,Changsik Ha 한국표면공학회 2010 한국표면공학회 학술발표회 초록집 Vol.2010 No.11

Different from conventional PVD and CVD process, Combustion Chemical Vapor Deposition (CCVD) is environmental friendly vapor deposition process based on atmospheric pressure with thermal energy from combustion. CCVD equipment is consisted of reservoir of hydrocarbon fuel and precursor, gas mixing burner, sample carrier and control system. The combustion energy from gas mixture of hydrocarbon, propane and precursor, HMDSO(Hexamethyldisiloxane) saturated air generates chemical reaction of pyrolysis and oxidation of precursor to form silicon oxide layer on the steel substrate. Because of hydroxide in dense silicon oxide layer, even though its thickness is just scores of nanometers, CCVD treated steel surface shows greatly improved wetting ability, adhesion with organic resin and coating. When the organic resin coating containing polar functional group, for example, carbonyl, acetate and hydroxyl functional group applied on CCVD treated steel surface, covalent chemical bond seems to be generated between hydroxide of CCVD layer and functional group of organic resin and adhesion between organic resin layer and substrate and corrosion resistance of substrate is highly promoted. Ultra thin silicon oxide layer of CCVD is analyzed its structure by atomic force microscopy(AFM), optical 3D profiler and ellipsometer.

Changes in the Prevalence of Childhood Asthma in Seoul from 1995 to 2008 and Its Risk Factors

Kwon, Ji-Won,Kim, Byoung-Ju,Song, Younghwa,Seo, Ju-Hee,Kim, Tae-Hee,Yu, Jinho,Kim, Hyo Bin,Lee, So Yeon,Kim, Woo-Kyung,Kim, Kyoung-Won,Ji, Hye-Mi,Kim, Kyu-Earn,Kim, Ho,Hong, Soo-Jong The Korean Academy of Asthma, Allergy and Clinical 2011 Allergy, Asthma & Immunology Research Vol.3 No.1

<P><B>Purpose</B></P><P>To investigate the prevalence of asthma and determine its risk factors in elementary school students in Seoul.</P><P><B>Methods</B></P><P>A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to survey 4,731 elementary school students from five areas in Seoul between April and October, 2008.</P><P><B>Results</B></P><P>In elementary school children, the lifetime and recent 12-month prevalence of wheezing were 11.7% and 5.6%, respectively. The lifetime prevalence of asthma diagnosis was 7.9%, and the recent 12-month prevalence of asthma treatment was 2.7%. Male sex (adjusted odds ratio [aOR], 1.90; 95% confidence interval [CI], 1.36-2.66), history of atopic dermatitis (AD) (aOR, 2.76; 95% CI, 1.98-3.84), history of allergic rhinitis (AR) (aOR, 3.71; 95% CI, 2.61-5.26), history of bronchiolitis before 2 years of age (aOR, 2.06; 95% CI, 1.39-3.07), use of antibiotics during infancy for >3 days (aOR, 1.88; 95% CI, 1.35-2.62), parental history of asthma (aOR, 2.83; 95% CI, 1.52-5.27), exposure to household molds during infancy (aOR, 1.84; 95% CI, 1.18-2.89), and the development or aggravation of asthma symptoms within 6 months after moving to a new house (aOR, 11.76; 95% CI, 5.35-25.86) were the independent risk factors for wheezing within 12 months.</P><P><B>Conclusions</B></P><P>The prevalence of wheezing and asthma in elementary school students in 2008 was similar to that in the past decade. Male sex, history of AD, history of AR, history of bronchiolitis before 2 years of age, parental asthma, use of antibiotics during infancy, exposure to molds in the house during infancy, and development or aggravation of asthma symptoms within 6 months after moving to a new house, could be risk factors for wheezing within 12 months.</P>

드론 방제기 비산 측정을 위한 비산 입자 수집장치 설계

이춘구 ( Chun-gu Lee ),최용 ( Yong Choi ),최일수 ( Ilsu Choi ),김영화 ( Younghwa Kim ),우제근 ( Jea-keun Woo ),문석표 ( Seok Pyo Moon ),이상봉 ( Sangbong Lee ),이지근 ( Jee-keun Lee ),홍세운 ( Se-woon Hong ),유승화 ( Seung-hwa Yu 한국농업기계학회 2023 한국농업기계학회 학술발표논문집 Vol.28 No.2

병해충이 발생하면 작물의 생산량이 큰 폭으로 감소하여 이를 막기 위한 방제작업은 반드시 필요하다. 그러나 방제 중 살포하는 농약으로 인한 환경오염 및 농산물 잔류가 문제시 되고 있다. 국내에서는 2019년부터 농약 허용 기준 강화제도(Positive List System, PLS)가 시행되어 농산물의 잔류 농약에 대해 관리하고 있다. 최근 증가하는 무인항공기를 이용한 항공 방제의 경우 높은 고도에서 살포하는 만큼 약제의 일부가 비산될 가능성이 있으며 이는 이웃한 경작지에 PLS 위반이라는 피해를 불러일으킬 수 있다. 이를 대비하기 위하여 드론 방제기의 비산량 및 비산거리를 측정하는 방법 마련이 필요하나 국내에서 비산측정에 대한 연구가 부족한 상황이다. 이에 따라 본 연구에서는 비산 측정과 관련된 국제표준인 ISO 22866을 참조하여 비산 입자 측정을 위한 수동 수집 장치를 설계하고자 하였다. 우선 ISO 표준을 참조하여 수집 효율이 좋고 단면적을 명확하게 계산할 수 있는 polyethylene(PE) 튜브를 수집기로 사용하고자 하였다. 수집기 설치는 붐방제기에 대한 기준을 참조하여 지면으로부터 4m 높이까지 1m 간격으로 설치하고자 하였다. 이에 따라 수집기를 설치할 수집 장치의 높이는 4.5m로 설정하였다. 이송 및 보관의 편리성을 위하여 수집 장치는 받침부와 2m 길이의 상·하부 기둥으로 분리하였고 현장에서 조립할 수 있도록 하였다. 설계안을 검토하여 실제 제작한 후 향후 드론 방제기의 비산 측정 실험에 활용하고자 한다.