중학생들의 인터넷 중독 위험수준에 따른 신체활동량과 비만도의 관련성

정민기(Jeong, Min-Ki),김권민(Kim, Gwon-Min),권유찬(Kwon, Yoo-Chan) 한국체육과학회 2015 한국체육과학회지 Vol.24 No.4

The purpose of this study was to examine the association perceived physical activity pattern and body mass index according to habitual internet usage among middle school student. Data were analyzed for 969 students who responded to self-reported base cross-sectional survey relating to socio-demographic variables, internet usage status, and a short version of the international physical activity questionnaire. Prevalence rate of physical activity status showed that 53.5% at 150 min/week under, 46.5% at 150min/week over. Prevalence rate of internet usage showed that 95.6% at normal group, 2.6% at potential group, 1,9% at addiction group. Prevalence rate of body mass index status of over weight according to internet usage status shoed that 83.1% at normal, 5.1% at potential, 11.9% at addiction. Prevalence rate of physical activity levels of 150 min/week under according to internet usage status showed that 93.8% at normal, 3.5% at potential, 2.7% at addiction. In comparison with the physical activity levels was significantly more likely potential internet usage (OR, 2.62; 95% confidence interval [95%CI], 1.09-6.47; p〈.05) and addiction usage (OR, 3.82; 95% confidence interval [95%CI], 1.24-11.75; p〈.05). The results revealed that physical activity levels and body mass index correlates of internet usage status. This finding suggest the necessity of developing specific strategies for physical activity intervention by internet addiction among middle school students.

Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

헬스케어용 가다랑어(Katsuwonus pelamis) 통조림의 제조 및 특성

김현정 ( Hyeon Jeong Kim ),김민지 ( Min Ji Kim ),김기현 ( Ki Hyun Kim ),지성준 ( Seung Jun Ji ),임경훈 ( Kyung Hun Lim ),박권현 ( Kwon Hyun Park ),신준호 ( Joon Ho Shin ),허민수 ( Min Soo Heu ),김진수 ( Jin Soo Kim ) 한국수산과학회 2012 한국수산과학회지 Vol.45 No.3

This study was conducted to prepare canned skipjack tuna Katsuwonus pelamis in the mixture of isotonic beverage and tomato paste (ST-S) for use as a health food. An analysis of the time-temperature profile and viable cells showed that a reasonable F0 value for ST-S preparation was 4 min. The proximate composition of ST-S was 76.8% moisture, 20.2% crude protein, 0.8% crude lipid, 1.7% ash and 0.5% carbohydrate. The calorie content of ST-S was 94.8 kcal, which is 47.4% lower than that of commercial canned skipjack tuna in oil (ST-O) and 2.2% lower than that of commercial chicken breast in water (CB-B). The total amino acid content of ST-S was 18.54 g/100 g, which is 31.4% lower than that of ST-O and 7.9% lower than that of CB-B. The major amino acids in ST-S were aspartic acid and glutamic acid. An enrichment effect due to such minerals as phosphorus, potassium and iron would be expected on consuming 100 g of ST-S. The major fatty acids in ST-S were 16:0 (27.4%), 18:1n-9 (14.3%) and 22:6n-3 (27.8%), which are different from those in ST-O and CB-B. The major free amino acids in ST-S were glutamic acid (8.1%), histidine (38.6%) and its related dipeptide, such as anserine (15.7%). In an evaluation of taste, flavor and color, ST-S was found to be superior to ST-O and CB-B.

스마트폰 사용정도가 수면의 질과 좌식행동에 미치는 영향

김권민(Kim, Gwon-Min),정민기(Jeong, Min-Ki),권유찬(Kwon, Yoo-Chan) 한국체육과학회 2016 한국체육과학회지 Vol.25 No.1

The purpose of this study was to examine the association perceived physical activity pattern and body mass index according to habitual internet usage among middle school student. Data were analyzed for 969 students who responded to self-reported base cross-sectional survey relating to socio-demographic variables, internet usage status, and a short version of the international physical activity questionnaire. Prevalence rate of physical activity status showed that 53.5% at 150 min/week under, 46.5% at 150min/week over. Prevalence rate of internet usage showed that 95.6% at normal group, 2.6% at potential group, 1.9% at addiction group. Prevalence rate of body mass index status of over weight according to internet usage status showed that 83.1% at normal, 5.1% at potential, 11.9% at addiction. Prevalence rate of physical activity levels of 150 min/week under according to internet usage status showed that 93.8% at normal, 3.5% at potential, 2.7% at addiction. In comparison with the physical activity levels was significantly more likely potential internet usage (OR, 2.62; 95% confidence interval [95%CI], 1.09-6.47; p<.05) and addiction usage (OR, 3.82; 95% confidence interval [95%CI], 1.24-11.75; p<.05). The results revealed that physical activity levels and body mass index correlates of internet usage status. This finding suggest the necessity of developing specific strategies for physical activity intervention by internet addiction among middle school students.

Improving the subcritical water extraction of flavonoids narirutin and hesperidin from Citrus unshiu peel by pulsed electric fields

Hui-Ju Kim,Mi-Ri Kwon,Hye-Ji Kang,Na-Yeon Kim,Hee-Jeong Hwang,Min-Jung Ko,Myong-Soo Chung 한국산업식품공학회 2017 학술대회 및 심포지엄 Vol.2017 No.11

Citrus fruit is important source of flavonoids, mainly flavanones which are narirutin and hesperidin. Those citrus flavonoids have been found to have health-related properties including antioxidant, anticancer, and anti-inflammatory. The main purpose of this study was to verify that the extraction of narirutin and hesperidin from Citrus peel can be more effective by combining pulsed electric field (PEF) pre-treatment and subcritical water extraction (SWE). Citrus unshiu peels were treated with PEF under conditions of electric field strength (3 kV/cm) and times (1 and 2 min). Subsequent SWE was conducted by using a Dionex Accelerated Solvent Extractor (ASE, Model 350) at extraction temperature 170°C for 10 min. The total flavonoids content was measured by using the aluminum chloride colorimetric method and the antioxidant capacity was analyzed by the Ferric reducing antioxidant power (FRAP) assay using spectrophotometer. The concentrations of narirutin and hesperidin were increased as PEF pre-treatment time increased. The highest concentrations of narirutin and hesperidin were 13.41 mg narirutin/g dry citrus peel and 141.16 mg hesperidin/g dry citrus peel at PEF pre-treatment condition of 3 kV/cm and 2 min. The total flavonoids contents of the extracts increased 105.2% and 123.1% for citrus peel PEF treated at 1 and 2 min, respectively. In addition, compared to the untreated sample, PEF pre-treatments of 1 and 2 min increased the antioxidant capacity of the extracts 109.2% and 160.8%, respectively. Therefore, the results demonstrate the potential of PEF pre-treatment to improve the SWE of flavonoids from citrus unshiu peel.

원산지별 감초추출물의 항산화활성 증가를 위한 효율적인 추출조건 탐색

하지훈 ( Ji Hoon Ha ),이혜미 ( Hye Mi Lee ),권순식 ( Soon Sik Kwon ),김해수 ( Hae Soo Kim ),김문진 ( Moon Jin Kim ),전소하 ( So Ha Jeon ),정유민 ( Yoo Min Jeong ),황준필 ( Jun Pil Hwang ),박종호 ( Jong-ho Park ),최영기 ( Yung-key 대한화장품학회 2013 대한화장품학회지 Vol.39 No.4

본 연구에서는 한국 및 중국산 감초(Glycyrrhiza uralensis), 그리고 우즈베키스탄산 감초(Glycyrrhiza glabra)를 대상으로 추출용매, 추출온도, 추출시간 등 추출조건별 추출물을 제조하고 이들 추출물들의 추출 수율과 항산화 활성을 비교하여 최적의 추출조건을 선정하였다. 항산화 활성 중 자유 라디칼(1,1-phenyl-2-pic-rylhydrazyl, DPPH) 소거활성은 85% 에탄올로 60 ℃에서 6 h 동안 추출한 조건에서 한국 감초로부터 얻은 추출물이 가장 높은 활성(46.05%)을 나타내었다. 루미놀 발광법을 이용한 추출물들의 총 항산화능 측정 실험과 피부 광노화에 중요한 ¹O₂으로 유도된 세포막 손상에 대한 추출물들의 세포 보호 효과를 측정한 실험 모두에서도 위의 조건에서 가장 높은 항산화 활성을 나타내었다. 특히, 한국 감초는 τ₅₀이 116.4 min으로 비교 물질인(+)-α-tocopherol (28.5 min)보다 약 4 배나 높은 세포 보호 효과를 나타내었으며, 추출 수율은 18.75%로 우즈베키스탄 및 중국 감초보다 각각 1.2 배 및 2.5 배의 추출 수율을 나타내었다. 따라서, 본 연구 결과는 항산화 소재로 화장품에 응용하기 위하여 감초로부터 추출물을 얻기 위한 최적의 조건은 85% 에탄올로 60 ℃에서 6시간 동안 추출하는 것임을 보여주었다. In this work, licorice extracts were prepared using various extraction conditions such as extraction solvent, temperature, and time from Glycyrrhiza uralensis (G. uralensis) produced in Korea and China and Glycyrrhiza glabra (G. glabra) in Uzbekistan. The optimum extraction condition was selected from the extraction yields and antioxidative activities of extracts. Korea licorice extracts showed the highest free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scav-enging activity (46.05%) under the extraction condition of 85% ethanol at 60 ℃ for 6 hours. The prominent ROS (reactive oxygen species) scavenging activity using luminol-dependent chemiluminescence assay and the cellular protective effect against ¹O₂ induced cellular membrane damage were also shown from the extracts obtained from the same condition. Especially, Korea G. uralensis extracts exhibited the higher prominent protective effect (τ₅₀ = 116.4 min) than (+)-α-tocopherol (τ₅₀ = 28.5 min) and the extraction yield of Korea licorice extract was 18.75%, which is 1.2 times and 2.5 times higher than that of Uzbekistan and China, respectively. These results indicate that the extraction condition of 85% ethanol at 60 ℃ for 6 hours is optimal to prepare licorice extracts, which can be applicable as antioxidative cosmetic materials.

雜種 自植系統을 利用한 벼의 RELP 遺傳子 地圖 作成

권오병,이정민,권무식 성균관대학교 생명과학자원연구소 1996 生命資源科學硏究 Vol.2 No.2

Numerous genetic studies have been focused on the elucidation of the structure of rice genome because of its economic importance in the world as well as its shortest genome size among monocots. Restriction fragment length polymorphism(RFLP) is a leading method to map a genome. It has been proven that recombinant inbred lines(RILs) provide an efficient way of mapping genetic markers. In this study, RFLPs of RILs of the rice were determined as follows. Some 164 F_11 individuals of RILs have been derived from F_2 populations of Milyang23 × Gihobyeo. Genomic DNAs were isolated from both the parents and RIL individuals. The DNAs were restricted by 8 different endonucleases (BamH I , Dra I , EcoR I , HindⅢ, EcoRⅤ, Xba I , Sca I , and Kpn I ). The restriction fragments were resolved on agarose gel(0.9%) for Southern blots. RFLP patterns of the parents and RIL individuals were determined using the cDNA clones of RZ & KCD, and the genomic clones of Pst I-digested RG as probes. The RFLP patterns and the linkage map of the genome were determined with the aid of a computer program, Macintosh Mapmaker 3.0. The map shows 125 genetic markers including 106 RFLP loci(4 KCD, 67 RG, and 35 RZ clones). This molecular map contains 1,196.8 centi-Morgan(cM) with average interval size of 9.57 cM on the framework map. This study could facilitate chromosome walking, map-based cloning, quantitative trait mapping, marker-assisted breeding, and evolutionary studies of the rice.

마이크로 그루브 가공의 특성 평가

권동희,박진효,김정석,김병민,정융호,강명창 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

As demands for micro parts are on the increase in recent industries such as aerospace, biomedical, electronics, environment, information technology and display, the need for manufacturing such parts is also increasing. Major methods of manufacturing micro parts are based on semiconductor process technology such as lithography and etching and non-traditional machining using lasers, ultrasonic, ion-beams or electrical discharge. However, these methods require lots of time, workpiece materials are limited, and such methods are only applicable to the machining of two-dimensional shapes. Therefore, mechanical machining methods are required for the manufacturing of micro parts with complex shapes. This paper presents an investigation on the characteristics for micro groove machining by using the ultrahigh-speed air turbine spindle, and verifies the properties of mechanical method in fabricating molds for micro barrier ribs. As a result, the optimal machining condition could be found from the investigation of surface roughness according to the kinds of burr shapes in the fabricating of iron mold by using micro endmill.

Effect of Forging Type on the Deformation Heterogeneities in Multi‑Axial Diagonal Forged AA1100

Min‑Seong Kim,Sang‑Chul Kwon,Sun‑Tae Kim,Seong Lee,Hyo‑Tae Jeong,Shi‑Hoon Choi 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3

The present study investigated the effects that different types of forging exert on the deformation heterogeneities developedin AA1100 during multi-axial diagonal forging. To measure the deformation heterogeneities of deformed workpieces, thevalues for hardness and Kernel average misorientation were measured at the center section following each forging process. Type-D forging that consists of diagonal forging and return-diagonal forging was relatively advantageous compared withType-P forging that includes plane forging and return-plane forging for minimizing the non-uniformity of deformationdeveloped in workpieces. The effective strain developed in a workpiece during the 2 types of forging was simulated using3-D FEA. FEA revealed that the positions and degrees of occurrence for soft and hard-zones in workpieces vary greatlydepending on the forging type. Type-D forging was relatively advantageous compared with Type-P forging for minimizingthe non-uniformity of effective strain developed in workpieces.

현대건축의 Context적 디자인방법에 관한 연구

권영민,윤정근 慶南專門大學 1997 論文集 Vol.25 No.1