3분과 : 가선집재작업에서의 작업 생산성 및 비용 분석

한원성 ( Won Sung Han ),한한섭 ( Han Sup Han ),김남훈 ( Nam Hun Kim ),차두송 ( Du Song Chu ),조구현 ( Koo Hyun Cho ),민도홍 ( Do Hong Min ),권기철 ( Ki Cheol Kwon ) 한국임학회 2014 한국산림과학회지 Vol.103 No.1

본 연구에서는 임목수확작업에 사용되는 집재기계의 작업효율성을 분석하여 경사가 급한(20° 이상) 작업조건에 적합한 가선계 집재기계를 선정하는데 기초 정보를 제공하고자, 타워야더(RME-300T), 트랙터부착형 집재기(일명: 춘천집재기), 트랙터윈치(FARMI) 등에 의한 집재작업에서의 작업생산성 및 비용을 비교 분석하였다. 평균 흉고직경이 20 cm, 집재거리 60 m, 가로집재거리 10 m, 그리고 기계이용률이 70%인 동일한 작업 조건에서 작업이 이루어질 경우, 타워야더의 1일 집재작업 생산성은 33.04 m3/일, 트랙터부착형 집재기는 38.47 m3/일, 그리고 트랙터윈치는 14.17 m3/일으로 분석되었으며, 이에 따른 집재작업비용은 각각 25,105원/m3, 20,520원/m3, 37,835원/m3으로 나타났다. 동일한 작업조건에서 집재거리에 따른 각 집재기계별 작업효율성을 비교하였을 경우, 집재거리가 40 m 이내로 짧을 경우에는 트랙터윈치에 의한 집재작업이 효율적이며, 40~140 m의 집재거리에서는 춘천집재기가, 140 m 이상의 장거리 집재작업에서는 타워야더가 가장 효율적인 것으로 나타났다. This study was conducted to provide field-based harvesting study information which can be used to select an optimal cable system for certain work conditions on steep grounds (>20° ground slope) in Korea. Toaccomplish this study objectives, we evaluated three cable yarding systems (RME-300T tower-yarder, Chuncheontower-yarder, FARMI tractor winch) working in typical work conditions for their yarding productivity and operational efficiency. Those yarders are commonly used for removing logs or trees on steep grounds in Korea. Under the same work conditions (average DBH of tree to be cut, 20 cm; yarding distance, 60 m; lateral yardingdistance, 10 m; and machine utilization rate, 70%), the average productivities were 33.04 m3/day, 38.47 m3/day, and 14.17 m3/day for RME-300T, Chuncheon tower-yarder, and FARMI, respectively. Our standardized cost comparison study also showed that the yarding cost was highest at 37,835 won/m3 with FARMI, followed byRME-300T at 25,105 won/m3 for the same work conditions. We found the lowest yarding cost with the Chuncheon tower-yarder at 20,520 won/m3 which was resulted primarily from high yarding productivity at theyarding distance (60 m). Our analysis suggested that a small machine such as FARMI could be a low-costyarding machine option for a cable yarding job with a short yarding distance (40 m or less). The Chuncheontower-yarder is well suited for a mid-range yarding distance job in Korea, ranged between 40 to 140 m. Ifyarding distance were longer than 140 m, the RME-300T tower yarder appears to be most cost-effective.

P247 : A study on use of complementary and alternative medicine for acne

( Sook Kyung Lee ),( Taek Geun Lee ),( Hyun Hwang Bo ),( Tae Gwang Kwon ),( Se Won Jung ),( Young Seok Lee ) 대한피부과학회 2013 대한피부과학회 학술발표대회집 Vol.65 No.2

Background: Complementary and alternative medicine (CAM) is any practice that has healing effects, but is not based on evidence demonstrated by scientific method. Recently, CAM has been used in various diseases including acne. However, there have been no studies on CAM for acne in Korea. Objectives: The purpose of this study was to analyze the use of CAM in acne patients. Methods: A total of 159 patients with acne were enrolled on the study, and filled out a questionnaire about use of CAM. Results: Overall 87.4% (139/159) of the patients reported the previous or current use of at least one more type of CAM. Cosmetics for acne (100, 22.9%) was most frequently used, followed by diet therapy (81, 18.5%), spa and bath therapies (77, 17.6%), health food supplement (67, 15.3%), skin care shop (64, 14.6%), oriental medicine (38, 8.7%), and aromatherapy (9, 2.1%). The most common reason for using CAM was ``wish to try everything`` (28.6%), and the most common source of information was internet (40.5%). The therapeutic effect of CAM was best with diet therapy (32.1%). The most common side effect of CAM was aggravation of symptoms. The most common monthly cost for CAM was between 50,000 and 100,000 won/person. Conclusion: As our results, we can predict that the use of various types of CAM for acne will become more common. Therefore, dermatologists need to study about benefits and adverse effects of CAM for acne.

부산.경남지역의 일부 고등학교 교사들의 물리치료에 대한 인식도 조사

김지원,박상현,주성희,김용권,안덕현,Kim, JI-Won,Park, Sang-Hyeon,Joo, Sung-Hui,Kim, Yong-Kwon,Ahn, Duck-Hyun 대한물리치료과학회 2003 대한물리치료과학회지 Vol.10 No.2

This study randomly chose 10 humanity high schools, which are located in Busan and KyoungNam province. We then examined the recognition rate of physical therapy among 378 teachers who were and still are working in the schools. 1. The recognition grade of physical therapeutics between men and women was significantly different with results of 80.7% of men and 69.7% of women(p<0.05). In the case of experiencing physical therapy, 83.6% of people said they knew the physical therapeutics and in the case of the opposite side, the result was also significantly different with a result of 67.8%(p<0.05). 2. We ranked the people on how much they knew about the physical therapeutics among men and women. With men, the actual experience of physical therapeutic came before what they heard from other people. In the case of women, what they heard from other people came first and the actual experience of physical therapeutic came after. According to the public information from Inje University, the recognition grade is recorded in the 3rd grade department as 21.5% while in the case of experiencing treatment from a physical therapist, the result was 39.1%. In the other department (the 1st grade department), what men and women heard from mass media was recorded at 17.5% and what they heard from other people, it was recorded at 33.8%(p<0.05). 3. The research about the recognition of academic ability of being a physical therapist was that 55.6% of teachers thought that 3-year-college was the best, which made the results different from the recognition grade of the experience of education(p<0.05). 4. In the recognition grade of physical therapeutics, there were significantly differences from 50.2% of men and 45.2% of women were expecting about 1mil ion won to 1.99million won. In case of 25.2% of people who have experience less than 15years at work, they expected about 2million to 2.99million won. The figures were higher than 10.1% of people who have experiences over 15years. About the recognition grade of physical therapists social level in the future is 48.8% of people who had experienced of physical therapy and 63.8% of people who never had experienced of it said it would be better in the future. From these results, the recognition about physical therapeutics and the view of its social status are optimistic and they know well about the level of academic ability of physical therapists. On the other hand, most teachers don't know exactly about physical therapists work. So we have to inform them aggressively for enhancing the recognition of physical therapy because high school students are well affected by their teachers when they face their future or major in university.

우황청심원 관련 최근 연구 동향 : 국내 논문에 대한 고찰

이제원,백경민,백영두,임은영,장우석,전우현,정인권,Lee, Je-Won,Baek, Kyung-Min,Baek, Young-Doo,Im, Eun-Young,Chang, Woo-Seok,Cheon, Woo-Hyun,Chung, In-Kwon 대한한방내과학회 2010 大韓韓方內科學會誌 Vol.31 No.4

Objectives : Woohwangchungsim-won has been used for acute diseases such as cerebrovascular disease (stroke), heart disease. The aim of this study was to determine the effects, significance & necessity of Woohwangchungsim-won in acute stages of these disease by reviewing Korean articles about Woohwangchungsim-won. Methods : Article searches were performed on 8 major Korean web article search engine from January 1980 to August 2010. There were no restrictions on the types of publication, including grey articles. Results : Forty-three articles were included. Twenty one were efficacy tests, thirteen were comparative efficacy tests, eight were toxicity tests, and one was new method development. Eighteen articles were multicenter studies and twenty five were single center studies. Thirty two articles were animal testing, only ten articles were clinical articles. Thirty seven articles presented the composition and quantity of Woohwangchungsim-won, but six did not. Conclusions : The results of Korean articles about Woohwangchungsim-won can not strongly support the effects, significance & necessity of Woohwangchungsim-won. More rigorous studies are required for determination of the effects of Woohwangchungsim-won.

High‐Performance Micro‐Solid Oxide Fuel Cells Fabricated on Nanoporous Anodic Aluminum Oxide Templates

Kwon, Chang‐,Woo,Son, Ji‐,Won,Lee, Jong‐,Ho,Kim, Hyun‐,Mi,Lee, Hae‐,Weon,Kim, Ki‐,Bum WILEY‐VCH Verlag 2011 Advanced functional materials Vol.21 No.6

<P><B>Abstract</B></P><P>Micro‐solid oxide fuel cells (<I>μ</I>‐SOFCs) are fabricated on nanoporous anodic aluminum oxide (AAO) templates with a cell structure composed of a 600‐nm‐thick AAO free‐standing membrane embedded on a Si substrate, sputter‐deposited Pt electrodes (cathode and anode) and an yttria‐stabilized zirconia (YSZ) electrolyte deposited by pulsed laser deposition (PLD). Initially, the open circuit voltages (OCVs) of the AAO‐supported <I>μ</I>‐SOFCs are in the range of 0.05 V to 0.78 V, which is much lower than the ideal value, depending on the average pore size of the AAO template and the thickness of the YSZ electrolyte. Transmission electron microscopy (TEM) analysis reveals the formation of pinholes in the electrolyte layer that originate from the porous nature of the underlying AAO membrane. In order to clog these pinholes, a 20‐nm thick Al<SUB>2</SUB>O<SUB>3</SUB> layer is deposited by atomic layer deposition (ALD) on top of the 300‐nm thick YSZ layer and another 600‐nm thick YSZ layer is deposited after removing the top intermittent Al<SUB>2</SUB>O<SUB>3</SUB> layer. Fuel cell devices fabricated in this way manifest OCVs of 1.02 V, and a maximum power density of 350 mW cm<SUP>−2</SUP> at 500 °C.</P>

<i>Zanthoxylum ailanthoides</i> Suppresses Oleic Acid-Induced Lipid Accumulation through an Activation of LKB1/AMPK Pathway in HepG2 Cells

Kwon, Eun-Bin,Kang, Myung-Ji,Kim, Soo-Yeon,Lee, Yong-Moon,Lee, Mi-Kyeong,Yuk, Heung Joo,Ryu, Hyung Won,Lee, Su Ui,Oh, Sei-Ryang,Moon, Dong-Oh,Lee, Hyun-Sun,Kim, Mun-Ock Hindawi 2018 Evidence-based Complementary and Alternative Medic Vol.2018 No.-

<P><I>Zanthoxylum ailanthoides</I> (ZA) has been used as folk medicines in East Asian and recently reported to have several bioactivity; however, the studies of ZA on the regulation of triacylglycerol (TG) biosynthesis have not been elucidated yet. In this study, we examined whether the methanol extract of ZA (ZA-M) could reduce oleic acid- (OA-) induced intracellular lipid accumulation and confirmed its mode of action in HepG2 cells. ZA-M was shown to promote the phosphorylation of AMPK and its upstream LKB1, followed by reduction of lipogenic gene expressions. As a result, treatment of ZA-M blocked de novo TG biosynthesis and subsequently mitigated intracellular neutral lipid accumulation in HepG2 cells. ZA-M also inhibited OA-induced production of reactive oxygen species (ROS) and TNF-<I>α</I>, suggesting that ZA-M possess the anti-inflammatory feature in fatty acid over accumulated condition. Taken together, these results suggest that ZA-M attenuates OA-induced lipid accumulation and inflammation through the activation of LKB1/AMPK signaling pathway in HepG2 cells.</P>

Performance improvement of gas turbine combined cycle power plant by dual cooling of the inlet air and turbine coolant using an absorption chiller

Kwon, Hyun Min,Kim, Tong Seop,Sohn, Jeong Lak,Kang, Do Won Elsevier 2018 ENERGY Vol.163 No.-

<P><B>Abstract</B></P> <P>A critical issue concerning the gas turbine is that its power decreases considerably with increasing ambient temperature. Recently, it was proposed to maximize the power output of gas turbines in hot seasons through the simultaneous cooling of inlet air and hot parts cooling air, using an absorption chiller. This study serves to expand this concept and applies simultaneous cooling to combined cycle power plants using an H-class engine, the latest gas turbine model. Two methods for coolant pre-cooling were comparatively investigated and the best option was selected. The proposed dual cooling was compared with other conventional cooling schemes and their combinations. These include simple inlet air cooling using a mechanical chiller or an absorption chiller, and the combination of each of these schemes with independent cooling of the coolant by ambient air. The maximum degrees of coolant pre-cooling and inlet air cooling using the largest capacity commercial absorption chiller were predicted to be 45 K and 11 K, respectively, and the power boost of the combined cycle plant was estimated to be 8.2%, which was larger than that obtained with any other scheme. An economic analysis confirmed the feasibility of the dual cooling scheme.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The impact of dual cooling in combined cycle power plants was analyzed. </LI> <LI> Inlet air and hot part coolant were cooled simultaneously by an absorption chiller. </LI> <LI> Power boost was predicted to be over 8% in an H-class gas turbine based power plant. </LI> <LI> The dual cooling showed a larger power boost effect than any other cooling scheme. </LI> <LI> Economic analysis demonstrated high feasibility of the dual cooling scheme. </LI> </UL> </P>

Synthesis and exothermic reactions of ultra-fine snowman-shaped particles with directly bonded Ni/Al interfaces

Kwon, Gu Hyun,Kim, Kyung Tae,Kim, Dong Won,Choe, Jungho,Yun, Jung Yeul,Kim, Jong-Man Elsevier BV * North-Holland 2019 Applied Surface Science Vol.476 No.-

<P><B>Abstract</B></P> <P>Nickel-nanoparticle-attached aluminum (Ni/Al) particles are synthesized by plating Ni onto Al particles with the surface oxide partly removed. The microstructure of the synthesized Ni/Al particles resembles a child’s snowman, with an approximately 200 nm spherical Ni nanoparticle bonded onto the surface of an Al particle about 800 nm in size. Particularly, the surface oxide is rarely observed at the Ni/Al interfaces unlike uncoated surface of the Al powder. Due to these microstructural characteristics, it was clearly noted that a self-propagating high-temperature synthesis (SHS) reaction of the snowman-shaped Ni/Al (SNA) particles occurs more actively compared to that which occurs when simply mixing particles of Ni and Al in the temperature range of 720–900 K. The formation of intermetallic compounds of NiAl or NiAl<SUB>3</SUB> is confirmed in a comparison of XPS results after both samples were oxidized at 773 K. The exothermic enthalpy energy, 8,850 Jg<SUP>−1</SUP> of SNA particles represents 118% of the value of 7,580 Jg<SUP>−1</SUP> for the mixed particles. These results indicate that SNA particles are promising as advanced reactive materials when used in conjunction with an efficient SHS reaction.</P> <P><B>Highlight</B></P> <P> <UL> <LI> Snowman-shaped Ni/Al particles are synthesized by removing Al oxide and plating Ni. </LI> <LI> The Ni nanoparticle is only coated on the surface oxide removed region of Al surface. </LI> <LI> The SNA particle shows high exothermic enthalpy energy during thermal oxidation. </LI> <LI> The directly bonded Ni/Al interface produces a rapid and much intermetallic compounds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Shear Cutting Theory for the Peripheral Edges of Brush Blades, and Tests of Its Effectiveness

Kwon, Young-Doo,Park, Sang-Jun,Choi, Won-Guk,Bang, Sang-In,Kwon, Hyun-Wook Korean Society for Precision Engineering 2014 International Journal of Precision Engineering and Vol.15 No.7

In this study, a shear cutting theory for wood or harsh brush is proposed, which can be applied to cases of usual supported cutting. Based on the proposed theory, a peripheral edge that takes full advantage of the proposed shear cutting theory is developed and tested for brush cutting. The new blade is composed of a conventional radial edge and the proposed peripheral edge. The peripheral edge cuts the brush in the first stage, and the radial edge cuts any remaining brush in the second stage. The decreases in cutting force and cutting energy due to the peripheral edge can be computed as a function of the shear angle for each given knife angle. A decrease in cutting energy signifies reduction in working time, gas consumption, and air pollution from a two-cycle engine, in which the lubrication oil is mixed directly with the fuel. The natural frequencies of the conventional and proposed blades are analyzed and the impact response of the peripheral edge, which is closely connected with the safety of the operator, is tested and compared with that of a conventional radial edge using the commercial software package.

A Power-Efficient Voltage Up-Converting Circuit System

Won-Ji Lee,Kyoung-Su Lee,Jong-Min Baek,Jung-Hyun Song,Jae-Chul Park,Kee-Won Kwon 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7

We developed a low-power voltage upconverter system that is composed of charge pump, level detector, and level shifter, which generates 1.0uA-10V from 2.5V VDD using 0.18um CMOS technology. The efficiency of the Dickson’s charge pump was analysed with respect to the size of pumping capacitors and the number of pumping stages, and the optimum condition was chosen from the analysis results. The level detector senses VPP voltage in capacitive division way in order to eliminate the steady state VPP power dissipation through the resistive voltage divider. The power consumption in level shifters is reduced without sacrificing the switching speed by inserting a bootstrapped p-MOSFET between cross-coupled p-MOSFET and pull down n-MOSFET. Combing the three techniques the power consumption of voltage up-converting circuit system is saved by 28%.