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      • KCI등재

        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.

      • KCI등재

        국부 구조 분석과 장면 적응 사전을 이용한 초고해상도 알고리즘

        최익현(Ik Hyun Choi),임경원(Kyoung Won Lim),송병철(Byung Cheol Song) 대한전자공학회 2013 전자공학회논문지 Vol.50 No.4

        본 논문에서는 상호 보완 관계에 있는 초고해상도 기법과 선명도 증강 기법을 통합하여 전체적인 화질을 향상시키는 새로운 초고해상도 기법을 제안한다. 먼저 학습 과정을 통해 선명도 증강의 세기에 따라 다중의 사전을 구성하고, 고 해상도 영상을 합성할 때 영상의 국부 영역 특성에 따라 서로 다른 사전을 적응적으로 참조하도록 한다. 또한, 추가적인 후처리 과정을 통하여 저해상도 영상에 내재되어 있는 아티팩트가 초고해상도 처리에 의해 증폭되는 현상을 감소시켜 화질을 극대화한다. 모의실험 결과에 따르면 제안한 알고리즘은 객관적 화질 측면에서 비교 대상이 되는 알고리즘들에 비하여 우수함을 보였다. 특히, 영상의 선명도를 나타내는 CPBD 측면에서 bi-cubic 대비 0.3, Song 기법과 Fan 기법 대비 0.1 높게 나타났다. 또한, 주관적 화질 측면에서 영상의 질감 영역 및 경계 영역의 화질이 향상된 결과를 보이는 것을 확인하였다. 제한된 방법은 기존 방법 대비 17% 정도의 메모리만을 필요로 하므로 구현 관점에서도 장점이 있음을 알 수 있다. This paper proposes a new super-resolution algorithm where sharpness enhancement is merged in order to improve overall visual quality of up-scaled images. In the learning stage, multiple dictionaries are generated according to sharpness strength, and a proper dictionary among those dictionaries is selected to adapt to each patch in the inference stage. Also, additional post-processing suppresses boosting of artifacts in input low-resolution images during the inference stage. Experimental results that the proposed algorithm provides 0.3 higher CPBD than the bi-cubic and 0.1 higher CPBD than Song’s and Fan’s algorithms. Also, we can observe that the proposed algorithm shows better quality in textures and edges than the previous works. Finally, the proposed algorithm has a merit in terms of computational complexity because it requires the memory of only 17% in comparison with the previous work.

      • KCI등재

        국부 구조 분석과 장면 적응 사전을 이용한 초고해상도 알고리즘

        최익현,임경원,송병철,Choi, Ik Hyun,Lim, Kyoung Won,Song, Byung Cheol 대한전자공학회 2013 전자공학회논문지 Vol.50 No.6

        본 논문에서는 상호 보완 관계에 있는 초고해상도 기법과 선명도 증강 기법을 통합하여 전체적인 화질을 향상시키는 새로운 초고해상도 기법을 제안한다. 먼저 학습 과정을 통해 선명도 증강의 세기에 따라 다중의 사전을 구성하고, 고 해상도 영상을 합성할 때 영상의 국부 영역 특성에 따라 서로 다른 사전을 적응적으로 참조하도록 한다. 또한, 추가적인 후처리 과정을 통하여 저해상도 영상에 내재되어 있는 아티팩트가 초고해상도 처리에 의해 증폭되는 현상을 감소시켜 화질을 극대화한다. 모의실험 결과에 따르면 제안한 알고리즘은 객관적 화질 측면에서 비교 대상이 되는 알고리즘들에 비하여 우수함을 보였다. 특히, 영상의 선명도를 나타내는 CPBD 측면에서 bi-cubic 대비 0.3, Song 기법과 Fan 기법 대비 0.1 높게 나타났다. 또한, 주관적 화질 측면에서 영상의 질감 영역 및 경계 영역의 화질이 향상된 결과를 보이는 것을 확인하였다. 제한된 방법은 기존 방법 대비 17% 정도의 메모리만을 필요로 하므로 구현 관점에서도 장점이 있음을 알 수 있다. This paper proposes a new super-resolution algorithm where sharpness enhancement is merged in order to improve overall visual quality of up-scaled images. In the learning stage, multiple dictionaries are generated according to sharpness strength, and a proper dictionary among those dictionaries is selected to adapt to each patch in the inference stage. Also, additional post-processing suppresses boosting of artifacts in input low-resolution images during the inference stage. Experimental results that the proposed algorithm provides 0.3 higher CPBD than the bi-cubic and 0.1 higher CPBD than Song's and Fan's algorithms. Also, we can observe that the proposed algorithm shows better quality in textures and edges than the previous works. Finally, the proposed algorithm has a merit in terms of computational complexity because it requires the memory of only 17% in comparison with the previous work.

      • KCI등재

        Chemical Constituents of the Culture Broth of Panus rudis

        Song, Ja-Gyeong,Ha, Lee Su,Ki, Dae-Won,Choi, Dae-Cheol,Lee, In-Kyoung,Yun, Bong-Sik The Korean Society of Mycology 2021 韓國菌學會誌 Vol.49 No.6

        In our ongoing search for new secondary metabolites from fungal strains, one novel compound (1) and nine known compounds (2-10) were isolated from the EtOAc-soluble layer of the culture broth of Panus rudis. The culture broth of P. rudis was extracted in acetone and fractionated by solvent partition; column chromatography using silica gel, Sephadex LH-20, and Sephadex G-10; MPLC; and HPLC. The structures of isolated compounds were elucidated by one- and two-dimensional NMR and LC-ESI-mass measurements. One new compound, panepoxydiol (1), and nine known compounds, (E)-3-(3-hydroxy-3-methylbut-1-en-1-yl)-7-oxabicyclo[4.1.0]hept-3-ene-2,5-diol (2), isopanepoxydone (3), neopanepoxydone (4), panepoxydone (5), panepophenanthrin (6), 4-hydroxy-2,2-dimethyl-6-methoxychromane (7), 6-hydroxy-2,2-dimethyl-3-chromen (8), 2,2-dimethyl-6-methoxychroman-4-one (9), 3,4-dihydroxy-2,2-dimethyl-6-methoxychromane (10), were isolated from the culture broth of P. rudis. This is the first report of isolation of a new compound panepoxydiol (1) and nine other chemical constituents (2-5, 7-10) from the culture broth of P. rudis.

      • Gene expression analysis based on de novo assembly in wheat RNA-sequencing

        Won Cheol Yim,KiTae Song,Byung-Moo Lee 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

        Wheat is the third largest crop in the world behind corn and rice. Wheat is grown over a wide range of environments, and an essential source of carbohydrates. However, the genomics of wheat, a non-model species, is still challenging despite of corn and rice was done. The recent advent of RNA-Sequencing, a massively parallel sequencing method for genome and transcriptome analysis, provides opportunity to identify gene discovery and molecular mechanisms of cellular processes. We performed a RNA-Seq experiment to find differentially expressed genes under high temperature condition. More than 344 million shot reads were generated using Illumina HiSeq technology. A comprehensive and integrated 285,324 transcripts were assembled via Trinity by combining tentative consensus sequences. Transcripts annotated by BLAST2Go and differently expressed transcripts were analyzed. A total of 208 up-regulated and 182 down-regulated transcripts were found that involve in plastid, starch and sucrose metabolism, glycerolipid metabolism and glycerolipid and dicarboxylate metabolism. Our results demonstrate that RNA-Seq can be successfully used for gene identification, transcript profiling in wheat. Furthermore these sequences will provide valuable resources for wheat researchers.

      • KCI등재

        The effectiveness of chemotherapy in breast cancer patients with brain metastases

        Won Cheol Chang(장원철),Yong Hwa Eom(엄용화),So Hee Lee(이소희),Byung Joo Chae(채병주),Byung Joo Song(송병주),Sang Seol Jung(정상설) 대한종양외과학회 2014 Korean Journal of Clinical Oncology Vol.10 No.2

        Purpose: Treatments of brain metastases in breast cancer include whole brain radiotherapy, surgery, stereotactic radiosurgery, and systemic chemotherapy. The aim of this study was to investigate the clinicopathological factors which were associated with brain metastases-related survival, and to evaluate the efficacy of systemic chemotherapy. Methods: A total of 106 breast cancer patients with brain metastases who were treated at the Seoul St. Mary’s Hospital were retrospectively analyzed. The brain metastases-free survival (BMFS) was defined as the time from first systemic metastases to detection of the brain metastases. Overall survival after brain metastases (OS) was measured from the detection of the brain metastases to death. The patient’s clinicopathological factors which were associated with BMFS and OS and role of systemic chemotherapy on brain metastases were evaluated. Results: The median BMFS was 30.7 months. In univariate analyses, age >50 years, stages I/II, tumor size <5 cm, positive lymph node ≤3, no vascular invasion, positive estrogen receptor, use of adjuvant chemotherapy, solitary brain lesion, and brain metastases as an initial recurrence site were associated with longer BMFS. The median OS after brain metastases was 5.0 months. In univariate analyses, nuclear grade I/II, mitotic activity indices <10, non-triple negative receptor, solitary brain lesion, and administration of local and systemic treatment on brain metastases were associated with longer OS. In multivariate analyses, systemic chemotherapy after brain metastases was the only significant prognostic factor associated with better OS and was effective regardless of blood-brain barrier (BBB) permeability. Conclusion: A systemic chemotherapy after brain metastases improved OS regardless of BBB permeability in breast cancer patients.

      • Broadband dual phase energy harvester: Vibration and magnetic field

        Song, Hyun-Cheol,Kumar, Prashant,Sriramdas, Rammohan,Lee, Hyeon,Sharpes, Nathan,Kang, Min-Gyu,Maurya, Deepam,Sanghadasa, Mohan,Kang, Hyung-Won,Ryu, Jungho,Reynolds Jr., William T.,Priya Jr., Shashank Elsevier 2018 APPLIED ENERGY Vol.225 No.-

        <P><B>Abstract</B></P> <P>Broadband mechanical energy harvesting implies stable output power over a wide range of source frequency. Here we present a cost-effective solution towards achieving broadband response by designing a magnetically coupled piezoelectric energy harvester array that exhibits a large power density of 243 μW/cm<SUP>3</SUP> g<SUP>2</SUP> at natural frequency and bandwidth of more than 30 Hz under 1 g acceleration. The magnetically coupled piezoelectric energy harvester array exhibits dual modes of energy harvesting, responding to both stray magnetic field as well as ambient vibrations, and is found to exhibit the output power density of 36.5 μW/cm<SUP>3</SUP> Oe<SUP>2</SUP> at 79.5 Hz under the ambient magnetic field while maintaining the broadband nature. The magnetically coupled piezoelectric energy harvester array was demonstrated to harvest continuous power from a rotary pump vibration, an automobile engine vibration and a parasitic magnetic field surrounding a cable of an electric kettle. These demonstrations suggest that the magnetically coupled piezoelectric energy harvester array could serve the role of a standalone power source for wireless sensor nodes and small electronic devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Magnetically coupled energy harvester array is demonstrated for broadband operation. </LI> <LI> Energy harvester provides dual mode energy harvesting in magnetic field and vibration. </LI> <LI> Energy harvester exhibits 243 μW/cm<SUP>3</SUP> g<SUP>2</SUP> power density and over 30 Hz bandwidth. </LI> <LI> Energy harvester is implemented in practical environments of a rotary pump, power cable, and car engine. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

      • Impact of the Crystalline Packing Structures on Charge Transport and Recombination via Alkyl Chain Tunability of DPP-Based Small Molecules in Bulk Heterojunction Solar Cells

        Song, Chang Eun,Kim, Yu Jin,Suranagi, Sanjaykumar R.,Kini, Gururaj P.,Park, Sangheon,Lee, Sang Kyu,Shin, Won Suk,Moon, Sang-Jin,Kang, In-Nam,Park, Chan Eon,Lee, Jong-Cheol American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.20

        <P>A series of small compound materials based on benzodithiophene (BDT) and diketopyrrolopyrrole (DPP) with three different alkyl side chains were synthesized and used for organic photovoltaics. These small compounds had different alkyl branches (i.e., 2-ethylhexyl (EH), 2-butyloctyl (BO), and 2-hexyldecyl (HD)) attached to DPP units. Thin films made of these compounds were characterized and their solar cell parameters were measured in order to systematically analyze influences of the different side chains of compounds on the film microstructure, molecular packing, and hence, charge-transport and recombination properties. The relatively shorter side chains in the small molecules enabled more ordered packing structures with higher crystallinities, which resulted in higher carrier mobilities and less recombination factors; the small molecule with the EH branches exhibited the best semiconducting properties with a power conversion efficiency of up to 5.54% in solar cell devices. Our study suggested that tuning the alkyl chain length of semiconducting molecules is a powerful strategy for achieving high performance of organic photovoltaics.</P>

      • Turtle mimetic soft robot with two swimming gaits

        Song, Sung-Hyuk,Kim, Min-Soo,Rodrigue, Hugo,Lee, Jang-Yeob,Shim, Jae-Eul,Kim, Min-Cheol,Chu, Won-Shik,Ahn, Sung-Hoon IOP Publishing 2016 Bioinspiration & biomimetics Vol.11 No.3

        <P>This paper presents a biomimetic turtle flipper actuator consisting of a shape memory alloy composite structure for implementation in a turtle-inspired autonomous underwater vehicle. Based on the analysis of the Chelonia mydas, the flipper actuator was divided into three segments containing a scaffold structure fabricated using a 3D printer. According to the filament stacking sequence of the scaffold structure in the actuator, different actuating motions can be realized and three different types of scaffold structures were proposed to replicate the motion of the different segments of the flipper of the Chelonia mydas. This flipper actuator can mimic the continuous deformation of the forelimb of Chelonia mydas which could not be realized in previous motor based robot. This actuator can also produce two distinct motions that correspond to the two different swimming gaits of the Chelonia mydas, which are the routine and vigorous swimming gaits, by changing the applied current sequence of the SMA wires embedded in the flipper actuator. The generated thrust and the swimming efficiency in each swimming gait of the flipper actuator were measured and the results show that the vigorous gait has a higher thrust but a relatively lower swimming efficiency than the routine gait. The flipper actuator was implemented in a biomimetic turtle robot, and its average swimming speed in the routine and vigorous gaits were measured with the vigorous gait being capable of reaching a maximum speed of 11.5 mm s(-1).</P>

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