• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.81-86
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• 2013

This experiment was carried out to select white asparagus varieties suitable for shading culture in greenhouse. Eight white and one green varieties were tested. Seeds were sown in 72-cell trays in a glasshouse on 24 Dec. 2008 and the seedlings were transplanted in a P.E house on 22 May 2009. Planting distances were 30 cm apart in a raw and 125 cm between the raws. For white asparagus production, small tunnel ($210cm{\times}160cm$) was established inside the P.E house, and covered with black and white P.E film (0.1 mm) on 5 March 2010. Days to sprouting took 5 days in 'Ravel' variety and took 16 to 18 days in 'Backlim', 'Horlim', 'Herkolim' varieties. The number of spear was highest in 'Ravel' with 6 and lowest in 'Backlim' with 3.7. The spear weight was heaviest in 'Herkolim' with 25.6 g and lightest in 'Ravel' with 15.6 g. The highest total yield was in 'Herkolim' with 296 kg/10a, followed by 'Super welcome' with 275 kg/10a and lowest in 'Rapsody' with 176 kg/10a. Marketable yields in 'Super welcome' and 'Herkolim' were 241 kg/10a and 239 kg/10a, respectively, and the yield was lowest in 'Rapsody' with 139 kg/10a. The L grade (over 20 g of spear weight) was highest in 'Herkolim'. Accordingly, 'Herkolim' was the most suitable white asparagus variety among the tested varieties for shading cultivation in greenhouse.

• Journal of Mushroom
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• v.16 no.1
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• pp.57-60
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• 2018

Agricultural sticky traps are used for forecasting flying insects, including fungus gnat adults. Forecasting using sticky trap is an important measure to determine pesticides or environmentally friendly control means. Sticky traps of various colors can be installed easily and quickly. The yellow sticky trap is most effective for forecasting fungus gnat adults. In addition, they are used for control purposes by mass trapping. We tested the optimum installation height of yellow sticky traps to forecast and control the fungus gnat adults effectively in the cultivation of mushroom and horticultural plants. The number of captured fungus gnat adults was highest on the second floor for button mushroom and oyster mushroom, 100 cm above the floor for sawdust shiitake mushroom, 20 cm under the floor for hydroponic strawberry, and 20 cm above the floor for hydroponic tomato. This suggests that sticky trap height should be installed differently depending on the cultivation type or environment for effective forecasting and control of fungus gnat adults.

• Journal of Distribution Research
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• v.16 no.5
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• pp.1-18
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• 2011

Local assemblers of agricultural products perform important distribution functions such as providing sales outlets, labor forces, market information, and financing, forward contracting, farming, physical distribution, and etc. However, their business activities are not transparent and producers are not effectively protected from unfair practices done by local assemblers. In order to enhance transparency and to increase effectiveness of governmental policies, local assemblers, which are mostly private management, should be organized as corporations. In order to organize corporations, the government should emphasize the importance of education and should provide corporations with governmental funds for improvement of agricultural distribution. Corporations should be developed to marketing cooperatives in the long run, and are requested to form their federations. It is also necessary to have transparent forward contracting system by local assemblers. In order to have transparent system, producers and local assemblers are guided to use standard contract forms and to operate offices handling unfair trade practices by local assemblers. We also need a place to exchange forward contracts, which can be developed to a futures market in the long run. In summary, local assemblers of agricultural products, which are mostly private management, should be developed to corporations and be operated by a transparent manner in order to protect agricultural producers and increase efficiency of trading.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.104-104
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• 2011

2010년 기준 세계 물산업은 약 4,800억불 규모이며, 2025년에는 약 1조 달러 규모로 성장할 것으로 전망된다. 또한 기후변화 등의 요인으로 물산업의 범위는 물순환체계 전과정을 포괄하는 "유역종합개발+상하수도+대체수자원"으로 확장될 것으로 예측된다. 그러나 지금까지의 국내 물산업 육성은 주로 상하수도 분야 중심으로 국한되어, 기후변화에 대응한 유역종합개발 분야에 대한 시장 진출기회를 상실하고 있다. 상하수도 중심의 물산업은 이미 선진 메이저 기업들이 선점하여 치열한 경쟁이 벌어지고 있는 '레드오션'이라 할 수 있으므로, 새로운 물산업의 강국으로 부상하기 위해서는 우리가 가진 장점을 바탕으로 물산업의 새로운 영역을 개척하는 방안에 대한 연구가 필요한 시점이다. 본 연구는 먼저 국내외 물순환체계 전과정(유역종합개발+상하수도+대체수자원)에 대한 시장 조사을 통해 세계 물산업 시장을 프로젝트 유형별, 지역별로 분석하고, 이를 토대로 국내 물산업 육성과 해외진출을 위한 당면 과제를 다음과 같이 제시하였다. 첫째, 민관협력을 위한 제도적 틀을 형성할 필요가 있다. 정부의 역할이 매우 중요한데, 정부 또는 기금이 자금의 단순한 대부자에서 적극적인 투자자로 전환함으로서 국내 민간기업들의 해외시장 진입장벽을 낮추어 줄 필요가 있다. 정부 주도의 민관협력이 활성화되면 참여 기업의 재무적 리스크를 현저히 줄일 수 있다. 또한, 상하수도 운영 경험을 축적한 공기업이 해외진출 지원기능을 수행하도록 하여야 한다. 즉, 공기업이 민간 기업의 경쟁자가 아니라 지원자가 될 수 있도록 프레임을 바꿔주어야 한다. 둘째, 물산업 클러스터의 형성이다. 물산업 제조업은 대부분 중소 벤처기업으로 독자적인 해외진출이 곤란하므로, 물전문 공기업이 중소 벤처기업 육성 및 해외진출의 앵커 역할을 담당하는 것이 필요하다. 이스라엘이나 싱가포르의 물산업 클러스터처럼 Anchor 역할을 행하는 공기업과 민간기업이 장기적 협력관계를 구축할 수 있는 기반을 마련해야한다. 셋째, 신시장 역량의 창출이다. 기후변화로 크게 성장할 전망인 통합물관리 시장에 대한 전략적 접근이 요구된다. 우선 ODA 등 대외 원조자금을 활용하여 투자비가 적게 들고 정보를 선점할 수 있는 조사 설계부터 시작하여, 댐 및 수력개발, 상하수도 건설 운영 등에 단계적으로 접근할 수 있을 것이다. 또한, 향후 도입될 예정인 물인프라의 Smart 기술, 첨단 수처리 기술 등을 활용하여 새로운 시장을 개척해야 한다. 4대강살리기 사업, 해수담수화 등 조기에 경쟁우위를 갖출 수 있는 사업과 기술을 Flagship Project로 브랜드화하여 우리나라를 "물강국"으로 포지셔닝할 경우 세계 물시장 공략에 보다 효과적일 것으로 판단된다.

• Korean Journal of Materials Research
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• v.21 no.9
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• pp.497-501
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• 2011

The CdS thin film used as a window layer in the CdTe thin film solar cell transports photo-generated electrons to the front contact and forms a p-n junction with the CdTe layer. This is why the electrical, optical, and surface properties of the CdS thin film influence the efficiency of the CdTe thin film solar cell. When CdTe thin film solar cells are fabricated, a heat treatment is done to improve the qualities of the CdS thin films. Of the many types of heat treatments, the $CdCl_2$ heat treatment is most widely used because the grain size in CdS thin films increases and interdiffusion between the CdS and the CdTe layer is prevented by the heat treatment. To investigate the changes in the electrical, optical, and surface properties and the crystallinity of the CdS thin films due to heat treatment, CdS thin films were deposited on FTO/glass substrates by the rf magnetron sputtering technique, and then a $CdCl_2$ heat treatment was carried out. After the $CdCl_2$ heat treatment, the clustershaped grains in the CdS thin film increased in size and their boundaries became faint. XRD results show that the crystallinity improved and the crystalline size increased from 15 to 42 nm. The resistivity of the CdS single layer decreased from 3.87 to 0.26 ${\Omega}cm$, and the transmittance in the visible region increased from 64% to 74%.

• Korean Journal of Materials Research
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• v.27 no.10
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• pp.518-523
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• 2017

In commercial solar cells, the pattern of the front electrode is critical to effectively assemble the photo generated current. The power loss in solar cells caused by the front electrode was categorized as four types. First, losses due to the metallic resistance of the electrode. Second, losses due to the contact resistance of the electrode and emitter. Third, losses due to the emitter resistance when current flows through the emitter. Fourth, losses due to the shading effect of the front metal electrode, which has a high reflectance. In this paper, optimizing the number of finger on a $4{\times}4$ solar cell is demonstrated with known theory. We compared the short circuit current density and fill factor to evaluate the power loss from the front metal contact calculation result. By experiment, the short circuit current density($J_{sc}$), taken in each pattern as 37.61, 37.53, and $37.38mA/cm^2$ decreased as the number of fingers increased. The fill factor(FF), measured in each pattern as 0.7745, 0.7782 and 0.7843 increased as number of fingers increased. The results suggested that the efficiency(Eff) was measured in each pattern as 17.51, 17.81, and 17.84 %. Throughout this study, the short-circuit current densities($J_{sc}$) and fill factor(FF) varied according to the number of fingers in the front metal pattern. The effects on the efficiency of the two factors were also investigated.

• Journal of the Korean Vacuum Society
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• v.11 no.3
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• pp.176-182
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• 2002

Amorphous $TiO_2$ thin films were deposited on glass substrates by ion beam sputtering in which the ratio of $O_2$/Ar gas used as discharged gas was varied from 0 to 2. After optical and microstructure properties and chemical composition of thin films was analyzed, antireflection coating layers were fabricated with $SiO_2$/$TiO_2$ multi-layers. Thin films deposition was performed at room temperature and ion beam voltage and ion current density for sputtering of target were fixed at 1.2 kV and 200 $\mu\textrm{A}/\textrm{cm}^2$, respectively. Refractive indexs of the deposited $TiO_2$films were 2.40-2.45 at a wavelength of 633 nm. $TiO_2$films had high transmission and stoichiometry when ratio of $O_2$/Ar was 1. Rms roughness of deposited $TiO_2$ film was below 7 $\AA$. In excessive $O_2$ environments, however Rms roughness increased over 50 $\AA$. Transmittance decreased by scattering of rough surface. Reflectance of $SiO_2$/$TiO_2$multi-layers was below 1% in visible light.

• Research in Plant Disease
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• v.11 no.2
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• pp.115-121
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• 2005

This studies were carried out to elucidate the control effect of copper fungicides against some citrus diseases, assess copper spray injury on leaf and fruit of citrus by spraying of copper fungicides according to growth stages and spray seasons and by tank mixing with paraffin oil in field experiments for 3 years (2003-2005 season). As results, the control value was approximately $75\%$ against scab disease in all tested copper fungicides, $85-88\%$ to canker and $75-86\%$ to melanose. In case of leaf, the copper injury was the severest in early stage of shooting, and the injury was gradually weakened according to growth of leaf. In fruit, the copper injury was more severe in midsummer (late of July and August) than early of summer and spring season (June and ealy of July). Among copper fungicides, the bordeaux mixture which made by level of farm induced more injury compared to other copper fungicides commercialized. Less copper spray injury was observed on treatments in which copper fungicide was sprayed as tank mixtures with paraffin oil when compared to treatment which sprayed with only copper fungicide.

• Journal of Mushroom
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• v.11 no.4
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• pp.201-207
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• 2013

Fungus gnats are usually found in mushroom farm and have recently become important pest because they can cause severe damage and reduce the production on shiitake mushroom. Usually shiitake mushrooms are cultivated on both oak bed logs and in the artificial sawdust beds in greenhouses. Using yellow sticky trap, the dipteran species in shiitake mushroom farm were collected from May to September in Kyonggi-do and Chungcheong-do in 2013. To identify the main species of fungus gnat on the shiitake farm in Korea, the collected samples were determined the sequence of cytochrome c oxidase subunit I (COI) by DNA barcoding. The phylogeny based on maximum likelihood analyses from COI sequence showed that Bradysia difformis and B. alpicola were main species of shiitake bed log and Scatopsidae sp. and B. difformis were dominant species of sawdust beds.

• Journal of Mushroom
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• v.17 no.4
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• pp.255-260
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• 2019

The purpose of this study was to identify sector-wise issues that need to be improved for the overall development of the mushroom industry and to prioritize these tasks based on an analysis of the current state of this industry in Korea. To this end, we classified the domestic mushroom industry into four sectors: production, processing, marketing, and export and distribution, and identified major tasks for the improvement of each of these sectors. A total of eleven issues that could be improved were selected, including three each in the production, marketing, and export and distribution sectors, and two in the processing sector. An analytical hierarchy process (AHP) was utilized to identify the issues in each sector that would need to be handled on a priority basis. A questionnaire-based survey was also conducted to gain relevant insights and suggestions from 32 experts in this industry. The present study is significant because it highlights sector-wise priority areas that could be supported by policies and legal measures for the overall development of the mushroom industry.