• Journal of Mushroom
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• v.19 no.3
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• pp.184-190
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• 2021

With the development of sawdust medium cultivation technology, Lentinula edodes (shiitake mushroom) has become the most extensively produced and consumed mushroom globally. In this study, the approximate composition, nutritional components, and bioactive compounds of L. edodes were analyzed and compared for the five sawdust-cultivated shiitake mushrooms cultivars namely Sanjo701ho, Sanjo707ho, Sanjo715ho, Chamaram, and L808. The approximate range of the composition of freeze-dried shiitake mushrooms was 4.06-5.92 g/100 g of ash, 0.75-1.02 g/100 g of crude fat, and 21.24-29.15 g/100 g of crude protein. Sanjo701ho had the highest trehalose content (9.60±0.08 g/100 g), total polyphenol content (3.49±0.04 mg GAE/g), and total flavonoid content (1.33±0.03 mg QE/g) among the other shiitake mushroom cultivars. The total amino acid content was as follows: glutamic acid>aspartic acid>leucine. Glycine, alanine, valine, isoleucine, leucine, and phenylalanine contents were significantly decreased in the following sequence: Sanjo707ho, Sanjo715ho, Sanjo701ho, Chamaram, and L808. Crude protein, trehalose, and six types of amino acids were identified as classification indicators for the five cultivars of sawdust-cultivated shiitake mushrooms.

• KDI Journal of Economic Policy
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• v.25 no.2
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• pp.3-53
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• 2003

Using the plant level panel data on Korean manufacturing during 1990-98 period, this study tries to assess the role of entry and exit in enhancing aggregate productivity, both qualitatively and quantitatively. Main findings of this study are summarized as follows. First, plant entry and exit rates in Korean manufacturing seem quite high: they are higher than in the U.S. or several developing countries for which comparable studies exist. Second, in line with existing studies on other countries, plant turnovers reflect underlying productivity differential in Korean manufacturing, with the "shadow of death" effect as well as selection and learning effects all present. Third, plant entry and exit account for as much as 45 and 65 percent in manufacturing productivity growth during cyclical upturn and downturn, respectively. The findings of this study show that the entry and exit of plants has been an important source of productivity growth in Korean manufacturing. Plant birth and death are mainly a process of resource reallocation from plants with relatively low and declining productivity to a group of heterogeneous plants, some of which have the potential to become highly efficient in future. The most obvious lesson from this study is that it is important to establish policy or institutional environment where efficient businesses can succeed and inefficient businesses fail.

• KDI Journal of Economic Policy
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• v.20 no.3_4
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• pp.175-222
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• 1998

본 논문에서는 우리나라 국방예산 운영의 국민경제적 파급효과에 대한 실증분석에 기초하여 국방예산 규모논쟁에 대한 검토, 지출구조의 개선방안, 그리고 지출구조 개성을 위한 국방부문의 효율화 방향을 제시하였다. 실증분석을 위해 Feder-Ram 2부문-외부효과모형에 기초하여 1970년대 이후 총국방비 운영유지비 방위력개선비 등 3가지의 국방부문 지표를 이용한 실증분석 결과, 방위력개선비가 국민총생산에 대해 유의한 정(正)의 효과를 갖는 것으로 나타났다. 총국방비의 경우 유의성이 없었으며, 운영유지비의 경우 유의한 부(負)의 효과를 갖는 것으로 나타났다. 국방예산 규모논쟁과 관련하여, 최근 GDP 대비 국방비 비중과 안보위협을 고려한 국가군별 비교 등을 통해볼 때, 지금까지의 우리나라 국방비규모의 상대적 비중이 하락하는 추세를 더 이상 기대하기는 어렵다고 보는 것이 현실적인 인식이라고 판단된다. 이제 국방예산 관련 논의의 초점은 상대적 규모를 포함하여 국방예산규모 자체보다는 국방예산의 지출구조와 내역에 맞추어져야 하고, 국방예산 운영의 낭비사례를 방지하고 효율성 투명성을 높여서 적절한 지출구조와 배분내역 방식을 이루는 것이 되어야 한다고 판단된다. 국방예산 지출구조의 개선을 위해서 투자비 성격의 방위력개선비 비중을 높이는 예산구조상의 개선이 매우 중요한 과제이다. 이를 위해 각종 경사경비에 대한 영점기준의 검토작업과 더불어 인력과 장비의 대체, 인력구조의 조정 등을 통해 기술집약형 전력구조를 지향하는 보다 근본적인 구조조정노력이 이루어져야 할 것이다. 미래전 양상에 대비한 군 첨단화의 핵심인 해상방위력 및 항공력 증강 등이 필수적이며, 지상군 위주에서 상대적으로 해 공군 중심의 군 구조로 개선되어야 할 것이다. 구조개선의 완급조절과 군별배분의 수평적 구조개선을 통해서 예산규모의 커다란 증대 압력 없이 추진 할 수 있는 구조개선은 시급히 실현되어야 할 것이며, 구조조정 재원의 상당부분은 군 내부의 낭비사례를 막고 생산성을 획기적으로 제고해서 확보할 수 있어야 할 것이다. 국방예산 운영의 효율성 투명성 제고를 위해서는 군 내부 자원관리기능이 강화되어야 하고, 군조직 운영에 있어서도 민간부문에 상응하는 경영효율성 개념의 과감한 도입이 요구된다. 지금까지의 '국방전력 극대화'를 위한 군인중심의 획일적 폐쇄적 군조직 운영에서 벗어나 조직 인사 예산 운영 전반에 걸친 경영혁신이 이루어져야 한다. 국방부문에 경영효율성 개념을 도입하여 경영혁신을 이루어나가는 주요 정책방향은 일부 기능 조직의 민영화 및 민간위탁의 확대, 민간전문인력의 활용도 제고, 자율적 책임경이 필요한 부문을 대상으로 한 "책임경영사업소(Agency)제도"의 도입 등이다. 또한 유사기능을 갖는 조직과 각군별로 별도로 설립되어 중복되는 기능을 수행하는 기관을 통폐합해야 할 것이다.

• Journal of Legislation Research
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• no.44
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• pp.7-31
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• 2013

Paradigm of Global economy is changing to creative economy. This study focuses on the role of creative economy to clarify (understand clearly) the impact (influence) which transition of economy system will bring about. The creative economy is basically came from New economy theory. According to the New economy theory, a state can achieve sustainable growth without an inflation, or higher growth rate under given inflation rate, through an investment on ICT. However, different from America, Korea had limited effect of New Economy. This is because Korean economy had factor-input driven growth model rather than New Economy mechanism. However, ICT is essential requirement to move toward New Economy(Digital Economy), it does not sufficiently explain the increase of productivity and economic growth. A crucial point to realize New economy is how to diffuse and spill over the technology development on ICT sector to other industry. ICT is not creative industry or creative economy per se, and it should play as an enabler to improve other industry's productivity. The creative economy can be understood as an extension of New Economy theory. It means the economy that creates values by cultural assets and human resource, as well as capital and labor factors. However, if we understand the meaning of creative economy as change of input factors, it is hard to bring real shape of creative economy.

• Korean Journal of Optics and Photonics
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• v.32 no.4
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• pp.147-152
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• 2021

We report high-power continuous-wave operation of a Yb-doped fiber laser at 1070 nm, pumped by high-power laser diodes at 976 nm. Based on theoretical calculation of the stimulated Raman scattering and temperature distribution in the fiber, we construct a bidirectionally pumped Yb-fiberlaser system incorporating a pair of fiber Bragg gratings and a cladding light stripper. The fiber laser yields 3.0 kW of continuous-wave output at 1070 nm in a diffraction-limited beam with M² ≈ 1.26 for 4.1 kW of incident pump power, corresponding to a slope efficiency of 81.5%. The prospects for further power scaling are discussed.

• Korean Journal of Optics and Photonics
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• v.32 no.5
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• pp.209-214
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• 2021

High-power continuous-wave operation of a Yb-doped double-clad fiber laser at 1018 nm, pumped by high-power diode lasers at 976 nm, is reported. Based on numerical calculation of the gain and laser signal power along the length of the Yb fiber, it is found that robust operation at 1018 nm can be achieved for a high Yb³⁺-ion excitation density greater than 11.5%, accompanied by high suppression of the feedback from the fiber's end facet. The Yb fiber laser constructed in house yields 626 W of continuous-wave output at 1018 nm for 729 W of incident pump power, corresponding to a slope efficiency of 86.6%. The prospect for power scaling is considered.

• Smart Media Journal
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• v.12 no.10
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• pp.93-101
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• 2023

Climate change has emerged as a global problem, with frequent temperature increases, droughts, and floods, and it is predicted that it will have a great impact on the characteristics and productivity of crops. Cnidium officinale is used not only as traditionally used herbal medicines, but also as various industrial raw materials such as health functional foods, natural medicines, and living materials, but productivity is decreasing due to threats such as continuous crop damage and climate change. Therefore, this paper proposes a model that can predict the physiologically active ingredient index according to the climate change scenario of Cnidium officinale, a representative medicinal crop vulnerable to climate change. In this paper, data was first augmented using the CTGAN algorithm to solve the problem of data imbalance in the collection of environment information, physiological reactions, and physiological active ingredient information. Column Shape and Column Pair Trends were used to measure augmented data quality, and overall quality of 88% was achieved on average. In addition, five models RF, SVR, XGBoost, AdaBoost, and LightBGM were used to predict phenol and flavonoid content by dividing them into ground and underground using augmented data. As a result of model evaluation, the XGBoost model showed the best performance in predicting the physiological active ingredients of the sacrum, and it was confirmed to be about twice as accurate as the SVR model.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.5
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• pp.196-201
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• 2023

In order to improve the efficiency of the water splitting system for hydrogen energy production, the high overvoltage in the electrochemical reaction caused by the catalyst in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) must be reduced. Among them, transition metal-based compounds (hydroxide, sulfide, etc.) are attracting attention as catalyst materials to replace currently used precious metals such as platinum. In this study, Ni foam, an inexpensive metal porous material, was used as a support and β-Ni(OH)₂ microcrystals were synthesized through a hydrothermal synthesis process. In addition, changes in the crystal morphology, crystal structure, and water splitting characteristics of β-Ni(OH)₂ microcrystals synthesized by doping Fe to improve electrochemical properties were observed, and applicability as a catalyst in a commercial water electrolysis system was examined.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.80-86
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• 2024

This study was conducted to evaluate the potential of rape stalk (RAS) as a raw material for the production of solid bio-fuels. RAS was immersed in an aqueous solution with acetic acid concentration of 1 percent, The content of reducing sugars separated from the RAS was analyzed. Glucose showed the highest content followed by xylose, galactose, arabinose and mannose. The immersed and non-immersed RAS were used for producing pellets with a pilot-scaled flat-die pellet mill. Bulk density and calorific values of the pellets improved with the use of the immersed RAS and the addition of wood particles. The values exceeded the minimum requirements for the A-grade of non-woody pellets (≧600 kg/m³ & ≧ 14.5 MJ/kg) designated by the ISO. Ash content of the pellets reduced with the immersion of RAS and the value satisfied the A-grade level (≦6.0%) of the ISO standard. The durability of the immersed RAS-based pellets was much higher than that of non-immersed IRS-based pellets, and the values were increased with the addition of wood particles. However, the durability did not meet the acceptance level for the B-grade of non-woody pellets (≧96.0%) designated by the ISO. These results suggested that the addition of binders in the production of non-woody pellets using an RAS immersed in acetic acid-based aqueous solution is required for the commercialization of the pellets.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.110-118
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• 2021

This study was conducted to investigate the effects of species and varieties of summer forage crops on growth characteristics and productivity in Sihwa reclaimed land. The summer forage crops used in the trial were silage corn, sorghum×sudangrass hybrid(SSH), and proso millet. For each forage species, Gwangpyeongok(GPO), P15453, P1952 and P2088 were used for silage corn, and 877F, Green star, Honey chew, and Turbo gold cultivars were used for SSH. For proso millet, Ibaekchal, Geumsilchal and Manhongchal developed by the National Institute of Crop Science were used. Silage corn and SSH were sown on May 21, 2019 and proso millet on June 4, and harvested on September 2. There was no significant difference in plant and ear height of silage corn among varieties. P1543 was the highest and P2088 was the lowest in yield of silage corn, but there was no significant difference among treatments. Among the SSH, the plant height of 877F was the highest and Turbo gold variety had the smallest (p<0.05). As for the dry matter(DM) yields, 877F had the highest at 3,862 kg/ha and Green star had the lowest at 2,669 kg/ha (p<0.05). The fresh matter yield of proso millet was 15,778 kg/ha, which was higher than that of corn or SSH, The average dry matter yield was 4,780 kg/ha, and Ibaekchal variety had the highest DM yield compared to other varieties (p<0.05). P2088 had the highest TDN content and GPO was the lowest (p<0.05). As for the SSH, the TDN content of Green star and Honey chew varieties was significantly higher, and the RFV value was the lowest in Turbo gold. The average crude protein content of proso millet was 7.03%, and the highest TDN and RFV values were 64.36% and 106 in Geumsilchal. In the experiment of the germination rate of summer forage crops according to salt concentration, silage corn showed a germination rate of 83.1% even at 0.4% salinity. In particular, P2088 and P1921 varieties had more than 80% germination rate even at 0.6% salt concentration. As for the SSH, the germination rate of 877F was 93.3% even at 0.8% salinity, and 88.3% with Honey chew, indicating higher resistance to salt concentration compared to other varieties. Proso millet showed a high germination rate of 84.0 to 88.7% even at a salt concentration of 0.6%. Considering the above results, proso millet was recommended as the most suitable forage crop species in the Sihwa reclaimed land with high salt concentration, and the Ibaekchal variety is recommended as a suitable forage crop due to its high yield.