• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.878-883
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• 2018

A circulating fluidized bed (CFB) has been used in various chemical industries because of good heat and mass transfer. In addition, the methanol to olefins (MTO) process requiring the CFB reactor has attracted a great deal of interest due to steep increase of oil price. To design a CFB reactor for MTO pilot process, therefore, we has examined the hydrodynamic properties of spherical catalysts with different particle size and developed a correlation equation to predict catalyst holdup in a riser of CFB reactor. The hydrodynamics of micro-spherical catalysts with average particle size of 53, 90 and 140 mm was evaluated in a $0.025m-ID{\times}4m-high$ CFB riser. We also developed a model described by a decay coefficient to predict solid hold-up distribution in the riser. The decay coefficient developed in this study could be expressed as a function of Froude number and dimensionless velocity ratio. This model could predict well the experimental data obtained from this work.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.484-486
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• 2022

대체 불가능한 토큰을 의미하는 NFT 는 블록 체인 기반 기술 중 하나로 소유권과 거래 이력이 블록 체인에 기록이 된다는 장점을 지녀 미술 작품 거래에도 활발히 활용되고 있다. 하지만 현재 NFT 작품 거래 시장은 주식거래와 같이 회전율과 거래량을 중점으로 투기성이 짙으며, 작품의 섬네일 이미지만으로 거래 의사를 판단하는 경우가 많다는 문제점이 대두되고 있다. 따라서 작품의 다양한 특성에 대한 고려가 함께 이루어질 필요가 있다. 본 논문은 작품의 다양한 변수를 수집하여 최적의 변수 조합을 찾아내고, 이미지 전이 학습과 생성 알고리즘을 활용해 다양한 변수가 가격에 미치는 영향을 알아보고자 했다. 연구 결과 이미지 만을 활용한 가격 예측은 정확도가 높지 않다는 사실을 확인하였고 작품이 가진 여러 특성을 변수로 한 정형 데이터의 가격 예측 정확도가 더 높은 것을 알 수 있었다. 또한 생성 알고리즘을 통해 새로운 특성 조합의 작품들을 만들었고 가격을 수치 예측해보았다. 이를 실제 작가의 작품의 가격과 가격의 변동 추이를 대조해 작가의 작품 판매 가격 평균치 이상인 작품의 특성을 확인할 수 있었다.

• Korea Trade Review
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• v.47 no.2
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• pp.133-154
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• 2022

The Baltic Capesize Index (BCI), which is used as an indicator for marine transportation of steel raw materials, is one of the key economic indexes for managing the risk of loss due to rapid market fluctuations when steel companies establish business strategies and procuring plans for raw materials. Still, the conditions of supply and demand of steel raw materials has been extremely affected by volatility shocks from drastic events like the financial crisis such as the Lehman Brothers incident and changes in the external environment such as COVID-19. And, especially since the 2008 financial crisis, endeavors to predict the market conditions of the steel raw material is becoming more and more arduous for the deepening uncertainty and increased volatility of BCI, which has been used as a leading indicator of the real economy. This study investigates the correlation between the steel raw material market and the marine transportation market by estimating the spillover effect of information between markets. The vector error correction model (VECM) was used to analyze information transfer based on the correlation between the BCI and crude steel production, capesize fleet supply, raw material price, and cargo volume.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.5
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• pp.11-20
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• 1999

The data transfer width between the mocroprocessor and the memory comes to a critical part that limits system performance since the data transfer width has been as it was while the performance of a microprocessor is getting higher due to its continuous development in speed. And it is important that the memory should be in small size for the reduction of embedded microprocessor's price which is integrated on a single chip with the memory and IO circuit. In this paper, a mocroprocessor tentatively named as Extendable Instruction Set Computer(EISC) is proposed as the high code density 32 bit mocroprocessor architecture. The 32 bit EISC has 16 general purpose registers and 16 bit fixed length instruction which has the short length offset and small immediate operand. By using and extend register and extend flag, the offset and immediate operand could be extended. The proposed 32 bit EISC is implemented with an FPGA and all of its functions have been tested and verified at 1.8432MHz. And the cross assembler, the cross C/C++ compiler and the instruction simulator of the 32 bit EISC shows 140-220% and 120-140% higher code density than RISC and CISC respectively, which is much higher than any other traditional architectures. As a consequence, the EISC is suitable for the next generation computer architecture since it requires less data transfer width compared to any other ones. And its lower memory requirement will embedded microprocessor more useful.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.73-80
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• 2007

As BTL(Build-Transfer-Lease) private investment business benchmarking PHI(Private Finance Initiative) of USA and Japan is introduces to Korea since 2005, as a part of supplying high leveled public service and early expanding required facilities for SOC, Value for Money on private investment business from treasury investment business at the beginning gets to be needed. Accordingly, this survey has been conducted in order to analyse BTL projects status, propriety of economic analysis method(VFM analysis, calculation of estimated business expenses, valuation of bidding price, etc.) by business advance phases from the viewpoint of person in charge, necessity of improvement and alternative plants. As the result of conducting cross tabulation analysis and correlation analysis by occupational group, BTL project advance phases and alternative plans for improvement, it is necessary ye prepare standardized service level against business expense and basis for calculating and evaluation operation expenses. Based on the necessity of quantitative analysis (LCC analysis) of VFM, standard for calculating management, maintenance and administration expenses is required. In addition, reliable economic valuation system considering domestic BTL environment should be setup, for business efficiency.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.221-236
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• 1993

Economic conditions of Korean agriculture have been aggravated since farmers experienced the shortage of labor, instability of farm product price, lack of capital and pressure of opening domestic market. Nevertheless, agriculture must be maintained because structure of national economy can not be progressed without balanced growth of food industry. So the problem that we must solve is to keep agriculture competitive. In that case technology is important in terms of improving productivity, overcoming labor shortage and stabilizing price. This paper is to study the technology adoption on the farm level, focusing on the theories of technology adoption, their empirical test and effect of technology adoption on the farm household income. In this study five theories-independent model, linear model, middle class conservation model, modified middle class conservation model, basic needs and wealfare model- were introduced concerning differentiated technology adoption rate by farmers' class. Based on the survey of controlled strawberry farming in Nonsan County, Chungnam Province, who adopted six kinds of technology, modified middle class conservation model was found to explain five kinds of technology adoption pattern and linear model was useful to explain one kind of technology, that is, irrigation method, These results may mean that controlled strawbary cultivators of middle class were reluctant to accept new technology. There are many variables to effect on the technology accepting rate, that is, farmer's age, labor capacity, education level, cultivation career, size of total cultivated land, and size of strawberry farming land. LOGIT model was used to find which variable influence the technology adoption rate. Results of estimation showed that variables of cultivation career and total land size, of which coefficients were statistically significant at the 5 percent level, might be main influential factors in accepting more than three farming techniques. There was a significant income difference between farm households accepting new methods and those rejecting them. Especially in case of low class of farming group, income of farmers who was adopting new technology was examined to be much higher than that of farmers who did not adopt. This result suggests that new technology play an important role in increasing farm household income. Finally this study emphasized that there is a need to develop proper measure of technology transfer considering various socioeconomic conditions of farm households.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.149-161
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• 2017

This paper analyzed the impact of alliances on the market value of the 106 bio-pharmaceutical companies listed on the KOSPI or KOSDAQ in Korea by using the 'Event study methodology'. Although general alliances did not impact the corporate value significantly, in the analysis corresponding to the alliance type, R&D alliances created positive value, as technology acts as an important factor for the alliance. Among the R&D alliances, 'Technology Transfer alliances', in particular 'Development Technology Transfer alliances', had a positive influence on the corporate value. We interpret these differentiated results as market tends to screen for types of alliances. Meanwhile, we confirmed that the possibility of a stock price increase before the alliance announcement is high by analyzing the impact of the timing of corporate alliance announcements on the company value. It can be inferred that the possibility of information leakage is high. This paper analyzes the impact of alliances for managers and practitioners seeking to create value for domestic bio-pharmaceutical companies, and suggests the need to prevent information leakages by establishing a suitable policy.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.4
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• pp.296-301
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• 2016

Using high magnetic flux from a 60 Hz high-current cable, a 2 W wireless-powered energy harvesting receiver for sensor operation, internet of things (IoT) devices, and LED lights inside electrical cable tunnels is proposed. The proposed receiver comprises a copper coil with a high number of turns, a ring-shaped ferromagnetic core, a capacitor for compensating for the impedance of the coil in series, and a rectifier with various types of loads, such as sensors, IoT devices, and LEDs. To achieve safe and easy installation around the power cable, the proposed ring-shaped receiver is designed to easily open or close using a clothespin-shaped handle, which is made of highly-insulated plastic. Laminated silicon steel plates are assembled and used as the core because of their mechanical robustness and high saturation flux density characteristic, in which the thickness of each isolated plate is 0.3 mm. The series-connected resonant capacitor, which is appropriate for low-voltage applications, is used together with the proposed receiver coil. The concept of the figure of merit, which is the product weight and cost of both the silicon steel plate and the copper wire, is used for an optimized design; therefore, the weight of the fabricated receiver and the price of raw material is 750 gf and USD $2 each, respectively. The 2.2 W powering capability of the fabricated receiver was experimentally verified with a power cable current of $100A_{rms}$ at 60Hz.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.930-934
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• 2013

The growth performance of embryo-transferred Japanese Black calves that were born from, and suckled by, Japanese Shorthorn cows in a cow-calf grazing system (BS-group, n = 5) was compared to that of Japanese Black calves from Japanese Black cows in a cowshed (BB-group, n = 5). The daily weight gain from birth to 1 month was higher in the BS-group than in the BB-group (p<0.01), and the same trend (p<0.05) was observed at 2 and 3 months of age. This resulted in body weight that was significantly higher for the BS-group between 1 and 3 months of age than what was observed for the BB-group (p<0.05). Heart girth was significantly greater in the BS-group than in the BB-group throughout the experimental period (p<0.01), and chest depth and withers height in the BS-group were significantly greater from 2 to 4 months of age (p<0.05) and at 4 months of age only (p<0.05). No difference in body length (p>0.05) was observed between the groups. These results suggest that the maternal effect of Japanese Shorthorn cows was positive for embryo-transferred Japanese Black calf growth during the early suckling stage. As Japanese Black calves are traded at a high price on the Japanese market, we conclude that this proposed production system is likely to improve the profitability of herd management in upland Japan.

• The KIPS Transactions:PartA
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• v.10A no.6
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• pp.635-642
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• 2003

The radical development of recent network technology provides the basic foundation which can establish a high speed and cheap cluster system. It is a general trend that conventional cluster systems are built as the system over a fixed level based on stabilized and high speed local networks. A multi-distributed web cluster group is a web cluster model which can obtain high performance, high efficiency and high availability through mutual cooperative works between effective job division and system nodes through parallel performance of a given work and shared memory of SC-Server with low price and low speed system nodes on networks. For this, multi-distributed web cluster group builds a sub-cluster group bound with single imaginary networks of multiple system nodes and uses the web distributed shared memory of system nodes for the effective data transmission within sub-cluster groups. Since the presented model uses a load balancing and parallel computing method of large-scale work required from users, it can maximize the processing efficiency.