• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.8 s.338
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• pp.15-26
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• 2005

In this paper, we propose an efficient $GF(2^m)$ multi-segment multiplier architecture and study its application to elliptic curve cryptography processors. The multi-segment based ECC datapath has a very small combinational multiplier to compute partial products, most of its internal data buses are word-sized, and it has only a single m bit multiplexer and a single m bit register. Hence, the resource requirements of the proposed ECC datapath can be minimized as the segment number increases and word-size is decreased. Hence, as compared to the ECC processor based on digit-serial multiplication, the proposed ECC datapath is more efficient in resource usage. The resource requirement of ECC Processor implementation depends not only on the number of basic hardware components but also on the complexity of interconnection among them. To show the realistic area efficiency of proposed ECC processors, we implemented both the ECC processors based on the proposed multi-segment multiplication and digit serial multiplication and compared their FPGA resource usages. The experimental results show that the Proposed multi-segment multiplication method allows to implement ECC coprocessors, requiring about half of FPGA resources as compared to digit serial multiplication.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.108-113
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• 2012

This study was conducted to evaluate soil nutrient concentrations and fertilizer recovery of sorghum- sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources. The treatments included livestock compost, alfalfa hay, oilcake, and chemical fertilizer. Nutrient applications were made at the rates equivalent to approximately 210 kg N per hectare. The oilcake and alfalfa materials had the lowest C : N ratio, but the livestock compost had the highest C:N ratio such as 33.7 : 1. The livestock compost resulted in the highest input to ground surface, which increased nutrient concentrations in soil. The oilcake and alfalfa materials with low C : N ratios increased N-mineralization rate in soil compared to livestock. The N uptake efficiency in plants treated by alfalfa or oilcake was approximately 60% of those treated with chemical fertilizer; but those with livestock compost had N uptake efficiency lower than 20%. The $P_2O_5$ uptake efficiency was the highest in the plants treated with the alfalfa hay, but the lowest in those with livestock compost. Recommendation of organic material selection should consider C:N ratio of the raw materials based on the individual crop requirement.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.14-25
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• 2006

Response of grain yield and milled-rice protein content to nitrogen (N) rates at various growth stages is critical for quantifying real-time and real-amount of applied N requirement for target grain yield and protein content. An experiment including 10 N rate treatments at transplanting, tillering and panicle initiation stages with four rice cultivars in 2003, 6 N treatments with two rice cultivars in 2004 and 2005 was conducted. Increase of N rates at PIS significantly increased both grain yield and milled-rice protein content but increase of N rates at tillering stage significantly increased grain yield but not milledrice protein content. Therefore, high grain yield and low milled-rice protein content would be difficult to obtain only by adjusting N rates at PIS. Internal N use efficiency (INUE) was 60.5 kg grain/kg N accumulation on an average over N treatments, cultivars, and experimental years, showing considerable reduction especially at high shoot N accumulation in the experimental year of low sunshine duration. Milled-rice protein content tended to increase almost linearly with increasing shoot N accumulation, but it revealed big variation even at the same shoot N accumulation at harvest. Milled-rice protein content decreased with increasing INUE. N accumulation in the milled rice increased at an almost constant proportion of 45.5 percent of the shoot N accumulated at harvest, showing slight decresing proportion with the increasing shoot N accumulation.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.55-65
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• 2002

The most representative fruit in Yanbian area is Applepear(Ping Guo Li). It has been a important resource of farm income. According to the economic growth and income Increase of individual consumers, food consumption pattern will be changed from grain to high value cash crops such as Applepear and vegetables. The globalization and adapt ion of free market oriented economic policy of China government have led to change the collective farming system to individual farm management system. The institutional transformation have brought about high productivity of farm products and incomes of farmers. Therefore the plantation area of Applepear and requirement of investment cost for establishment of Applepear farms have increased rapidly since the 1980's, the time of perestroika and glasnost in Chinese economy. In prosperity of Chinese agriculture, individual farmer's decision making as free selection of farmland use, selection of high pay-off crops, free sale of the products in free market and credit support for the project might be the most important factors. In case of Applepear farm development, net present value of the project net benefit was estimated at 55.518won per hectare and financial rate of return was 21%. The benefit/cost ratio of the project was 2.11. Considering 10% of discounting rate or the opportunity cost of capital in China the Applepear farm development project showed us economically feasible in the light of the above efficiency indices. The Chinese government has to support Applepear farm development project financially and institutionally considering the high-payoff benefit of the fruit and farmer's in come increase in the future.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.3
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• pp.8-16
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• 1999

This paper describes a VLSI design of Reed-Solomon(RS) decoder using the modified Euclid algorithm, with the main theme focused on the $\textit{GF}(2^8)$. To get area-efficient design, a number of new architectures have been devised with maximal register and Euclidean ALU unit sharing. One ALU is shared to replace 18 ALUs which computes an error locator polynomial and an error evaluation polynomial. Also, 18 registers are shared to replace 24 registers which stores coefficients of those polynomials. The validity and efficiency of the proposed architecture have been verified by simulation and by FLEX$^TM$ FPGA implementation in hardware description language VHDL. The proposed Reed-Solomon decoder, which has the capability of decoding RS(208,192,17) and RS(182,172,11) for Digital Versatile Disc(DVD), has been designed by using O.6$\mu\textrm{m}$ CMOS TLM Compass$^TM$ technology library, which contains totally 17k gates with a core area of 2.299$\times$2.284 (5.25$\textrm{mm}^2$). The chip can run at 20MHz while the DVD requirement is 3.74MHz.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.196-206
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• 2004

In the Next Generation Internet(NGI) backbone network, a Dense Wavelength Division Multiplexing (DWDM) technology has been more and more highlighted to cover the increasing subscribers and bandwidth requirement. For such a DWDM network, Routine and Wavelength Assignment (RWA) is the essential problem to establish the optimal path and assign a wavelength efficiently to the selected path in resource utilization. However, the existing RWA algorithms do not consider the congestion in the network so that the performance of then is so limited. To solve this problem, in this paper, we introduce a new RWA algorithm, called Multi Wavelength-Minimum Interference path Routing (MW-MIPR) that establishes a routing path to minimize the interference for many potential future connection setup request. And then, we also propose a wavelength-routed QoS routing scheme based on differentiated QoS classes with applying MW-MIPR algorithm. Simulation results are also given to prove the efficiency of the proposed algorithms.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.4
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• pp.167-176
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• 2017

There are increasing policies and safeguards to prevent various human resource losses with the development of automotive industry. Currently ISO26262 $1^{st}$ edition has been released in 2011 to ensure functional safety of electrical and electronic systems and the $2^{nd}$ edition will be released in the second half of 2016 as part of a trend. The E/E (Electrical & Electronics) system requirements verification is required through walk-through, 인스펙션, semi-formal verification and formal verification in ISO 26262. This paper describe the efficiency of model checking for the E/E system requirements verification by applying the product development project of ASIL (Automotive Safety Integrity Level) D for the electrical parking brake system.

• IE interfaces
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• v.25 no.3
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• pp.347-356
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• 2012

The acquisition cost of defense weapon system has been continuously increasing because of art-of-technology of it. This phenomenon requires efficiency and transparency in the weapon system acquisition process through cost estimation. Therefore cost estimation is very important to the government acquisition programs to support decisions about funding and to evaluate resource requirement as a key decision point. The Commercial parametric cost estimating models have been using extensively to obtain appropriate cost estimates in early acquisition phase. These models have many restrictions to ensure the cost estimating result in Korean defense environment because they are developed based on foreign R&D data. Also estimation results are different from Korean defense industry accounting system. So, some studies have been tried to develop a CER (Cost Estimation Relationship) based on the Korean historical data. However, there are some restrictions to improve the predictability and ensure the stability of the developed singular CERs which consider the following data characteristics individually. The the abnormal conditions of data that is multicollinearity, outlier and heteroscedasticity under rack of the number of observations. In this paper, a CER's Linear Combining Model is proposed to overcome those limitations which guarantee more accurate estimation (25.42% higher precision) than other singular CERs. At least, this study is meaningful as a first attempt to improve the predictability of CER with insufficient data. The methodology suggested in this study will be useful to develop a complex Korean version cost estimating model development in future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4A
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• pp.412-420
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• 2006

With the appearance of various types of traffic services in communication networks, a study on QoS(Quality of Service) packet scheduling mechanisms which can support differentiated service to each traffic service becomes very important. To meet this requirement, IEEE 802.11 Working Group established the IEEE 802.11e MAC protocol which categorizes every traffic services into 4 access categories(AC) and provides the differentiated service to each AC. In addition, the physical layer of IEEE 802.11a/g standards provide up to 54 Mbps transmission rate per one wireless LAN terminal. However, since the radio resource is hardly limited in wireless channel, it is necessary to find an efficient packet scheduling scheme to maximize the transmission efficiency. Therefore, in this paper, we proposed a new packet scheduling scheme that can enhance the total throughput by setting different contention windows(CW) of CSMA-CA channel access scheme to each wireless LAN terminal according its current channel states. Numerical results derived from using NS-2 network simulator have shown that our proposed packet scheduling scheme can enhance the performance of IEEE 802.11e more and more.

• Resources Recycling
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• v.22 no.3
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• pp.73-80
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• 2013

Metal prices are rapidly rising due to increasing demand of metals and limited available resources according to the industrial requirement. As a result, securing a stable supply of these metal resources has been recognized as a core element of national competitiveness and sustained economic growth. In the case of magnesium and its alloys which are entirely depending on import, low-grade magnesium scraps from end-of-life vehicles and 3C(Camera, Computer, Communication) parts and magnesium wastes such as sludge and dross generated during melting process are hardly recycled. Accordingly, the development and commercialization of recycling technology of low-grade magnesium scrap is desperately needed to improve efficiency of resource circulation and to establish the required proprietary of resource metal supply and demand. In this study, papers and patents on recycling technologies of waste magnesium were analyzed. The range of search was limited in the open patents of USA (US), European Union (EP), Japan (JP), Korea (KR) and SCI journals from 1974 to 2012. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies.