• Journal of Internet Computing and Services
• /
• v.7 no.5
• /
• pp.71-79
• /
• 2006

The GNUnet proposed a file encoding method by lKB block size to support anonymity of files and decentralizes encoded block to peers through unstructured model. but, the encoding and block decentralizing method with 600$\sim$700MB large multimedia file appeared two problems. First problem. it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructured model added network load by broadcasting decentralizing method. This paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation to 1% and network load by proposal structured model sending answer through dedicated peer to decentralize block.

• Journal of the Korea Concrete Institute
• /
• v.15 no.3
• /
• pp.497-503
• /
• 2003

Supplementary cementitious materials (SCM) such as fly ash, ground granulated blast furnace slag and silica fume are now being extensively used in concrete to control expansion due to alkali-silica reactivity (ASR). However, the replacement level of a single SCM needed to deleterious ASR expansion and cracking may create other problem and concerns. For example, incorporating silica fume at levels greater than 10％ by mass of cement may lead to dispersion and workability concerns, while fly ash can lead to poor strength development at early age, The combination of silica fume and fly ash in ternary cementitious system may alleviate this and other concerns, and result in a number of synergistic effects. The aim of the study was to enable evaluation of more realistic suitability of a silica fume-fly ash combination system for ASR resistance based on an in-house modification of ASTM C 1260 test method. The modification can be more closely identified with actual field conditions. In this study three different strengths of NaOH test solution(1N, 0.5N, and 0.25N) were used to measure the expansion characteristics of mortar bar made with a reactive aggregate. The other variable included longer testing period of 28 days instead of a conventional 14 days.

• Analytical Science and Technology
• /
• v.33 no.4
• /
• pp.197-207
• /
• 2020

The current comparison methods with scoring systems that are used to compare visualized latent fingerprints (LF) have disadvantages. Evaluators using these methods are prone to make errors and fail to discriminate LFs correctly to notice the differences among those LFs. Therefore, a comparative and quantitative evaluation method that is capable of obtaining more objective and quantitative results is needed. Densitometric image analysis (DIA) is used in other fields as a reliable semi-quantitative comparison method. To apply DIA to LFs, the potential variables that can occur during the DIA process were tested. The visualized ridges of LFs can be compared using the concentration of dots against the background to make it possible to analyze the ridges with DIA. The variables that can be present during the DIA process include the thickness of the analysis line, the number of ridges to be taken, the number of divided zones within each of the fingerprints, and the angles of the analysis line against the ridge lines that were selected. From the analysis of the inked fingerprints and circular lines that are similar to fingerprints, the angle of the analysis lines with the ridge line was the most significant variable. The preliminary test result was applied to the comparison of LFs that were developed with the powder method and then compared with the AFIS analysis. A similar trend was found, and a more detailed and semi-quantitative comparison of the visualized LFs was possible. In the future, it is necessary to check the evaluative ability of the DIA method by analyzing the visualized LFs with other various development methods. However, DIA is currently an option that can be used as an objective comparative evaluation method during fingerprint studies with supplementary role.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.20 no.43
• /
• pp.153-162
• /
• 1997

M/G/1 queueing system is one of the most widely used one to model the real system. When operating a real systems, since it often takes cost, some control policies that change the operation scheme are adopted. In particular, the N-policy is the most popular among many control policies. Almost all researches on queueing system are based on the assumption that the arrival rates of customers into the queueing system is constant, In this paper, we consider the M/G/1 queueing system whose arrival rate varies according to the servers status : idle, set-up and busy states. For this study, we construct the steady state equations of queue lengths by means of the supplementary variable method, and derive the PGF(probability generating function) of them. The L-S-T(Laplace Stieltjes transform) of waiting time and average waiting time are also presented. We also develop an algorithm to find the optimal N-value from which the server starts his set-up. An analysis on the performance measures to minimize total operation cost of queueing system is included. We finally investigate the behavior of system operation cost as the optimal N and arrival rate change by a numerical study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.81-90
• /
• 2006

The GNUnet proposed a file encoding method by 1KB block size to support anonimity of files, decentralizes encoded block to peers through unstructed mode and original data decoding method a block searching or encoded blocks. but, the encoding and block decentralizing method with $600\sim700MB$ large multimedia file appered two problems. First problem, it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructured model added network load by broadcasting decentralizing method. Third problem, The critical point of keyword search function. This paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation from 4% to 1%, network load by proposal structured model sending answer through dedicated peer to decentralize block and we defined content-based keyword and identifier of sharing file.

• The Journal of Engineering Research
• /
• v.7 no.1
• /
• pp.89-97
• /
• 2005

The GNUnet proposed a file encoding method by 1KB block size to support anonimity of file and decentralizes encoded block to peers through unstructed model. but, the encoding and block decentralizing method with 600~700MB large multimedia file appered two problems. First problem, it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructed model added network load by broadcasting decentralizing method. The paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation from 4% to 1%. and network load by proposal structured model sending answer through dedicated peer to decentralize block.

• Hwankyungkyoyuk
• /
• v.21 no.2
• /
• pp.80-88
• /
• 2008

As the gravity of the issue of the global warming surfaced, environmental protection and energy conservation have become one of the most serious issues that global society faces. At the status quo, there are criticisms for not effectively educating the students although the problem is very severe. In middle school, for instance, only 10% of the school offer environmental education while only $20{\sim}30%$ of the high school offer it. As witnessed by these examples, we can infer that there are not well-structured, effective environmental education for teenagers. Recently, NIE(Newspaper-In-Education) has been used as effective means for some fields of middle and/ or high school education. If so, it also could be used for environmental education. The researches, however, on the topic of NIE on environmental education are very rare. In this study, the effect of NIE on environmental education was empirically tested. Our basic assumption is that NIE will cause differences in environmental perception; the cognition and concern. And environment education through NIE will cause the high level of cognition, concern, and practice regarding environment issue. Using simple experimental design and regression analysis, we tested the effect of NIE on cognition, and, concern of environment issue, and then, on the practice of environment-improving action. The "cognition level" did not show significant difference between the experimental group(which was exposed to NIE) and control group(which was not exposed to NIE). The "concern level" for environment showed significant difference. Finally, the "practice level" showed highly significant difference between the experimental and the control group. According to regression analysis, "concern" and "NIE"(dummy variable) was turned out to be statistically significant variables for practice of environment improving action. Therefore, we came up with the conclusion that NIE, which provides the most up-to-date information regarding the environmental status, can serve as the good supplementary mechanism for the effective environment education in the present Korean middle school curriculum system. The statistical result also suggests that each individual school needs to employ and extend NIE method in its environment education curriculum.

• The Journal of the Korea Contents Association
• /
• v.9 no.5
• /
• pp.50-60
• /
• 2009

Recently, the traffic card is gradually utilized and its several supplementary services have been significantly developed. Particularly, since it is possible to pay fees for buses, taxies, subways, parking and tollgates with only one traffic card, new payment method for economically processing has been focused. This paper presents a new receipt management system which allows possibly paying with several digital cards through PC interfacing terminals. The proposed system is mainly composed of three parts: terminals, middleware, and management servers. A terminal part includes processing module for payment/charging and credit/check/debit cards, etc and its operation is fulfilled through a middleware part. A main task of a middleware part is to connect a terminal part to managing servers through middleware applications. Additionally, processing of several receipt items and monitoring of the terminals to product statistical reports based on the processed result are carried out in the middleware. A management sever part is accomplished for collecting all of transaction histories against users and charging items over allowed province and managing statistical information. The proposed system is currently utilized in the Nam-GU district office and the Nam-GU district health center, Busan, S. Korea, respectively for testing its effectiveness. We conclude from this demonstration that the system is more useful and efficient than the previous processing method especially in that variable payment ways are provided and consumption burden is reduced.

• Journal of the Korea Society for Simulation
• /
• v.24 no.3
• /
• pp.27-35
• /
• 2015

We analyze an M/G/1/K queueing system with queue-length dependent service and arrival rates. There are a single server and a buffer with finite capacity K including a customer in service. The customers are served by a first-come-first-service basis. We put two thresholds $L_1$ and $L_2$($${\geq_-}L_1$$ ) on the buffer. If the queue length at the service initiation epoch is less than the threshold $L_1$, the service time of customers follows $S_1$ with a mean of ${\mu}_1$ and the arrival of customers follows a Poisson process with a rate of ${\lambda}_1$. When the queue length at the service initiation epoch is equal to or greater than $L_1$ and less than $L_2$, the service time is changed to $S_2$ with a mean of $${\mu}_2{\geq_-}{\mu}_1$$. The arrival rate is still ${\lambda}_1$. Finally, if the queue length at the service initiation epoch is greater than $L_2$, the arrival rate of customers are also changed to a value of $${\lambda}_2({\leq_-}{\lambda}_1)$$ and the mean of the service times is ${\mu}_2$. By using the embedded Markov chain method, we derive queue length distribution at departure epochs. We also obtain the queue length distribution at an arbitrary time by the supplementary variable method. Finally, performance measures such as loss probability and mean waiting time are presented.

• Journal of Animal Environmental Science
• /
• v.10 no.2
• /
• pp.75-80
• /
• 2004

Field experiments were conducted in 2002 on sandy loam soil under variable fertilizer management; swine slurry and chemical fertilizer. The effect of different fertilizer management and application method on the growth characteristics and yield of rice were determined. The rice was planted to examine the effect of swine slurry on the crop growth. As slurry manure was fertilized, yield of each group of rice was decreased from 3 to $5\%$. In conclusion, basal application of slurry was maintained productivity of rice, but to improve of productivity of rice, the rice should be fertilized with the basal application of animal slurry and supplementary application of chemical fertilizer. The results indicates that application of animal slurry improves quality of rice rather quantity, which means grain yield. Rice quality of the slurry+chemical and the slurry were significantly better than that of the chemical fertilizer. That indicates application of animal slurry could improve rice quality. Application of animal slurry seemingly has potentials for reducing pollution of animal slurry and improving environment of rural area as well as producing high-quality rice.