• Journal of Korea Port Economic Association
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• v.32 no.2
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• pp.39-57
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• 2016

Many countries are developing transportation technologies aimed at reducing environmental pollution and the environmental burden. For example, environmentally friendly transportation routes and methods are being used to improve inland waterways in Europe. Against this backdrop, a case study was conducted on special cargo (weight cargo, earth and sand, etc.) on Korea's Gyeong-In Ara Waterway, an inland waterway connecting the Han River and the West Sea, serving a distribution function. The results of the analysis showed that coastal shipping could be promoted using the waterway, including a positive synergy among environmental, economic, and social aspects. That is, by shifting from overland transportation to marine transportation, it is possible to reduce environmental pollution, ease traffic congestion, decrease traffic accidents, and shorten the licensing period for the weight cargo demand of the northern area of the Han River. In this respect, the Gyeong-in Ara Waterway could become an environmentally friendly transportation route, promoting coastal shipping in Korea. However, for this to occur, support systems such as subsidies for marine transportation and using the inland waterway are required, as happens in the EU. Furthermore, existing policies to promote coastal shipping should be improved and applied more broadly.

• Korean Security Journal
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• no.14
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• pp.485-516
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• 2007

Jeju Special Self-Government Province adopted an autonomous police system for the first time since 60 years in Korean police. The purpose of autonomous police system is to offer a police service to be suitable in regional conditions. But Jeju autonomous police system for nearly one year after adoption is criticized to be established on the ground of political reason but not local decentralization. Actually Jeju autonomous police has not a clear cut jurisdiction and operation scope because of the jurisdiction duplication between national and autonomous police. The original task is confined on environment and sightseeing so on given to administration police for local self-government. So criminal investigation authority on general crimes is not to Jeuju autonomous police on account of special judicial police. First, it is the structural rationalization of Jeju autonomous police system. It speaks that Jeju provincial police bureau and police station have to be as national police institution, on the other hand, patrol district station and police box have to be as autonomous police institution. Of course, functional division has to be followed. National police performs managing all the assembly and demonstration by the management law on assembly and demonstration including the suppression against any large scale demonstration and disturbance, also the investigation on serious crimes just as international crimes and broaden area crimes including all the felony. Together national police performs the duty concerned to all the foreign affairs and national securities in along with the investigation on traffic accidents. On the other hand, autonomous police performs the function for citizen's life safety as crime prevention and the enforcement on the violation against police operation law, together the traffic management and the regulation on traffic violations. and the investigation on minor crime as simple violence or petty larceny including the management on local big events. Second, the budgetary of autonomous police is rationalized by the share of budgeting between Korean government and Jeju special self-government province. Third, urgent arrest authority on general crime and the rights of claims for the summary trial on minor crimes are given to autonomous police. Of course, this problem is resolved naturally in case of giving the investigation rights to autonomous police on minor crimes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5585-5593
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• 2014

This study tested the hypothesis that the significance of the heterogeneous dispersion parameter in safety performance function (SPF) used to estimate the expected crashes is affected by the endogenous heterogeneous prior distributions, and analyzed the impacts of the mis-specified dispersion parameter on the evaluation results for traffic safety countermeasures. In particular, this study simulated the Poisson means based on the heterogeneous dispersion parameters and estimated the SPFs using both the negative binomial (NB) model and the heterogeneous negative binomial (HNB) model for analyzing the impacts of the model mis-specification on the mean and dispersion functions in SPF. In addition, this study analyzed the characteristics of errors in the crash reduction factors (CRFs) obtained when the two models are used to estimate the posterior means and variances, which are essentially estimated through the estimated hyper-parameters in the heterogeneous prior distributions. The simulation study results showed that a mis-estimation on the heterogeneous dispersion parameters through the NB model does not affect the coefficient of the mean functions, but the variances of the prior distribution are seriously mis-estimated when the NB model is used to develop SPFs without considering the heterogeneity in dispersion. Consequently, when the NB model is used erroneously to estimate the prior distributions with heterogeneous dispersion parameters, the mis-estimated posterior mean can produce large errors in CRFs up to 120%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.1
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• pp.110-122
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• 1993

When voice is transmitted through packet switching network, there needs a overload control, that is, a control for the congestion which lasts short periods and occurrs in local extents. In this thesis, we analyzed the performance of the statistical packet voice multiplexer using the overload control strategy by bit dropping. We assume that the voice is coded accordng to (4,2) embedded ADPCM and that the voice packet is generated and transmitted according to the procedures in the CCITT recomendation G. 764. For the performance analysis, we must model the superposed packet arrival process to the multiplexer as exactly as possible. It is well known that interarrival times of the packets are highly correlated and for this reason MMPP is more suited for the modelling in the viewpoint of accuracy. Hence the packet arrival process in modeled as MMPP and the matrix geometric method is used for the performance analysis. Performance analysis is similar to the MMPP IG II queueing system. But the overload control makes the service time distribution G dependent on system status or queue length in the multiplexer. Through the performance analysis we derived the probability generating function for the queue length and using this we derived the mean and standard deviation of the queue length and waiting time. The numerical results are verified through the simulation and the results show that the values embedded in the departure times and that in the arbitrary times are almost the same. Results also show bit dropping reduces the mean and the variation of the queue length and those of the waiting time.

• The KIPS Transactions:PartA
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• v.13A no.7 s.104
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• pp.615-622
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• 2006

Caching in a Wireless Internet Proxy Server Cluster Environment has an effect that minimizes the time on the request and response of Internet traffic and Web user As a way to increase the hit ratio of cache, we can use a hash function to make the same request URLs to be assigned to the same cache server. The disadvantage of the hashing scheme is that client requests cannot be well-distributed to all cache servers so that the performance of the whole system can depend on only a few busy servers. In this paper, we propose an improved load balancing scheme using hashing and Round Robin scheme that distributes client requests evenly to cache servers. In the existing hashing scheme, if a hashing value for a request URL is calculated, the server number is statically fixed at compile time while in the proposed scheme it is dynamically fixed at run time using round robin method. We implemented the proposed scheme in a Wireless Internet Proxy Server Cluster Environment and performed experiments using 16 PCs. Experimental results show the even distribution of client requests and the 52% to 112% performance improvement compared to the existing hashing method.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.90-119
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• 2019

The purpose of this study is to investigate the significance of Buddhist stone art in the cultural zone of Mt. Bukhan. Mt. Bukhan witnessed the prevalence of Buddhist culture in and around it since the introduction of Korean Buddhism and served as the center of Buddhist culture in the nation, where new Buddhist temples continued to be built from the Three Kingdoms Period to the Joseon Period. Of the characteristics of its Buddhist culture, it is very noteworthy that the construction of military temples in and around it in the latter half of Joseon supported the function of Buddhist temples as basic places of worship. These military temples were closely related to the mountain's geopolitical location, traffic routes, and position in the national defense system-- its mountain fortress was an important defense facility. The stone art works of Mt. Bukhan can be categorized into various types, including stone stupas, stone pagodas, rock-carved Buddhas, stone Buddhas, towers and monuments (stone monuments), stone lanterns, flagpole supports, and rock-carved sarira pagodas. There are diverse types of stone art left on the mountain. As for its period characteristics, it is clear that the Buddhist art of Silla spread even to the Gyeonggi region, and that most of the works of stone art were created during the first half of Goryeo and the latter half of Joseon. Starting in Goryeo, the Buddhist temples of the mountain maintained close relations with the royal court by operating as the royal buddhist shrine for the royal family. In the latter part of Joseon, the construction of the Bukhan mountain fortress became the most important opportunity to produce stone art. As for the distribution of the stone artwork, it was usually created in the west part of the mountain from Unified Silla to the first half of Goryeo and in the southern and eastern parts of the mountain from the latter half of Goryeo to the latter half of Joseon. It is estimated that central Buddhist temples of the mountain changed due to Silla's military goal of advancing toward the west coast along the Han River in its early days and the construction of the Bukhan mountain fortress in the latter half of Joseon to protect the capital city. Finally, the stone art of Mt. Bukhan holds very high significance in art history because various types of stone art continued to be created on and around the mountain, the stone artwork of the mountain reflected representative styles for each period, and e rare and ofthe works produced on the mountain exemplified rare and unique styles.