• Herbal Formula Science
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• v.17 no.2
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• pp.65-72
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• 2009

Objectives : Yukmijihwang-tang (YJT) is known as a tonifying formula for reinforcement of yin deficiency conditions. The present study was carried out to investigate the potential acute toxicity of YJT in ICR male and female mice. Methods : We investigated the acute toxicity about boiling water-extracted YJT. The test article was orally administered once by gavage to 20 male and 20 female mice at dose levels of 0 (control group), 1250, 2500 and 5000 mg/kg body weight. Mortalities, clinical findings, autopsy and body weight changes were monitored daily for the 14 days following the administration according to the Regulation of Korean Food and Drug Administration. Results : We observed survival rates, general toxicity, change of body weight, and autopsy. Single oral administration of YJT with different dosages, no animals died of the test drug. Autopsy of animal revealed no abnormal gross finding. Therefore, $LD_{50}$ value of YJT for ICR mice was more than 5000 mg/kg on oral route. Conclusions : These results suggest that no toxic dose level of YJT in mice is considered to be more than 5000 mg/kg. Consequently, it was concluded that YJT have no effect on acute toxicity and side effect in ICR mice.

• The Korean Journal of Applied Statistics
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• v.30 no.5
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• pp.633-645
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• 2017

This study proposes a statistical procedure for analyzing container ship operation data that can help determine fuel consumption patterns. We first investigate the features that affect fuel consumption and develop the prediction model to find current fuel consumption. The ship data can be divided into two-type data. One set of operation data includes sea route, voyage information, longitudinal water speed, longitudinal ground speed, and wind, the other includes machinery data such as engine power, rpm, fuel consumption, temperature, and pressure. In this study, we separate the effects of external force on ships according to Beaufort Scale and apply a partial least squares regression to develop a prediction model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.582-585
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• 2018

As traffic volume increases and road networks become more complicated, identifying for accurate traffic flow and driving smooth traffic flow are a concern of many countries. There are various analytical techniques and studies which desire to study about effective traffic flow. However, the necessary activity is finding the traffic flow pattern through data visualization including location information. In this paper aim to study a real-world urban traffic trajectory and visualize a pattern of traffic flow with a simulation tool. Our experiment is installing the sensor module in 40 taxis and our dataset is generated along 24 hours and unscheduled routes. After pre-processing data, we improved an open source traffic visualize tools to suitable for our experiment. Then we simulate our vehicle trajectory data with a dots animation over a period of time, which allows clearly view a traffic flow simulation and a understand the direction of movement of the vehicle or route pattern. In addition we further propose some novel timelines to show spatial-temporal features to improve an urban environment due to the traffic flow.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.61-74
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• 2013

In digital age export expansion is the key fact of promoting Korea's economic growth. The policy that encourages exportation is being more emphasized to develop of the nation's economy. From the 90's, regionalism has been widespread throughout the world with globalization and internationalization led by WTO and FTA. The world is now becoming one economic bloc. It is necessary to understand how enterprises contribute to the exportation to establish and manage the policy that encourage and support the exportation. This study estimates SME's level of contribution on gross exports and understands the problem, while looking for better statistical alternatives and finding SME's export energizing policies. It is estimated that domestic SMEs contribute about 40-50% of gross exports. SME bureau and national statistical office should select optimal size of population of each industry, design and extract sample to conduct the export related survey extensively. SMEs should analyze the product and skills of the industry that is dominated by major companies to contribute to the exportation more efficiently. This effort will increase the level of contribution to gross exports in general.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3B
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• pp.224-236
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• 2003

MANET(Mobile Ad hoc networks) is a mobile, multi-hop, and wireless network which is bandwidth constrained, energy constrained, resource constrained, autonomous, and self operating systems with dynamic topology. These constraints make the routing between communicating nodes in ad hoc networks difficult. In this paper we survey several routing protocol for mobile ad hoc networks. Especially, we focus on Zone Routing Protocol, hybrid routing framework suitable for a wide of mobile ad hoc networks and analyze performance of ZRP. In the case of ZRP protocol, it is essential that the use of optimal zone radius for efficient use. Otherwise it was proved through an simulation that performance of whole network is rapidly decrease with greatly increasing overhead of ZRP traffic that need for transmission of packet by IARP or IERP traffic. Also we suggest the process of finding QoS path that use in-band signal for QoS routing in ad hoc network. This method guarantees route that make real time multimedia service for QoS enabled path.

• Korean Medical Education Review
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• v.18 no.2
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• pp.99-105
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• 2016

The purpose of this study was to inquire into the knowledge of medical students on the Middle East respiratory syndrome (MERS) and evaluate whether infection prevention education impacts students' level of knowledge and individual hygiene practices. This study also investigated the route by which medical students obtain disease-related information. The study involved a survey conducted in August of 2015 at two medical schools in Busan. In the first year to fourth year, a total of 345 students are enrolled (111 students in A school and 234 students in B school). Before the study was carried out, university A performed infection prevention education related to MERS, but B did not. We used self-developed questionnaires to survey the demographic characteristics, routes of acquisition of MERS information, degree of knowledge of MERS, educational satisfaction, and personal hygiene practices before and after education. Knowledge level differences according to gender and year in school were not statistically significant. Students obtained their information about MERS from various news media sources and the Internet, and through social network sites. Students practiced sanitary control behaviors in an average of 2.2 manners (standard deviation=0.95). The level of knowledge of MERS revealed a positive correlation with the frequency and total numbers of personal hygiene practices. This finding suggests that the infection prevention education program played a role in knowledge acquisition and personal hygiene practices for the medical students. In order to provide accurate and reliable knowledge of disease and preventive health behavior to medical students, continuous and well-planned education programs are necessary.

• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.22-30
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• 2022

The reinforcement learning algorithm has proven its potential in solving sequential decision-making problems under uncertainties, such as finding paths to route data packets in wireless sensor networks. With reinforcement learning, the computation of the optimum path requires careful definition of the so-called reward function, which is defined as a linear function that aggregates multiple objective functions into a single objective to compute a numerical value (reward) to be maximized. In a typical defined linear reward function, the multiple objectives to be optimized are integrated in the form of a weighted sum with fixed weighting factors for all learning agents. This study proposes a reinforcement learning -based routing protocol for wireless sensor network, where different learning agents prioritize different objective goals by assigning weighting factors to the aggregated objectives of the reward function. We assign appropriate weighting factors to the objectives in the reward function of a sensor node according to its hop-count distance to the sink node. We expect this approach to enhance the effectiveness of multi-objective reinforcement learning for wireless sensor networks with a balanced trade-off among competing parameters. Furthermore, we propose SDN (Software Defined Networks) architecture with multiple controllers for constant network monitoring to allow learning agents to adapt according to the dynamics of the network conditions. Simulation results show that our proposed scheme enhances the performance of wireless sensor network under varied conditions, such as the node density and traffic intensity, with a good trade-off among competing performance metrics.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.103-117
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• 2009

In MANET(Mobile Ad-Hoc Network), providing security to routing has been a significant issue recently. Existing studies, however, focused on either of secure routing or packet itself where malicious operations occur. In this paper, we propose SRPPnT(A Secure Routing Protocol in MANET based on Malicious Pattern of Node and Trust Level) that consider both malicious behavior on packet and secure routing. SRPPnT is identify the node where malicious activities occur for a specific time to compose trust levels for each node, and then to set up a routing path according to the trust level obtained. Therefore, SRPPnT is able to make efficient countermeasures against malicious operations. SRPPnT is based on AODV(Ad-Hoc On-Demand Distance Vector Routing). The proposed SRPPnT, from results of the NS-2 network simulation. shows a more prompt and accurate finding of malicious nodes than previous protocols did, under the condition of decreased load of networks and route more securely.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.132-133
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• 2023

The safe evacuation of people during disasters is of utmost importance. Various life safety evacuation simulation tools have been developed and implemented, with most relying on algorithms that analyze maps to extract the shortest path and guide agents along predetermined routes. While effective in predicting evacuation routes in stable disaster conditions and short timeframes, this approach falls short in dynamic situations where disaster scenarios constantly change. Existing algorithms struggle to respond to such scenarios, prompting the need for a more adaptive evacuation route algorithm that can respond to changing disasters. Artificial intelligence technology based on reinforcement learning holds the potential to develop such an algorithm. As a fundamental step in algorithm development, this study aims to evaluate whether an evacuation algorithm developed by reinforcement learning satisfies the performance conditions of the evacuation simulation tool required by IMO MSC.1/Circ1533.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.343-353
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• 2006

Giardia intestinalis infections arise primarily from contaminated food or water Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes more specifically than the known 2 genotypes recovered from humans have been developed using the intergenic spacer (IGS) region of rDNA. The IGS region contains varying sequences and is thus suitable for comparing isolates once they are classified as the same strain. Genomic DNA was extracted from cysts isolated from the feces of 5 Chinese, 2 Laotians and 2 Koreans infected with G. intestinalis and the trophozoites of WB, K1, and GS strains cultured in the laboratory, respectively. The rDNA containing the IGS region was amplified by PCR and cloned. The nucleotide sequence of the 3' end of IGS region was determined and examined by multiple alignment and phylogenetic analysis. Based on the nucleotide sequence of the IGS region, 13 G. intestinalis isolates were classified to assemblages A and B, and assemblage A was subdivided into A1 and A2. Then, the primers specific to each assemblage were designed, and PCR was peformed using those primers. It detected as little as 10 pg of DNA, and the PCR amplified products with the specific length to each assemblage (A1, 176bp; A2, 261 bp; B, 319 bp) were found. The PCR specific to 3 assemblages of G. intestinalis did not react with other bacteria or protozoans, and it did not react with G. intestinalis isolates obtained from dogs and rats. It was thus confirmed that by applying this PCR method amplifying the IGS region, the detection of G. intestinalis and its genotyping can be determined simultaneously.