• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.137-142
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• 2016

A two-step open system(TOS) was proposed to relay between a healing platform and a repository of personal health documents. TOS was designed by taking into consideration the pubsub service based on large scale connections to monitor a provider's access/request process for health documents in real time. TOS, however, uses WebSocket as a communication protocol in case of pubsub. Given the operational environment of low quality wireless networks for mobile devices that are user terminals in a healing platform, there is a need to add a messaging protocol to support QoS as well as a transmission protocol. As a light messaging protocol optimized for mobile devices, MQTT defines reliable messaging QoS to consider a wireless network situation of low speed/low quality. This study designed an MQTT protocol-based message broker to support QoS in case of large scale connections and pubsub by taking into consideration mobile devices that are user terminals in a healing platform. After designing a model between TOS and MQTT message broker, the study implemented a prototype based on the proposed design and compared it with its counterparts from previous studies based on the performance indicators in a load-test with the MQTT client tool.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.10 no.16
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• pp.101-106
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• 1987

Statistical control charts are useful tools to monitor and control the manufacturing processes and are widely used in most Korean industries. Many Korean companies, however, do not always obtain desired results from the traditional control charts by Shewhart such as the $\bar{X}$-chart, $\bar{X}$-chart, $\bar{X}$-chart, etc. This is partly because the quality charterstics of the process are not distributed normally but are skewed due to the intermittent production, small lot size, etc. In Shewhart $\bar{X}$-chart. which is the most widely used one in Kora, such skewed distributions make the plots to be inclined below or above the central line or outside the control limits although no assignable causes can be found. To overcome such shortcomings in nonnormally distributed processes, a distribution-free type of confidence interval can be used, which should be based on order statistics. This thesis is concerned with the design of control chart based on a sample median which is easy to use in practical situation and therefore properties for nonnormal distributions may be easily analyzed. Control limits and central lines are given for the more famous nonnormal distributions, such as Gamma, Beta, Lognormal, Weibull, Pareto, Truncated-normal distributions. Robustness of the proposed median control chart is compared with that of the $\bar{X}$-chart; the former tends to be superior to the latter as the probability distribution of the process becomes more skewed. The average run length to detect the assignable cause is also compared when the process has a Normal or a Gamma distribution for which the properties of X are easy to verify, the proposed chart is slightly worse than the $\bar{X}$-chart for the normally distributed product but much better for Gamma-distributed products. Average Run Lengths of the other distributions are also computed. To use the proposed control chart, the probability distribution of the process should be known or estimated. If it is not possible, the results of comparison of the robustness force us to use the proposed median control chart based oh a normal distribution. To estimate the distribution of the process, Sturge's formula is used to graph the histogram and the method of probability plotting, $\chi$$^2$-goodness of fit test and Kolmogorov-Smirnov test, are discussed with real case examples. A comparison of the proposed median chart and the $\bar{X}$ chart was also performed with these examples and the median chart turned out to be superior to the $\bar{X}$-chart.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.50-60
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• 1987

Sensitivity, expressed in the $96h-LC_{50}$ determined with continuous flow system, was compared for eight developmental stages of Oryzias latipes with butachlor, diazinon and fenitrothion. Significance of the laboratory determined $96h-LC_{50}$ in real field situation was evaluated for butachlor using outdoor model agrosystem. In the laboratory tests, the most sensitive stage was post-larva stage IV(7 days after hatching) with $96h-LC_{50}$ of 0.14, 1.4, and 1.6ppm for butachlor, diazinon and fenitrothion, respectively, whereas the least sensitive stage was early embryo stage(1 day after fertilization), and then the susceptibility was somewhat stable after 21days after hatching. In the model agrosystem test, the highest concentration of 0.53ppm of butachlor in water was obtained at the 2nd day after application. The stages IV and VIII showed mortality of over 50% at 96 hours after application. It is concluded that the conventional use of butachlor in the field would cause significant adverse effect on O. latipes. It is suggested that sensitivity test at the early life stages with fish is an important part of the ecotoxicological assessment of chemicals.

• Journal of Korea Port Economic Association
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• v.35 no.2
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• pp.61-76
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• 2019

The purpose of this study is to use the EGARCH model and Granger causality test to analyze how the change in the BDI affects the Korean stock price volatility. The main analysis results are summarized as follows. First, according to the results of the mean equation, the change in the BDI is significant in large-cap stocks, as well as in the manufacturing, service, and chemistry indexes, but not in others. This implies that the Korean stock market does not respond appropriately to the maritime market situation; further, the increase in demand for raw materials has not led to a real economic recovery. Second, in the result of the variance equation, the coefficient on the change in the BDI is negative(-), and the change in the BDI is significant for all size indexes. Particularly, the change in the BDI has a greater impact on the volatility of small-cap stocks than that of large-cap stocks. The results of the analysis of the sector indexes were statistically significant for the service, financial, construction, and electric and electronics industries, but not for the manufacturing and chemical industries. In particular, the changes in the BDI have the greatest impact on the construction industry. Third, according to the Granger causality test results, the change in the BDI leads the financial industry and construction industry. There is, however, no relationship between the BDI and the other indexes. This shows that change in the shipping freight index can be used to predict the volatility in the Korean stock market. This can help investors and policymakers make better decisions.

• Journal of Distribution Science
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• v.11 no.8
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• pp.25-30
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• 2013

Purpose - Foodservices have grown to over 60% of the franchise industry. However, despite reaching this high level, the foodservice franchise industry is experiencing severe ups and downs. While factors such as expansion by franchises and the entry of large multinational firms are causing this imbalance, the more serious problem faced by franchisees is the lack of know-how and correct operating procedures. Franchise headquarters should advise franchisees on important matters such as food ingredients, interior design, tableware, and fixtures. However, even though franchise headquarters have the ability to impart such management know-how, this is often a neglected area. Research design, data and methodology - This study was conducted in an industrial environment to present suitable competitive alternatives for foodservice franchises. Empirical analysis was conducted using a sample of 232 people with experience in targeting customers. The main purpose of this study is not to identify and analyze the factors affecting customer satisfaction. Customers of the Food Service Industry to invite contacts until departure for the service flow by identifying the expectations and allow this area by analyzing the resulting measures to enhance the competitiveness has presented. Results - Actual results contact factors affecting the quality of service on customer satisfaction was a significant influence. However, the end of this analysis, the actual customer satisfaction directly affects the quality of service that is only important factor can commit mistakes. Relatively large impact on customer satisfaction, which is relatively independent of the quality factor should be a review of zone of tolerance. In this study, eating phase relative to contact the service customer satisfaction was the most influential. The results, however, zone of tolerance for an area in the waiting and ordering dissatisfaction factors are appearing. And in the course of these services outside the zone of tolerance area is unsatisfactory evaluation is being done. Conclusions - After all, Foodservice, the contact service management for zone of tolerance the top priority should be can be seen. Foodservice contact first in the case of service quality factors caused by the continuous flow of services, so this step-by-step identification needs to be clearer. This, of course, to distinguish between the actual per unit of activity appears to be more difficult to follow, for it seems to need a lot of future complementary. Next is the assessment of customer service quality. Customers remember the experience for the services of a real contact through the assessment and service evaluation clearly emerge as the expected level can be difficult. However, this situation is controlled by the test method cannot be avoided unless there is no limit to the number of leave. Despite these limitations, the next step to contact a service evaluation and analysis have to continue to refine and thereby franchisees for the operation of the store in terms of practical know-how required to provide to the office believe.

• Spatial Information Research
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• v.23 no.1
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• pp.59-68
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• 2015

As part of an effort to leap smart cadastre system by doing rearrangement of various mismatches in the land register, the cadastre renovation project is being recently conducted. In response to this demand, this paper proposes an image-based rapid parcel boundary demarcation plan using the high resolution aerial image with a GSD (Ground Sample Distance) of 5cm that matches to real ground boundary situation in residential area. To review the feasibility and accuracy of this proposed methodology, we compared the accuracy of parcel boundary point and parcel area extracted from the digital stereo plotting on the basis of results of cadastral boundary surveying and land register over the selected two test areas. The comparative accuracy result of all boundary points by digital stereo plotting is satisfied with accuracy requirement according to the criteria of the enforcement regulation of cadastral surveying, whereas it exceeded allowable error of ${\pm}0.07m$, more strictly specified in the Special Act on Cadastral Renovation. And about 20% of the total 70 parcels extracted by digital plotting are out of area tolerance in Jecheon study area, and 10% of the total 19 parcels in Suwon study area. The parcels exceeding accuracy limit are mostly due to the occlusion caused by building roof or eaves, and the obstacles such as trees existing on the boundary. Furthermore, an object identification is impossible in image because of vague boundary reference in case of nonexistence of man-made structures or natural features. Therefore, the utilization of boundary identification stickers is recommended as a solution for these types of land parcel.

• Journal of Science Education
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• v.33 no.2
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• pp.353-364
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• 2009

The purpose of this study was to develop 'the problem situations' for the Problem Based Learning(PBL) and to examine it's effects on the science achievement and the attitude towards science learning. Also the students' perception on the PBL model was examined. The topics of the problem situations developed were 'the future energy for reducing the green house effect' and 'the Indonesian forest fire and the El Nino'. The coaching strategies for the PBL were designed and implemented to 10th grade high school students in the science classes, the results are follows; First, the science achievement of the group of PBL is significantly higher than those of group of traditional teaching. Second, the scores of the test of attitude toward science learning of the group of PBL is significantly higher than those of group of traditional teaching. Third, the students' perception of the PBL was positive. Many students have interests and motivations in PBL, some students have difficulties in learning on the PBL. In the students' personal reflection notes the step of a problem statement is the hardest one of the PBL model. Therefore, this study suggests that developing the problem situations based on real context is of great importance for implementing a problem based learning model continuously.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.402-410
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• 2020

Purpose: The purpose of this research is to eliminate communication shadowing loss of the 'smart safety management system'. The 'smart safety management system' can monitor and relay real time data of workers working in high risk workplace (i.e: industrial scene, disaster scene). The data will provide the rescue team the 'golden hour' in their rescue operations. Method: In this research, safety tag was designed and implemented so that it acts as a repeater for the user. Result: In other words, when communication in-between the safety tag and headquarters' communication terminal is jeopardized, the safety tag will act as a repeater-terminal for other safety tags in the area. Conclusion: The research tested if a specific building with communication shadowing loss problem was resolved when safety tags were implemented. Communication shadowing was first identified in-between the safety tag and headquarters' communication terminal. When extra safety tags were deployed in the same situation, the results showed that the communication shadowing loss was resolved. The repeater safety tags could resolve communication shadowing loss of up to three basement levels in this test building.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.436-445
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• 2019

This study quantitatively evaluates the economic value of an intelligent crime-zero testbed by using the contingent valuation method (CVM), which is the most effective for non-market valuations in fields like crime prevention. To minimize hypothetical convenience and increase respondents' awareness regarding the actual situation, an analysis was conducted for Indukwon District, Anyang City, Gyeonggi-do, by using the intelligent crime prevention technologies and solutions being developed by the KICT Research Center. This analysis was aimed at providing a systematic basis for determining the feasibility of crime prevention-related public projects. As a result, the WTP of Anyang citizens in the intelligent crime prevention demonstration district was estimated to be 7,160 won. The analysis shows that the area of Gwanyang 2, where the test bed belongs, has a high economic value of KRW 660 million per year, and KRW 51.4 billion per year when expanded to Anyang City. This study is significant in that it provides the first domestic evaluation of the crime-zero testbed. In addition, it has academic and practical value for a future-oriented service model by using intelligent crime prevention technologies and solutions that can be applied in real life and to the crime-zero testbed.

• Tunnel and Underground Space
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• v.11 no.4
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• pp.319-327
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• 2001

Introduction of new design tools has been required to optimally design and operate the ventilation system of long vehicle tunnels.. The demand has led to wide spread use of the simulation technique throughout the would to analysis the dynamic relationship among the variables associated with vehicle tunnel ventilation. This paper aims at performing on-site study at local tunnels to test the applicability of NETVEN, a simulation model vehicle tunnel ventilation. The study was carried out at four urban as well as highway tunnels model of vehicle tunnel ventilation. The study was carried out at four urban as well as highway tunnels employing different ventilation systems as well as traffic methods. There were some discrepancies sound between the simulation output and measurements and the following four factors are considered to mainly cause those disagreement. (1) The real situation shows distinctive transient and retarding characteristics with respect to air flow and contaminant dispersion, while ventilation forces are not steady-state and in particular those traffic and climatic variables show significant instantaneous variation. (3) Near the exit portal, the CO levels show bigger differences. The general trend is that data with higher CO concentrations carry bigger discrepancies. Turbulent diffusion is though to be the main reason for it and also contribute to the fact hat the highest CO concentrations are found at the locations somewhat inward, not at the exit portals. (4) Higher traffic rate results in higher discrepancies of ventilation velocity. Along with the exhaust characteristics, the vehicle aerodynamic characteristics need to be studied continuously in order to reduce the velocity disagreement.