• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.392-401
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• 2020

Purpose: This study analyzes the operating characteristics of a lithium ion capacitor that can be used as a standby power supply in an emergency, and determines whether the standby power supply is abnormal even by measuring the voltage using a linear proportionality characteristic during charging and discharging. The aim is to provide an experimental basis that can be done. Method: As a method for this study, first, analyze the operation principle and characteristics of the existing backup power supply and lithium ion capacitor, and then measure the voltage of the lithium ion capacitor according to the configuration and system block diagram of the induction lamp used in the experiment. We proceed with the test of the measured value of discharge power for each voltage band to check the amount of power held by the battery and the operation test experiment using induction lamps. Results: Just by checking the charging voltage using the linear proportional characteristics of lithium ion capacitors, it provides a basis for accurately inferring the effective operating time of induction lamp lamps. Conclusion: In the event of a disaster, the lithium ion capacitor is used as a spare power supply for emergency induction lamps to prevent complete discharge of emergency induction lamps, to prevent the problem of performing normal operation of the standby power supply, and to use only a simple voltage measurement to reserve power. It was intended to suggest many uses for evacuation equipment application in the future by making it possible to check whether the device is abnormal.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.461-468
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• 2001

The effectiveness and safety of Enzyme Food, a group of dietary supplements designated by Korean Food Law, were evaluated and the possibility of HACCP (Hazard Analysis Critical Control Point) application was investigated. Chemical composition, enzyme activities and the degree of bacterial contamination in 12 samples of different brands sold in Korean market were measured. The chemical composition of the selected products varied and inconsistent to those claimed in the label description. It is known that effectiveness of Enzyme Food depends on enzyme activity, but enzyme activities of ${\alpha}-amylase$ varied from $1,793\;{\mu}g/min$ g to $159\;{\mu}g/min$ g and those of ${\beta}-amylase$ ranged from $171\;{\mu}g/min$ g to $11\;{\mu}g/min$ g. The protease activities varied from $27.57\;{\mu}g/min$ g to $0.18\;{\mu}g/min$ g. In coli-form bacterial test, positive reactions were appeared in the 50 % of the samples. Numbers of bacteria ranged from $1.3\;{\times}\;10^5\;to\;1.2\;{\times}\;10^9$. Five CCPs were identified; heating, inoculation, cultivation, drying and granulation. Consideration of HACCP system indicated that the pretreatment of raw material, checking of bacterial contamination and stability of enzyme activity during fermentation process were important factors for the quality of Enzyme Foods.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.182-191
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• 2015

The Korean government introduced an automated speed enforcement system (ASES), which uses traffic enforcement cameras, to counteract safety issues that are caused by speeding. As the information of the traffic enforcement camera locations is provided to the drivers via navigation systems and mobile applications in a timely manner, drivers can avoid enforcement by momentarily diminishing their speeds only near the camera locations. To prevent drivers' evasional behavior and improve the effectiveness of ASES, section control, which enforces speeding vehicles by measuring their average travel speeds over a stretch of road and checking against the speed limit, has been recently implemented. In this study, Section Speed Enforcement Zone and Comparison Zone are compared in terms of traffic stream characteristics under free flow conditions. To this end, loop detector data were obtained from the three study sites and analyzed. The study results demonstrated that drivers maintain their speeds below the speed limit over the enforcement section with a lower variance of speeds.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.254-262
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• 2018

It was intended to check a possibility of activity of Psidium guajava leaf extract as anti-oxidant and anti-inflammatory material. Total polyphenol and total flavonoid content of Psidium guajava leaf extract was checked. Cream having inhibitory effect on inflammation through toxicity and NO production inhibition in RAW 264.7 cell was manufactured, and skin safety was evaluated. It was confirmen that total polyphenol and flavonoid content of Psidium guajava leaf extract was 126.4 mg/g and 223.17 mg/g respectively, which was high content. According to the results of checking toxicity through cell viability in RAW 264.7 cell, cytotoxicity was not shown. And NO production indicating inflammatory disease was inhibited concentration-dependently. According to the results of carrying out single patch test after manufacturing the cream containing the Psidium guajava leaf extract, skin irritation did not occur for 24 h to put patch on skin or for 24 h after removing the patch. Putting these results together, it was verified that there was possibility of application as raw materials for cosmetics, which would have anti-oxidant activity owing to the high polyphenol and flavonoid content of Psidium guajava leaf extract and anti-inflammatory material through NO production inhibition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.681-688
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• 2018

As environmental regulations have been strengthened and high fuel efficiency has been in demand in recent years, the number of ships using natural gas as a fuel is increasing. The demand for ships using LPG or methanol, which are emerging as eco-friendly vessel fuels, is also increasing. In this perspective, ME-LGI engines using LPG or methanol as a fuel have attracted considerable attention. Ships equipped with an ME-LGI engine are required to check the reliability of the fuel injection valve during shipping. This means that the development of a fuel injection valve tester is essential for the commercialization of ME-LGI engine. This study conducted the conceptual design of a fuel injection valve tester for ME-LGI engines using a system engineering process in the order of requirements analysis, functional analysis, and design synthesis. In the requirement analysis stage, the operating process of fuel injection valve was analyzed, and the necessity of checking the sealing oil leakage was then derived. In the functional analysis stage, the functions and flow of them were defined at each functional level. In the design synthesis stage, the equipment for each function was set and the process block diagram based on it was derived. In addition, preliminary risk analysis was performed as a part of system analysis and control, and safety measures were added to the conceptual design. This study is expected to be a good reference material for the concept design of other systems in the future because it shows the application process of a system engineering process to the conceptual design in detail.

• Journal of the Korean Society for information Management
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• v.26 no.2
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• pp.149-172
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• 2009

The purpose of this study was to examine the demand of parents and teachers for a children's library and analyze the need in consideration of their age and children's library-using frequency. The subjects in this study were 1,500 parents and teachers in the region of Gwangju, on whom a survey was implemented to find out the necessity of a children's library, what should be considered in terms of design and program development and what forms of materials should be provided. As a result of checking their needs for the functions of a library, the parents and teachers investigated attached importance to culture, welfare and hands-on culture/art programs as what a library should focus on. Second, as for design, they gave top priority to comfortableness(sanitary facilities, ventilation, humidity and temperature) and safety(sofas, cushions and carpets for children). Third, as to program preference, both of the parents and teachers considered activity, performance and educational programs necessary among multiple kinds of ongoing programs. Specifically, performance programs ranked first among the parents and third among the teachers. Activity programs ranked first among the teachers and third among the parents. Fourth, concerning the importance of materials possessed by a library, they placed the most emphasis on the kind of materials that could foster creativity and instill the right personality.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.212-218
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• 2003

State invariant is a property that holds in every reachable state. It can be used not only in understanding and analyzing complex software systems, but it can also be used for system verifications such as checking safety, liveness, and consistency. For these reasons, there are many vital researches for deriving state invariant from finite state machine models. In previous works every reachable state is to be considered to generate state invariant. Thus it is likely to be too complex for the user to understand. This paper seeks to answer the question `how to simplify state invariant\ulcorner`. Since the complexity of state invariant is strongly dependent upon the size of states to be considered, so the smaller the set of states to be considered is, the shorter the length of state invariant is. For doing so, we let the user focus on some interested scopes rather than a whole state space in a model. Computation Tree Logic(CTL) is used to specify scopes in which he/she is interested. Given a scope in CTL, mixed reachability analysis is used to find out a set of states inside it. Obviously, a set of states calculated in this way is a subset of every reachable state. Therefore, we give a weaker, but comprehensible, state invariant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.694-702
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• 2017

In the case of an elevated railway station, structure borne noise and vibration due to structural limitations allow the load and vibration from railway vehicles to be directly transmitted to the station structure, resulting in an increase in the number of civil complaints from customers and staff of the station. The floating slab track system, which is well known as one of the solutions for reducing the noise and vibration from elevated railway stations, usually contains rubber mounts or rubber pads under the railway slab which act as a damper. These types of device have the disadvantage that is difficult to predetermine the exact stiffness and damping ratio under the nonlinear loads resulting from train services. In this study, an isolator with a friction type of wedge is introduced, which can be applied to floating slab track systems and to be designed with precisely the required stiffness. Furthermore, a comparative analysis of the stiffness between the designed and experimental values is carried out, while the damping ratio, which is closely related to the friction wedge blocks, is deduced according to the train load condition. The performance tests of the isolator were conducted in accordance with the DIN 45673-7 standard which includes both static and dynamic load tests. The load conditions for the performance tests are designed to conform to the DIN standard related to the weight of the train and rail track, in order to perform vertical and horizontal load tests, so as to ensure the secure structural safety of the railway. Also, by checking the change aspect of the friction coefficients of the friction elements according to the loading rate, the vibration reduction performance of the friction type isolator with variable loading rate conditions is examined.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.221-227
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• 2013

RFID is an automatic identification technology that can control a range of information via IC chips and radio communication. Also known as electronic tags, smart tags or electronic labels, RFID technology enables embedding the overall process from production to sales in an ultra-small IC chip and tracking down such information using radio frequencies. Currently, RFID-based application and development is in progress in such fields as health care, national defense, logistics and security. RFID structure consists of a reader that reads tag information, a tag that provides information and the database that manages data. Yet, the wireless section between the reader and the tag is vulnerable to security issues. To sort out the vulnerability, studies on security protocols have been conducted actively. However, due to difficulties in implementation, most suggestions are concerned with theorem proving, which is prone to vulnerability found by other investigators later on, ending up in many troubles with applicability in practice. To experimentally test the security of the protocol proposed here, the formal verification tool, CasperFDR was used. To sum up, the proposed protocol was found to be secure against diverse attacks. That is, the proposed protocol meets the safety standard against new types of attacks and ensures security when applied to real tags in the future.

• Research in Community and Public Health Nursing
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• v.4 no.1
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• pp.14-24
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• 1993

The Purpose of this study was to explore the condition of periodic medical examination and the health care services of industries in order to offer some basic data on developing industrial nursing care. To achieve this goal a self - administered questionnaire (developed by the academic affairs of community health nursing) was provieded to the nurses in 56 industries from Dec. 10, 1992 to Jan. 20, 1993. The statistical computer package, SPSS, was used to manipulate the data along with T-test and ANOVA. The results were as follows : 1. General characteristics: The greater part of the industries were manufacturing company, and below 300 employees of industry were 55.4%. The shift system was mostly one shift(66.1%) and three shift(23.2%), and 50.0% them organized the Industrial Safety and Health Commitee. Average a number of employees was 631 person. 2. Periodic Medical Examination: Most of the workers were receiving periodic medical examination from the designated hospital (95.71%). From the about 12.89% were gone through a colse medical examination. In colse medical examination 58.41% were decided 'C' and 36.73% were decided 'D'. About 6.23% off those who had any clinical findings were work-time shortening(7.84%), work-transition(8.12%), recoverating at home. The majority of the workers receive the result of the periodic medical examination individually (78.5%). 3. Special medical examination: The rate of those who are receiving special medical examination were 76.82% and about 8.24% were decided 'C' and 1.23% were decided 'D' Those who had any health problems were receiving follow-up checking (9.10%) and medical treatment while working (15.04%). The health managers in the company can consult (85.7%) those who had any suspicious sign and symptoms of occupational disease. 4. Health care services: The average score of health care services were 17.57 point out of 28 point, and the score was lower in health assessment and environmental hygiene than medical diagnosis and health education. There were significant differences in environmental hygine (F=3.72, P=0.017), health care services(F=3.94, P=0.013) according to the size of the size of the industries The other's significancy is not shown by any type of industrial nurse. The level of health care services were higher in the wokers who had better health and showed no singificant differences(T=-0.73, P=0.470).