• Journal of Ocean Engineering and Technology
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• v.21 no.5
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• pp.33-38
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• 2007

The welding methods have been applied in the most structural products from multi-field of automobile, ship construction and construction, and so on. The structure steel must have enough strength of structure. In this study, SS400 steel and STS304 steel were used to estimate the corrosion characteristics of the weld thermal cycle simulated HAZ. To evaluate the corrosion characteristics, also, the materials with two conditions were used in 3.5% NaCl. The one is to the drawing with diameter of ${\Phi}10$ and the other is to the residual stress removal treatment. The electrochemical polarization test and immersion test were carried out. From test results, corrosion potential, corrosion current density, weight loss ratio and corrosion rate were measured. In the kinds of SS400 steels, corrosion potential of weld thermal cycle simulated specimens after the heat treatment showed somewhat the direction of noble potential. And in the base metal to be drawing weight loss ratio and corrosion rate occurred higher than the other kinds. In the kinds of STS304 steels, the result of base metal to be drawing was similar to results of SS400 steels, too. Two kinds of $750^{\circ}C$ and $1300^{\circ}C$ of weld thermal cycle simulation after the heat treatment were rather higher than the other kinds in weight loss ratio and corrosion rate.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.103-110
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• 2020

The fire incident of KT's Ahyun branch occurred last year indicates that hyper-connected society led by 5G technology would be a dystopia instead of a utopia unless seamless connection of 5G service is well secured. Looking backward on 1999, we could peacefully and happily greet the new millennium by making a great effort to prevent the millennium bugs(Y2K) from causing the catastrophe such as a shut-down of banking system. Likewise, we should make a great effort to keep 5G networks and 5G service continuously working without the disruption of even just a second, which would enable us to avoid facing any catastrophes caused by the disruption of 5G service. As a way to do so, it can be considered that 5G service is designated as universal service because it has the key features of public goods like telephone and high-speed internet services.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.79-84
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• 1998

The study result on the domestic waste occurrence and admistration condition of Iksan City as follows ; 1. The year of 1995 has observed a radically decreasing ratio of per capita waste generation compared to the previous year by 26.2%, owing to the publication of the new amendment of volume based charge as well as to the rural population included through the merger of Iksan City and Iksan Country ; the daily quantity of domestic waste for Iksan residents in 1997 was calculated to be $0.66kg/capita{\cdot}day$. 2. Waste generation in nonresidential areas were $8.04kg/capita{\cdot}day$ in average ; the quantity per capita in market places was observed to generate the largest, $36.76kg/capita{\cdot}day$, while that of services was the smallest $0.25kg/capita{\cdot}day$. 3. The average generation per capita of household waste was $0.23kg/capita{\cdot}day$ in the area which has no volume based charge system. This area showed no difference from those of other areas ; the apparent density of the waste recorded the lowest $0.llkg/{\ell}$ for District Offices, while the highest among the classified fields was $0.40kg/{\ell}$ of the Fire Station. 4. Iksan City showed great contribution by decreasing the absolute quantity of waste for landfill by waste classfication, according to the days of the week and reutilizing recyclable waste since August, 1997. 5. Location of a landfill site for disposal of nonrecyclable waste will cause a serious problem to the community and it will be highly recommendable to have governmental support and professtional consultation as well as open discussions, such as hearings, for the settlement of the problem.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.43-54
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• 2007

The effective power consumption is the primary issue in a sensor network which consists of the sensor nodes with limited battery power. So, most of the MAC protocols in sensor networks have been designed with the consideration of energy efficiency. Generally, these protocols make use of the listen and sleep mode periodically. However, this approach inevitably causes a long transmission delay on the data forwarding path, which is mainly resulted from the sleep time of the receiver node. This paper deals with a design of DT-MAC(Data Transmission centric MAC) protocol, with minimizes the data transmission delay while it forces each node to consume its energy efficiently. Thus, a node received a packet converts its remained sleep time to the pseudo_listen time, in which the node is able to transmit a packet. With benefit of the pseudo_listen period, the data transmission delay along with the data forwarding path will be shortened as much as it possible. Therefore, DT-MAC protocol is very suitable to the various applications which require a real time sensing data such as disaster and fire alarm.

• Journal of Communications and Networks
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• v.10 no.4
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• pp.455-464
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• 2008

To provide network services consistently under various network failures, enterprise networks increasingly utilize path diversity through multi-homing. As a result, multi-homed non-transit autonomous systems become to surpass single-homed networks in number. In this paper, we address an inevitable problem that occurs when networks with multiple entry points deploy firewalls in their borders. The majority of today's firewalls use stateful inspection that exploits connection state for fine-grained control. However, stateful inspection has a topological restriction such that outgoing and incoming traffic of a connection should pass through a single firewall to execute desired packet filtering operation. Multi-homed networking environments suffer from this restriction and BGP policies provide only coarse control over communication paths. Due to these features and the characteristics of datagram routing, there exists a real possibility of asymmetric routing. This mismatch between the exit and entry firewalls for a connection causes connection establishment failures. In this paper, we formulate this phenomenon into a state-sharing problem among multiple fire walls under asymmetric routing condition. To solve this problem, we propose a stateful inspection protocol that requires very low processing and messaging overhead. Our protocol consists of the following two phases: 1) Generation of a TCP SYN cookie marked with the firewall identification number upon a SYN packet arrival, and 2) state sharing triggered by a SYN/ACK packet arrival in the absence of the trail of its initial SYN packet. We demonstrate that our protocol is scalable, robust, and simple enough to be deployed for high speed networks. It also transparently works under any client-server configurations. Last but not least, we present experimental results through a prototype implementation.

• Journal of The Korea Institute of Healthcare Architecture
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• v.26 no.1
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• pp.73-84
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• 2020

Purpose: Though Korean healthcare services have been upgraded, infection and fire had been broken out in general hospitals. And higher concerns about quality assessment made it to clinical laboratory design guideline studies. So, this study investigates the facilities, equipment and personnel of laboratory medicine focusing on more than five hundred fifty bed hospital, and contributes to make guidelines for safety and efficiency in lab. Methods: Questionnaires to supervisor technologist and field surveys to medical laboratories in korean hospitals have been conducted for the data collection. 16 answers have been analysed statistically by MS Excel program. Results: Most of the sample tests such as hematology, clinical chemistry, immunology, transfusion, urinalysis, microbiology and molecular diagnosis are performed by more than 80% in large sized general hospital laboratory. In the test methods, automatic analyzers are used up to 80%, total laboratory automation up to 43% in clinical chemistry and immunology, and manual tests in all sorts of the test. There are placed in single lab or two and three labs above the ground, which are all in semi-open lab. There is some correlation with the number of specimens and the number of lab people depending on the number of hospital beds. Laboratory environment shows that work distance is good, but evacuation path width, visibility, separation of staff area from automatic analyzer, and equipment installations are needed to have more spaces and gears. Most of the infection controls are equipped with mechanical ventilation, air-conditioning, washbasin and wastewater separation, BSC installation and negative pressure lab room. Implications: Although the laboratory space area is calculated considering the number of hospital beds, type of tests and number of staff, hospital's expertise and the samples numbers per year should be taken into account in the planning of the hospital.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.6
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• pp.687-698
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• 2018

Objective: This study examined the characteristics of suicidal attempters, including pre-hospital patients and those who visited the emergency department. Methods: Suicidal attempters who had been reported to the 119 call center were selected between July 2015 and June 2016. Sex, age, place, methods of suicidal attempt, season, time, and suicide success rate were reviewed in the fire center records. Results: A total 961 suicide attempters were enrolled. Among them, 53.6% were males who had an approximately 2.6 times higher mortality than that of females (9.2%). The most preferred place to commit suicide was the home in both sexes (68.0% in male, 82.8% in female) and the most preferred methods was drug intoxication, particularly pesticide. The method with the highest mortality was hanging and the lowest was self-harm. The season of the highest mortality was spring. The success of suicide and the time variation were similar. Most of the un-transferred patients also selected fatal suicide attempts compared to transfer patients. Conclusion: Unlike previous studies, this study includes information on un-transferred patients. Overall, the probability of death was highest as more than 50 years men chose hanging as a method, which had an influence on the un-transferred patients group.

• Korean Journal of Heritage: History & Science
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• v.33
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• pp.274-289
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• 2000

Koryo Dynasty has greatly effected the meat eating practice in Korea. And by focusing on this period, this paper has in vestigated how this practice influenced and effected our meat eating culture. The 'Orders to Prohibit Butchery' written on Koryo's history books were to encourage stockbreeding rather than to follow the Buddhist policy they followed. By encouraging stockbreeding, they wanted to promote the usage of cattle in farming and thus increasing agriculture industry as a whole. Nonetheless, records show that hunting was permitted to a certain degree. And this allowed the civilians to depend their meat supply from hunting and for the fire field farmers to capture wild animals that harmed their crops. Moreover, through 'Kiwujae' (Kiwujae - a shamans service to pray for rain / ritual (praying) for rain.), we could see that earlier part of Karyo's rituals and ceremonies followed the Buddhist tradition while the latter followed the Shamanism tradition. Perhaps this was the result of allowing 'meat' for the service offerings. As Shamanism could be considered as a religion that allowed 'meat', prevalence of Shamanism was promoting meat-eating at mess(after these rituals and ceremonies that offered food (meat inclusive) to their guardian or god, the civilians would dine together.). In relation, this public eating practice slowed down the progress for storage technique. Therefore, meat-eating was developed through public and mass dining rather than through the form of family or private. On this account, we can safely regard meat-eating practice as a 'public event'. On the other hand, the history of castration is not so long in Korea. And the purpose of such practice was to use the stock for farming rather than to yield high quality meat. It is known that Mongol in Koryo period has greatly influenced meat cooking in Korea. And the exemplary dish is the 'tang' (tang - kind of soup. However less creamy, clearer broth and with more ingredients than soup.). However, the tang we ate in everyday life had the same cooking method as the tang we offered for services. Moreover, since we did not use castrated animals for our offering as the Mongolians, we must not have been greatly influenced by them. But if so, perhaps the influences would have been limited to the nobility.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.43-47
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• 2019

Developed countries are operating an in-depth database in motor vehicle crashes nationwide. They do not rely solely on the police investigation reports that are responsible for motor vehicle crashes in each country but are developing into a useful database by expanding the categories of data through more indicators addition. In Korea, after implementing comprehensive measures to reduce traffic accident deaths in 2013, the medical centers participated in establishing the actual accident investigation system, which was called as the Korean In-Depth Accident Study (hereinafter KIDAS). This KIDAS database included more in-depth indicators as the types of accidents, types of vehicles, the injury severity, adequacy of safety devices, seating position of passengers. Although there are difficulties in establishing an actual accident investigation system including data collection due to various restrictions, if the system can cooperate with each other such as medical centers, insurance companies, police, fire and rescue services, towing companies, and car repair shops in the future, It would be expected to contribute to the development of safer vehicle, treatment system and traffic safety policy that lower the injury severity of occupant in the event of a motor vehicle crashes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.3
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• pp.435-440
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• 2020

The application of the unmanned vehicles in various fields has been attracting attention, and the development of a service utilizing unmanned vehicles has been proceeding. As the service market using the unmanned vehicles rapidly increases, the demand for the development of software for performing the mission with unmanned vehicles is increasing. In particular, as the demand for unmanned vehicle utilization services for public missions such as fire detection, mail delivery, and facility management increases, the importance of developing mission software for unmanned vehicle is increasing. To develop common mission software, architecture design should be made so that unmanned vehicle service provider can easily develop software using reusable libraries or functions through analysis commonly required by various public institutions. In this paper, we discuss the research trends of mission software for public mission unmanned vehicles. In addition, the architecture design of developing formal mission software is proposed. Finally, we propose a data transfer architecture between mission software and data platform.