• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.346-353
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• 2016

In the design conditions of some research reactors, the siphon phenomenon can cause continuous efflux of water during pipe rupture. A siphon breaker is a safety device that can prevent water efflux effectively. However, the analysis of the siphon breaking is complicated because many variables must be included in the calculation process. For this reason, a simulation program was developed with a user-friendly GUI to analyze the siphon breaking easily. The program was developed by MFC programming using Visual Studio 2012 in Windows 8. After saving the input parameters from a user, the program proceeds with three steps of calculation using fluid mechanics formulas. Bernoulli's equation is used to calculate the velocity, quantity, water level, undershooting, pressure, loss coefficient, and factors related to the two-phase flow. The Chisholm model is used to predict the results from a real-scale experiment. The simulation results are shown in a graph, through which a user can examine the total breaking situation. It is also possible to save all of the resulting data. The program allows a user to easily confirm the status of the siphon breaking and would be helpful in the design of siphon breakers.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.575-580
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• 2013

The IMU(Inertial Measurement Unit) which is the expensive equipment has been used as a special limited area, usually in measurement of posture of applying to the areas of ship, submarine, aircraft and military equipment application. However, in the current situation, MEMS AHRS technology can replace the high-priced IMU in MEMS AHRS selected application field. In this paper, wireless hull motion measurement system was suggested for measuring key elements of ship's movement such as rolling, pitching and yawing using gyro, acceleration and magnetic sensors of AHRS. In order to reduce the error such as instantaneous acceleration, effects and vibration of geomagnetic, we have adopted the sensors equipped with Kalman filtering. The Wireless hull motion measurement system using AHRS sensors was tested in actual ship and it could easily be applied in limited installation circumstances of the ship. In the future, this system can be useful in the navigation safety and marine accident analysis by using with ship equipment such as INS or VDR in the maritime.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.13-24
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• 2009

This study developed a high strength and performance concrete pavement material with low shrinkage and reflection of sunlight. Based on the literature review, a new mix-design of applying flash ash to improve the strength and performance of the concrete as well as to reduce the dry shrinkage is suggested. In addition, adding black pigment to reduce the reflection and technique of applying OAG (Optimized Aggregate Gradation) is also included. The result of the laboratory experiment indicates that the brightness and the reflection, which depends on the ratio of black pigment addition, did not deviate from the normal range. When OAG is considered for the mix-design, the strength and performance of the concrete improved greatly. In addition, the mix-design using fly ash reduced the dry shrinkage of concrete and improved the resistance to the permeation of chloride ion. Furthermore, the mix-design, which uses fly ash (25% replacement) and black pigment (3% addition) with the application of OAG, is found to be the most effective mix to reduce the shrinkage and reflection as well as improving the strength and performance of the concrete. The result of an economic analysis indicates that the initial construction cost of this proposed mix is more expensive than that of normal concrete pavement material. However, it can be more economic in the long run because the normal concrete pavement material is likely to cost more due to higher probability of maintenance and repair and higher social cost due to traffic accident, etc.

• Journal of the Korean Society of Radiology
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• v.1 no.3
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• pp.35-40
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• 2007

The purpose of this study was to investigate in S city of Chung-Nam using direction radiation Cervical spine among patient enforcing AP view, lateral view, total 113 subjects(40-year-old low)by target examine and got following as: 1) Distribution of age 14~40 years old 57 men (50.4%), woman 56subjects(49.6%)be, and age group 30~40year old 80subjects(70.8 %), 20~29year old 27subjects(23.9%). 2) It appeared most by 81subjects(71.7%) that can not know cause though traffic accident, misstep, cause ignorantness were investigated to revealed by the chronic 87subjects(77%) appeared by thing which statistical significance is with occurrence cause. 3) 20 Among whole 113subjects 20~29years old 27 subjects(23.9%), 30~40years old 80 subjects(70.8%) manifestationacute form of a disease, the chronic all high distributionsee. 4) This investigator left shoulder region pain among 39 subjects whole 113 subjects (left to direction that could know that is each main pain in 34.5 %), cervical vertebral portion upside 31 subjects(27.4%), both shoulder region pain 20 subjects(17.7%), and becomes left side scoliosis 62 subjects(54.9%)by the most frequencies appear. 5) Appeared antespondylolisthesis by all curve 48 subjects(42.5 %) in curve direction and at Systolic blood pressure from 160mmHg to all 19 subjects (before total 69 subjects (61.0 %) at 16.8 %), Diastolic blood pressures curve 31 subjects(27.4 %) by 100 mmHg appear.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.65-72
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• 2011

ENFP the flowers 66.7%, INFP 50% of the leaves was the first that showed interest. ISTP in the fragrance of the plants, the 55.6% interest in the first feeling, ENTJ's 60%, INFJ's 75%, INTJ 83.3% of the entire plant in the form of the first was said to have interest. MBTI personality types, depending on the interest portion of the plant selection for mean difference (p=0.004). Favorite types of plants, flowers, 53.7%, 32.7% fruits, vegetables, 5.4% have been selected, depending on the features your favorite plants, types of hearing means the difference (p=0.022). Select any of four kinds of flowers, plants, plants that NF 40.7%, NT 58.8% were preferred, SF a fragrant plants that were preferred by 41.8%. ST flowering plants in the 37.5%, 29.2% of the seasonal green leafy foliage was preferred. Depending on the psychological features a selection for your favorite flora also indicates a difference (p=0.038). MBTI personality types based on the four indicators in the form of leaves and flowers preferred type for accident analysis determined a feature based on the emotional type, meaning that it leaves the choice of form, and (p=0.036), determined according to the type-aware select a flower type refers to the difference (p=0.025).

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.66-73
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• 2019

Thanks to various efforts to reduce disasters by the government and the Health and Safety Authority, disasters across industries and the construction industry show their reduction trend. However, the falling disasters in the construction industry have not decreased and increased on the contrary. Especially falling disaster caused by Hanging Scaffolding is the most critical disaster which shows low occurrence frequency but is directly connected to death of worker. The working environment for Hanging Scaffolding is poor in domestic construction site. In particular, the Hanging Scaffolding workers in small construction sites are not on the safety control and management by anyone for their works. They are driven to unsafe working condition with mostly uncertified facilities which are made by themselves. Therefore, this study is focused on searching falling disaster factors from the 242 disaster cases caused by Hanging Scaffolding Work in 15 years presented by KOSHA, and trying to provide suggestions for improvement. The improvement of the method of work requires facility improvement and work due to high accident rate caused by unsafe behavior. Analysis of the case of a disaster occurring over the past 15 years shows that no disaster occurred due to problems in the order of operations presented by KOSHA. However, it was found that many accidents resulted from death caused by safety belts not being installed or attached to ropes using safety belts without following the order of work. The most important aspect of improving the work method was the installation and wearing of lifeboats and safety belts.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.781-789
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• 2019

There are frequent accidents by chemicals during laboratory experiments and pilot plant and reactor operations. It is necessary to find and comprehend relevant information to prevent accidents before starting synthesis experiments. In the process design stage, reaction information is also necessary to prevent runaway reactions. Although there are various sources available for synthesis information, including the Internet, it takes long time to search and is difficult to choose the right path because the substances used in each synthesis method are different. In order to solve these problems, we propose an intelligent synthetic path search system to help researchers shorten the search time for synthetic paths and identify hazardous intermediates that may exist on paths. The system proposed in this study automatically updates the database by collecting information existing on the Internet through Web scraping and crawling using Selenium, a Python package. Based on the depth-first search, the path search performs searches based on the target substance, distinguishes hazardous chemical grades and yields, etc., and suggests all synthetic paths within a defined limit of path steps. For the benefit of each research institution, researchers can register their private data and expand the database according to the format type. The system is being released as open source for free use. The system is expected to find a safer way and help prevent accidents by supporting researchers referring to the suggested paths.

• Journal of The Korean Association For Science Education
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• v.39 no.4
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• pp.563-571
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• 2019

The purpose of this study is to analyze the safety contents presented in high school science textbooks of the 2015 revised national science curriculum. For these, we found safety contents in the inquiries and appendices of 63 science textbooks: integrated science, science inquiry experiment, physics I, II, chemistry I, II, biology I, II, and earth science I, II. We analyzed these safety contents using six safety factors based on the seven standards for safety education. The main results are as follows: First, 81(46.0%) inquiries among 176 curriculum inquiries contain safety contents, and these contents are mainly found in chemistry textbooks, and the least in 'science inquiry experiment' textbooks. Second, safety contents are found the most in 'laboratory safety rule', followed by 'safety symbol' and 'usage of protection equipment'. Third, the safety contents of appendices are mainly in 'laboratory safety rule' and 'accident treatment'. Based on these results of this study, it is concluded that these textbooks have problems; that there is a big difference in describing safety contents in each textbook; that these safety contents are not presented in detail and that the educational effect is reduced. Furthermore, the safety symbol is not standardized. We also discussed ways to improve the safety contents of science textbooks.

• Journal of Korea Port Economic Association
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• v.25 no.2
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• pp.57-72
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• 2009

The purpose of this paper is to show the empirical measurement way of operation risk evaluation in domestic seaports for overcoming the limitations which the traditional DEA method has by using 13 Korean ports in 2003 for 4 inputs(birthing capacity, cargo handling capacity, number of coastal guard vessel, number o f coastal special guard vessel ) and 5 outputs(Export and Import Quantity, Number of Ship Calls, number of coastal accident, number of coastal crime, number of coastal pollution). Because traditional DEA method has produced the limited set of information, negative DEA mixed with tier, stratification and layering methods should be adopted. The goal of negative DEA is to set up DEA models that will place the poor operating ports on or close to the empirical frontier. The core empirical results of this paper are as follows. First, Donghae ports should benchmark the operation way of Yeasu, Busan, Woolsan ports in terms of the middle and longterm base. Second, 5 ports(ports of Taean, Yeasu, Tongyoung, Busan, Sokcho) which were revealed as the poor operating ports in Negative DEA analysis should benchmark Incheon, Woolsan, Pohan, and Donhae ports. The policy implication to the Korean seaports and planners is that Korean seaports should introduce the new methods like Negative DEA of this paper for predicting the poor operating in the ports.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.639-645
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• 2017

Application Specific Messages (ASM) have been introduced by a number of international bodies, such as the International Maritime Organization (IMO), the International Telecommunication Union (ITU) and the International Association of Lighthouse Authorities (IALA), for the purpose of resolving AIS overloading issues caused by an increasing number of ships using AIS systems. ASM communication will transmit a large amount of safety-related information at sea, including meteorological information, accident reporting, and navigational warnings. Specifically, this message transaction system is expected to be actively used for communication among ships and for ship-to-shore (4S), where VHF communication through voice was standard. In order to design a user-oriented service through standardised AIS-ASM messaging in the future, the need for analysis of this seems to be quite critical. In order to reflect users' AIS-ASM communication needs, therefore, frequently-occurring marine communication messages were analysed through a questionnaire survey conducted on 57 marine officers and 50 VTS operators. Based on the survey results, a list of key standardised messages was suggested as a reference for future AIS message development.