• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.171-176
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• 2000

Bioremediation of hazardous hydrophobic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), is a major environmental concern due to their toxic and carcinogenic properties. Due to their hydrophobicity, the hydrophobic organic compounds are mainly associated with the soil organic matter or nonaqueous-phase liquids. A major question concerns the relationships between biodegradation and sorption. This work develops and utilizes a non- steady state model for evaluating the interactions between sorption and biodegradation of phenanthrene, a 3-ring PAH compound, in soil-slurry systems. The model includes sorption/desorption of a target compound, its utilization by microorganisms as a primary substrate existing in the dissolved phase and/or the sorbed phase in biomass and soil, oxygen transfer, and oxygen utilization as an electron acceptor. Biodegradation tests with phenanthrene were conducted in liquid and soil-slurry systems. The soil-slurry tests were performed with very different mass transfer rate: fast mass transfer in a flask test at 150 rpm, and slow mass transfer in a roller-bottle test at 2 rpm. In the slurry tests, phenanthrene was degraded more rapidly than in liquid tests, but with a similar rate in both slurry systems. Modeling analyses with several hypotheses indicate that a model without biodegradation of compound sorbed to the soil was not able to account for the rapid degradation of phenanthrene, particularly in the roller bottle slurry test. Reduced mass-transfer resistance to bacteria attached to the soil is the most likely phenomenon accounting for rapid sorbed-phase biodegradation.

• 한국식품영양학회지
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• 제15권1호
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• pp.64-69
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• 2002

To know a degree of pollution in agricultural products cultivated around 4 unworked mines located in Chollanam-Do, we investigated a concentration of heavy metal and trace metal to provide the basic data for its residual limits. 28 samples of seven kinds of agricultural products(lettuce, onion, potato, radish, pepper, pumpkin, bean) collected from 4 unworked mines located in Chollanam-Do in 2001 were analyzed by Mercury Analyzer for mercury and Atomic Absorption spectrophotometer for Pb, As, Cd, Cu, Mn, and Zn. Hg contents were detected N.D. ∼trace level(0.01 ppm and less) and As content were detected N.D. ∼ 0.029 lpm but most of same)leE were not detected. Cd contents were detected N.D∼0.124 ppm. The results of Hg, As, Pb and Cd content showed that for all the 7 species of agricultural products studied, none have accumulated levels dangerous enough to Pose health problems. The average contents of Cu were 3.070 ∼ 7.825 ppm in bean, the Mn were 3.688 ∼23.935 ppm in lettuce ailed the Zn were 5.690 ∼21.171 ppm in bean, respectively.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.171-176
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• 2005

This paper presents a novel Intelligent-Welding-Carriage (IWC) for automation of curved block in shipbuilding. The curved block is usually used in both front and back side of the ship. In curved block root gap is big, 1-7 (mm) and inclination, 0-30 (deg). Since available conventional carriage type is limited to use below root gap of 3 (mm), only manual welding is employed in curved block. To adopt an IWC in curved block, it requires control of the welding conditions, i.e., voltage. current, weaving speed, dwell time and travel speed, with respect to root gap and inclination to achieve good welding qualify. In this paper, an IWC is developed for automization of welding operation to accommodate gap and inclination. Kinematics model and dynamics using Lagrangian formulation of the manipulator is introduced. IWC utilizes a database to perform accurate welding. The database is programmed based on numerous experimental test results with respect to gap, inclination, material, travel speed, weaving condition, voltage, and current. Finally, experimental result using PID control is addressed for verifying the trajectory tracking accuracy of end-effector.

• 간호행정학회지
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• 제20권4호
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• pp.373-382
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• 2014

Purpose: The purpose of this study was to analyze the effects of empathy, resilience and self-care on compassion fatigue in oncology nurses. Methods: The study design was a descriptive survey and questionnaires were collected from December 1 to 15, 2013. Participants were 171 oncology nurses caring for cancer patients. Data was analyzed using independent t-test, $Scheff\acute{e}$ test, one-way ANOVA, Pearson correlation coefficient and hierarchical multiple regression with the SPSS/WIN 18.0 program. Results: Seventy two percent of the participants reported a moderate to high level of compassion fatigue. Empathy was positively correlated with compassion fatigue, whereas, resilience and self-care had negative correlations with compassion fatigue. Finally, empathy, resilience, self-care and age accounted for 30% of the variance in compassion fatigue. Conclusion: Results indicate that empathy, resilience and self-care are factors influencing compassion fatigue. Therefore, it is necessary to develop and make available programs embracing personal factors in the prevention and reduction of compassion fatigue.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1995년도 제4회 학술강연회논문집
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• pp.171-175
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• 1995

Semiconductor diode lasers that can generate one watt or more of optical energy for tens of milliseconds (quasi continuous wave) are now readily available. Several researchers have demonstrated that this power level, when properly coupled, can reliably initiate pyrotechnic mixtures. This means that the initiator containing the pyrotechnic can be protected against inadvertent initiation from electromagnetic radiation or electrostatic discharge by a conducting Faraday cage surrounding the explosive. Only a small dielectric window penetrates the housing of the initiator, thereby eliminating the conductors necessitated by a bridgewire electroexplosive device. The diode laser itself, however, functions at a low voltage (typically 3 volts) and hence is susceptible to inadvertent function from power supply short circuits, electrostatic discharge or induced RF energy. The rocket motor arm-fire device de-scribed in this paper uses a diode laser, but protects it from unintentional function with a Radio Frequency Attenuating Coupler (RFAC).The RFAC, invented by ML Aviation, a UK company, transfers power into a Faraday cage via magnetic flux, thereby protecting the diode, its drive circuit and the pyrotechnic from all electromagnetic and electrostatic hazards. The first production application of a diode laser and RFAC device was by the Korean Agency for Defense Development.

• 미생물학회지
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• 제54권2호
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• pp.171-173
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• 2018

본 연구에서 이용된 Enterococcus faecium JB00008 (KACC 92186P) 균주는 전통발효식품인 청국장에서 분리되었다. 이 균주는 Escherichia coil에 대해 높은 항균활성능력을 보였다. 우리는 이 균주의 유전체의 염기 서열을 분석하였다. 유전체 초안은 500 bp 이상의 contig 34개로 조립되었으며, 크기가 2,847,295 bp이고, G + C 함량(%)는 37.84%이다. 유전체 초안에서 항균활성물질(bacteriocin) 중 하나인 enterocin과 연관된 유전자가 5개 확인되었다.

• Industrial Engineering and Management Systems
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• 제13권2호
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• pp.163-171
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• 2014

Under amazing increase in markets and certain demand on qualified service in the delivery system, global logistic optimization is becoming a keen interest to provide an essential infrastructure coping with modern competitive prospects. As a key technology for such deployment, we have been engaged in the practical studies on vehicle routing problem (VRP) in terms of Weber model, and developed a hybrid approach of meta-heuristic methods and the graph algorithm of minimum cost flow problem. This paper extends such idea to multi-depot VRP so that we can give a more general framework available for various real world applications including those in green or low carbon logistics. We show the developed procedure can handle various types of problem, i.e., delivery, direct pickup, and drop by pickup problems in a common framework. Numerical experiments have been carried out to validate the effectiveness of the proposed method. Moreover, to enhance usability of the method, Google Maps API is applied to retrieve real distance data and visualize the numerical result on the map.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.171-177
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• 2003

A project planning is one of the most important processes that determines success and failure of the project. A pre-project planning is also essential job for information system implementations at the early stage of project planning, especially for management information system like ERP. However, pre-project planning is very difficult, because lots of factors and their relationships should be considered. Pre-project planning of ERP implementation has been done by project manager's own knowledge and experiences. In this article, we propose a system that help project manager to make a pre-project plan of ERP project with case-based reasoning(CBR) framework. The proposed CBR system saves previous cases of ERP pre-project planning in the case base. Then, the system finds the best similar case with the current pre-project planning problem. Project manager can make a pre-project plan by adjusting the most similar case. From the interview with project managers, we collect some field cases of ERP implementation. We organized these cases by using XML(Extensible Markup Language), which is good for representing hierarchical information. XML gives us some flexibilities to correct and maintain cases. We make a prototype system, PPSS(Project Planning Support System) that help project manager to make a pre-project plan of ERP implementations. The object of the system is to support project manager to make a pre-project plan of ERP. We hope the result of the study can be applied to other information systems. Our research should be extended to cover other stages of project planning.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.171-175
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• 2005

Automotive parts manufacturers are doing their best to strengthen the competitiveness. They are developing a large variety of new manufacturing technologies to reduce the manufacturing cost. Combined One Body Stamping(C.O.B.S) is one of the remarkable technologies to reduce production cost. C.O.B.S makes possible to form several parts together in a process using only one die set while conventional stamping demands the same number of die sets to the number of parts. But the deformation mechanism in C.O.B.S is more complicated because the interactions between blanks. So the interaction effects should be considered in the stage of initial blank shape design. In the study, a blank design method to consider the interactions between blanks was proposed and verified through the simulations and experiments. A commercial incremental FE code, LS-Dyna, was used to simulate the C.O.B.S Process. And a reverse one step FE code, Hyper Form, was used to predict initial blank shape. The boundary conditions of the reverse one step FE analysis were determined by the proposed method.

• 한국해양공학회지
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• 제35권2호
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• pp.161-171
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• 2021

For the fatigue design of offshore structures, it is essential to understand and use the S-N curves specified in various industry standards and codes. This study compared the characteristics of the S-N curves for five major codes. The codes reviewed in this paper were DNV Classification Rules (DNV GL, 2016), ABS Classification Rules (ABS, 2003), British Standards (BSI, 2015), International Welding Association Standards (IIW, 2008), and European Standards (BSI, 2005). Types of stress, such as nominal stress, hot-spot stress, and effective notch stress, were analyzed according to the code. The basic shape of the S-N curve for each code was analyzed. A review of the survival probability of the basic design S-N curve for each code was performed. Finally, the impact on the conservatism of the design was analyzed by comparing the S-N curves of three grades D, E, and F by the five codes. The results presented in this paper are considered to be a good guideline for the fatigue design of offshore structures because the S-N curves of the five most-used codes were analyzed in depth.