• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.31-39
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• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Progress in Medical Physics
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• v.21 no.3
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• pp.239-245
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• 2010

The purpose of this study is to comprehensively compare and evaluate the characteristics of image quality for digital mammography systems which use a direct and indirect conversion detector. Three key metrics of image quality were evaluated for the direct and indirect conversion detector, the modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), which describe the resolution, noise, and signal to noise performance, respectively. DQE was calculated by using a edge phantom for MTF determination according to IEC 62220-1-2 regulation. The contrast to noise ratio (CNR) was evaluated according to guidelines offered by the Korean Institute for Accreditation of Medical Image (KIAMI). As a result, the higher MTF and DQE was measured with direct conversion detector compared to indirect conversion detector all over spatial frequency. When the average glandular dose (AGD) was the same, direct conversion detector showed higher CNR value. The direct conversion detector which has higher DQE value all over spatial frequency would provide the potential benefits for both improved image quality and lower patient dose in digital mammography system.

• Korean Security Journal
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• no.46
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• pp.63-86
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• 2016

The object of this study is to propose a study on the Private Investigator usage for Cyber Crime. The latest trend of cyber crime is being evolve in sophisticated and complex way over the global, like internet fraud, cyber gambling, hacking and etc. Hence national investigative authority mobilize high specialized skills and method of criminal investigation by each nation. But it is hard to respond in rapid and effective way because of propoor, distribution of group and insufficient of related legal system. Already in other countries, not considerable amount of services are given to private investigators in detection and tracking part which is inefficient by nation. So it has significantly meaningful to compensate the defect and study about private investigator usage as companion of cooperation policing for effectively respond to cyber-crime. The way to effectively deal with the cyber-crime is reevaluate meaning of partnership policing and need of private investigator usage. Also it is to analyze the main issue about introduction of a system and suggest the effective way of introduction. First, legislation of private investigator usage which is based upon partnership policing should be made up. Moreover, to establish the range of private investigator's business and enhance the reliability, it is to propose introduction of leading professional global certificate and license system with sufficient education and test. We are expecting introduction of private investigator usage can improve efficiency of investigation and promote effective countermeasures of cyber-crime.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.28-37
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• 1996

Benzidine, an aromatic amine used primarily in the manufacture of azo dyes, is recognized as a urinary bladder carcinogen in humans. In rats, mice, and hamsters, chronic exposure to benzidine resulted in tumors of the liver. The present study was undertaken to suggest analyzing the metabolites of benzidine with the optimal condition, identify the metabolites of benzidine, and observe time variance of the metabolites in the isolated perfusated rat liver. N-acetylbenzidine was synthesized by acetylation of benzidine with acetic anhydride and separated by thin layer chromatography(TLC) and high performance liquid chromatography(HPLC). To analysis benzidine and the metabolites of benzidine, HPLC operating condition has been optimized by means of preliminary experiment. The mobile phase consisted of acetonitrile(37%) in phosphate buffer, flow rate maintained at 1.0 ml/min. Optimal detective conditions were electrochemicaldetector(ECD) at 0.75 V for benzidine and N-acetylbenzidine and ultravioletdetector(UVD) at 287 nm for N,N'-diacetylbenzidine. The separation system was composed of a guard column and a separation column(Polymer C18, $4.6{\times}250cm$) at a temparature of $40^{\circ}C$. The perfusion system was equilibrated for 30 minutes before addition of benzidine to the perfusate. Samples of the perfusate were collected at time intervals(0, 10, 20, 30, 60, 90, 120 min) during the 2 hour perfusion. Before analyzing samples by HPLC/ECD/UVD, samples had been treated with sep-pak. Samples of perfusate analyzed by HPLC/ECD/UVD and the metabolites of benzidine in the isolated perfused rat liver were N-acetylbenzidine and N,N'-diacetylbenzidine. Benzidine metabolized over 60% during the initial 30 minutes of perfusion, extensively by 1 hour, and was undetectable in the perfusate. N-acetylbenzidine increased by 30 minutes of perfusion, declined. N,N'-diacetylbenzidine increased the 0-90 minutes period, remained constant during the 90-120 minutes period.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.187-194
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• 2020

The purpose of this study is to examine the effect of police investigation environment on perception toward legalization of private investigation. To enhance the completeness, this study conducted a survey on police officers in service and analyzed the survey data through statistical technique. The results for examination on how police investigation environment influence on perception toward legalization of private investigation were as follows. When the 'work burden from long-term cold case' composing the police investigation environment is high, the police officer highly evaluated the growth potential of private investigation, showed positive perception toward private investigation market, and showed intention for re-employment at private investigation agency after retirement. When the police officer experiences more difficulties from 'investigation other than criminal case', the police officer highly evaluated the growth potential of private investigation and showed intention for re-employment at private investigation agency. In addition, when the police officer thinks that there are a lot of difficulties for "Limited investigation on specialized area", the police officer showed positive perception toward growth potential of private investigation and private investigation market. In addition, police investigation environment showed significant result on legalization of private investigation. The result also verifies that as the difficulty of crime investigated by the police is getting higher quantitatively and qualitatively, it is necessary to introduce private investigation system which is specialized and able to investigate for a long time. This study hopes that this study result would be utilized as the grounds in signing the bill for introducing the private investigation system.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.289-299
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• 2009

This study set out to analyze the perceptions of investigative police officers and division police officers regarding Police Investigation Specialization, which had been in effect for four years, identify the problems, and search for alternative policies. The results led to the following alternative policies; first, the communication among the members should be facilitated by trading the jobs between investigative policemen and division members in certain percentage regularly, integrating job education and special work, and developing diverse support programs for detective activities to provide them with opportunities to experience and understand investigation. The second suggestion concerns the investigation members' morale. There should be a range of measures to boost their moral such as allocating separate budget and personnel to support the investigation department and the treatment of major criminal and civil cases, giving each investigation team an office and investigation room to improve their working environment, readjusting the promotion ratio of Police Investigation Specialization to introduce a promotion system proper for each investigation's characteristics. The third suggestion is to secure job efficiency. It's required to reinforce the current short-term specialized education program to bring up practical and professional investigators, open the certification exam of professional investigators to all members so that every policeman can have their abilities recognized and approved as long as they have the demanded capabilities, and create a system of shedding off the members idle at work by reflecting low performance records when evaluating the members to decide who to dismiss from Police Investigation Specialization. And finally, it's important to divide duties rationally. The rationality of duties division can be guaranteed by setting the guidelines for direct handling for the team leader to help him devote himself to his duties, defining objective criteria of measuring investigation workload, and creating devoted systems and teams for simple and small accidents so that experienced investigators can deal with high-profile cases.

• Korean Security Journal
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• no.17
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• pp.15-31
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• 2008

This study aims to analysis and measure on the private security for the academic directivity and security industry for the market directivity in Korea. For this study we compare and analysis the curriculum of 15 universities in Korea and the papers which were published on "Korean Security Science Review" that is a report in a professional private security. In conclusion, 269 subjects are used as instructional materials in 15 universities, thus 103 subjects for the private security and 60 for the leisure sports and first-aid treatment, 46 for the social science, 30 for the martial arts and shooting, 16 for the secretary affairs, 14 for the foreign languages. Regarding scientistic papers, 45.7% of papers for the private security of all and 14.6% for the public security, 14.6% for the criminal, and 11.6% for the terror etc. But there are any papers for the facilities guard or security in spite of the facilities guard is pivotal role in this field. The facilities guard or security, or maybe house detective, holds 80.5% of the private security market and it is important role in this industry in Korea. Besides, considering development of private security, the security market makeup the body-guard field hold 12.2%, prevention security system by censor hold 4.1%. So, this statistics show that the facilities guard lead practically the private security industry in this field, but there are any subjects for the education and any research for the paper. Thus some modification on the universities curriculum is required, also needs activity research in the facilities guard field for the development private security.

• Animal Bioscience
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• v.36 no.9
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• pp.1336-1349
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• 2023

Objective: The study was conducted to screen differentially expressed miRNAs in sows at early pregnancy by high-throughput sequencing and explore its mechanism of action on embryo implantation. Methods: The blood serum of pregnant and non-pregnant Landrace×Yorkshire sows were collected 14 days after artificial insemination, and exosomal miRNAs were purified for high throughput miRNA sequencing. The expression patterns of 10 differentially expressed (DE) miRNAs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR quantified the abundance of serum exosomal miR-192 in pregnant and control sows, and the diagnostic power was assessed by receiver operating characteristic (ROC) analysis. The target genes of DE miRNAs were predicted with bioinformatics software, and the functional and pathway enrichment analysis was performed on gene ontology and the Kyoto encyclopedia of genes and genomes terms. Furthermore, a luciferase reporter system was used to identify the target relation between miR-192 and integrin alpha 4 (ITGA4), a gene influencing embryo implantation in pigs. Finally, the expression levels of miRNAs and the target gene ITGA4 were analyzed by qRT-PCR, and western blot, with the proliferation of BeWo cells detected by cell counting kit-8 (CCK-8). Results: A total of 221 known miRNAs were detected in the libraries of the pregnant and non-pregnant sows, of which 55 were up-regulated and 67 were down-regulated in the pregnant individuals compared with the non-pregnant controls. From these, the expression patterns of 10 DE miRNAs were validated. The qRT-PCR analysis further confirmed a significantly higher expression of miR-192 in the serum exosomes extracted from pregnant sows, when compared to controls. The ROC analysis revealed that miR-192 provided excellent diagnostic accuracy for pregnancy (area under the ROC curve [AUC]=0.843; p>0.001). The dual-luciferase reporter assay indicated that miR-192 directly targeted ITGA4. The protein expression of ITGA4 was reduced in cells that overexpressed miR-192. Overexpression of miR-192 resulted in the decreased proliferation of BeWo cells and regulated the expression of cell cycle-related genes. Conclusion: Serum exosomal miR-192 could serve as a potential biomarker for early pregnancy in pigs. miR-192 targeted ITGA4 gene directly, and miR-192 can regulate cellular proliferation.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.249-254
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• 2022

With the rapid advance of the semiconductor and Information and communication technologies, remote environment monitoring technology, which can detect and analyze surrounding environmental conditions with various types of sensors and wireless communication technologies, is also drawing attention. However, since the conventional remote environmental monitoring systems require external power supplies, it causes time and space limitations on comfortable usage. In this study, we proposed the concept of the self-powered remote environmental monitoring system by supplying the power with the levitation-electromagnetic generator (L-EMG), which is rationally designed to effectively harvest biomechanical energy in consideration of the mechanical characteristics of biomechanical energy. In this regard, the proposed L-EMG is designed to effectively respond to the external vibration with the movable center magnet considering the mechanical characteristics of the biomechanical energy, such as relatively low-frequency and high amplitude of vibration. Hence the L-EMG based on the fragile force equilibrium can generate high-quality electrical energy to supply power. Additionally, the environmental detective sensor and wireless transmission module are composed of the micro control unit (MCU) to minimize the required power for electronic device operation by applying the sleep mode, resulting in the extension of operation time. Finally, in order to maximize user convenience, a mobile phone application was built to enable easy monitoring of the surrounding environment. Thus, the proposed concept not only verifies the possibility of establishing the self-powered remote environmental monitoring system using biomechanical energy but further suggests a design guideline.

• Journal of Intelligence and Information Systems
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• v.25 no.3
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• pp.89-115
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• 2019

This study was conducted to present the stylistic differences between Arthur Conan Doyle and Agatha Christie, famous as writers of classical mystery novels, through data analysis, and further to present the analytical methodology of the study of style based on text mining. The reason why we chose mystery novels for our research is because the unique devices that exist in classical mystery novels have strong stylistic characteristics, and furthermore, by choosing Arthur Conan Doyle and Agatha Christie, who are also famous to the general reader, as subjects of analysis, so that people who are unfamiliar with the research can be familiar with them. The primary objective of this study is to identify how the differences exist within the text and to interpret the effects of these differences on the reader. Accordingly, in addition to events and characters, which are key elements of mystery novels, the writer's grammatical style of writing was defined in style and attempted to analyze it. Two series and four books were selected by each writer, and the text was divided into sentences to secure data. After measuring and granting the emotional score according to each sentence, the emotions of the page progress were visualized as a graph, and the trend of the event progress in the novel was identified under eight themes by applying Topic modeling according to the page. By organizing co-occurrence matrices and performing network analysis, we were able to visually see changes in relationships between people as events progressed. In addition, the entire sentence was divided into a grammatical system based on a total of six types of writing style to identify differences between writers and between works. This enabled us to identify not only the general grammatical writing style of the author, but also the inherent stylistic characteristics in their unconsciousness, and to interpret the effects of these characteristics on the reader. This series of research processes can help to understand the context of the entire text based on a defined understanding of the style, and furthermore, by integrating previously individually conducted stylistic studies. This prior understanding can also contribute to discovering and clarifying the existence of text in unstructured data, including online text. This could help enable more accurate recognition of emotions and delivery of commands on an interactive artificial intelligence platform that currently converts voice into natural language. In the face of increasing attempts to analyze online texts, including New Media, in many ways and discover social phenomena and managerial values, it is expected to contribute to more meaningful online text analysis and semantic interpretation through the links to these studies. However, the fact that the analysis data used in this study are two or four books by author can be considered as a limitation in that the data analysis was not attempted in sufficient quantities. The application of the writing characteristics applied to the Korean text even though it was an English text also could be limitation. The more diverse stylistic characteristics were limited to six, and the less likely interpretation was also considered as a limitation. In addition, it is also regrettable that the research was conducted by analyzing classical mystery novels rather than text that is commonly used today, and that various classical mystery novel writers were not compared. Subsequent research will attempt to increase the diversity of interpretations by taking into account a wider variety of grammatical systems and stylistic structures and will also be applied to the current frequently used online text analysis to assess the potential for interpretation. It is expected that this will enable the interpretation and definition of the specific structure of the style and that various usability can be considered.