• Journal of Internet Computing and Services
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• 제22권6호
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• pp.151-162
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• 2021

Steganography is an advanced technique that hides secret messages by transforming them into subtle noise and spreading them within multimedia files such as images, video and audio. This technology has been exploited in a variety of espionage and cyber attacks. SNS messenger is an attractive SNS Service platform for sending and receiving multimedia files, which is the main medium of steganography. In this study, we proposed two noble steganography communication techniques that guarantee the complete reception rate through the use of thumbnail images in the SNS messenger environment. In addition, the feasibility was verified through implementation and testing of the proposed techniques in a real environment using KakaoTalk, a representative SNS messenger in south korea. By proposing new steganography methods in this study, we re-evaluate the risk of the steganography methods and promoted follow-up studies on the corresponding defense techniques.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제23권5호
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• pp.199-206
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• 2023

In this paper, the current status of domestic radio use was compared with foreign countries such as the UK and the US. As a result of the comparison, it was found that the radio reach in both the UK and the US was very high at around 90%, but in Korea it was found to be very low at 21.7%. In addition, in the UK and the US, radio broadcasting is recognized as an important medium for delivering disaster warning messages in the event of a disaster, but in Korea, the importance of radio broadcasting in disaster situations was assessed at 0.7%, confirming that its importance is being overlooked. And the measures to increase the domestic radio broadcasting usage rate are 'Improving service quality such as expanding radio reception coverage', 'Awareness of the importance of radio broadcasting as a disaster warning medium', 'Introduction of digital radio' and 'Introduction of FM radio data broadcasting'. are presented.

• Journal of Advanced Navigation Technology
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• 제28권1호
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• pp.123-128
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• 2024

When mid-span spectral inversion (MSSI), which inverts the propagated wave into phase-conjugated wave in the middle of the entire transmission distance, is combined with dispersion-managed link, it is very effective in compensating for the wavelength division multiplexed (WDM) signal distortion due to chromatic dispersion and nonlinear effects. In this MSSI combined dispersion-managed link, the shape of the dispersion map, channel data rate, channel wavelength and wavelength spacing, etc. affect the compensation and, consequently, determine the transmission distance and capacity of the WDM signal. In this paper, the compensation according to the extinction ratio of the return-to-zero (RZ) pulse that constitutes the WDM signal in the MSSI combined distributed control link was numerically analyzed. As a result of the simulation, it was conformed that the extinction ratio to obtain the best compensation should be determined depending on the shape of the dispersion map and the size of the residual dispersion per span, which determines the specific shape of the dispersion map. These results show a significant difference from the results in a general optical transmission system, where as the extinction ratio increases, the power difference between the '1' and '0' signals increases, thereby improving reception performance.

• Journal of Korean Society of Environmental Engineers
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• 제34권10호
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• pp.656-663
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• 2012

After the construction of waterworks automatic meter reading with 15 mm diameter digital water mater with magnetoresistance sensor developed in this study at 96 households of apartment complexes located in Incheon-City B-Gu S-Dong, the feasibility of field application of waterworks automatic meter reading was evaluated. The field application of waterworks automatic meter reading was performed from July to December in 2011, and average reception rate was as low as 84.6% due to the instable wibro networks, the existence of communication blackout and temporary malfunction of router. After the extraction of 10 households with one to five residents out of 96 households by using stratified random sampling method and analysis of domestic water use, it was found that domestic water use was significant at August and showed a decreasing trend at September, followed by increase in domestic water use at November and decrease in domestic water use at December. This phenomenon should be attributed to weather factors (temperature, humidity, etc.), which significantly affected domestic water use. Similar trend in domestic water use in terms of weather factors was obtained in case of Liter per capita day of water use after the extraction of 30 households out of 96 households by using stratified random sampling method. After analysis of Liter per capita day for 96 households, single residents increases resulted in reduction of domestic water usage by about 14% of Liter per capita day. These results might be due to the fact that domestic water usage such as laundry, beverages, catering, cleaning, etc. should be required for even the household with one resident, whereas domestic water usage for those common utilization can be significantly saved for the household with more than one resident.

• Journal of Acupuncture Research
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• 제27권4호
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• pp.147-178
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• 2010

Objectives : This study was to propose the improved instruction for authors and research ethic regulations by the comparative analysis of those of the domestic journals, for the purpose of enhancing the citation rate of Journal of Korean Acupuncture and Moxibustion Society. Methods : Narrative review method was used for comparatively analyzing instruction for authors of 34 domestic journals, especially focused on how to write a reference. Thereafter, in order to elucidate the drawbacks of current instruction for authors and research ethic regulations of the acupuncture and moxibustion society, the well prepared instructions and research ethic regulations was selected from them, which were compared with the present instructions for authors and research ethic regulations of the acupuncture and moxibustion society. Results : As a result of the comparative analysis of instruction for authors in the 34 domestic journals, style for references was based largely on that of National Library of Medicine and vancouver at the same time. The number of reference was limited according to types of writings. for example, the original article and case report was frequently limited to 40 and 20 references respectively. Authors were mostly listed up to six. If there are more, the first three or six authors were listed with 'et al'. it was generally recommended that using abstracts as references should be avoided and References to papers accepted but not yet published should be designated as 'in press' or 'forthcoming', and that the names of journals should be set in italics and abbreviated according to the List of Journals Indexed for Medline (formerly Index Medicus) published by the National Library of Medicine or koreanmed or WHO-IST, etc. In addition, citation of electrical literature, English writing of reference and obligational citation of more than two articles in the journals were encouraged. In consequence of comparison between well prepared instructions and research ethic regulations of the selected journals and those of current instructions for authors and research ethic regulations of the acupuncture and moxibustion society, the followings were needed to be added or revised. 1. Requirements for case reports were not mentioned. 2. Reporting Guidelines for Specific Study Designs were not included. 3. Previous Orthography of herbal prescription should be revised. 4. Orthography of authors and guidelines for writing article constituents such as title, abstract, introduction, method, statistics, results, discussions were not presented. 5. How to write a reference was so simplified. 6. Definition of Research Ethical Misconduct was omitted and establishment, management and members of committee for research ehtics were not mentioned, 7. Information, reception and investigative procedures of Research Ethical Misconduct was not specified. Conclusions : For the development of Journal of Korean Acupuncture and Moxibustion Society, apporopriate revision of the instruction for author and research ethic regulations should be made based upon the above findings. English writing of reference were believed to be one of the alternatives enhancing citation rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제11권6호
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• pp.2118-2123
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• 2010

Korean individual occupational exposure control is focused on the retrospective service to the over-exposed person by the reading of personal dosimeter. Since the radiophamaceuticals using in the nuclear medicine department are uncontained radiation sources, the potential exposure at working environment is very high. Moreover, a patient remains radioactive for hours or even days after the administration of a radiopharmaceutical for diagnosis or treatment. Thus, the proper working environmental exposure control must be established and executed to protect not only the affiliated employees, but also guardians accompanying patients and temporarily visiting public from the exposure by the patients. Japanese radiation protection law regulates working environmental radiation exposure by regularly measuring and filing the environmental dose for years. This study was aimed at measuring working environmental radiation dose in the nuclear medicine department of an university hospital located in Daejeon, Korea. We measured the accumulation radiation dose in air at 8 locations in the nuclear medicine department by using the same method as in Japan with glass dosimeters. The highest dose rate, 0.23 mSv per month, was measured at the waiting room, and the second one is at reception desk. Even though the doses were lower than the Korean constraint dose rate (0.3 mSv/week) at the boundary of the radiation controlled area, it was over the dose limit of public (1 mSv/y) and environment (0.25 mSv/y). Conclusionally, it was found that the new or additional procedure was necessary to less the exposure dose to the receptionist and guardians by the environmental radiation dose in the nuclear medicine department.

• Journal of the Korea Society for Simulation
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• 제17권2호
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• pp.21-29
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• 2008

The High Level Architecture(HLA) specifies a framework for interoperation between heterogeneous simulators, and Run-Time Infrastructure(RTI) is a implementation of the HLA Interface Specification. The Data Distribution Management(DDM) services, one category of IEEE 1516 HLA/RTI management services, control filters for data transmission and reception of data volume among simulators. In this paper, we propose design concept of DDM and show its implementation for light-weighted RTI. The design concept of DDM is to minimize total amount of message that each federate and a federation process generate using the rate of RTI service execution. The design of our proposed DDM follows that a data transfer mechanism is differently applied as the rate of RTI service execution. A federate usually publishes or subscribes data when it starts. The federate constantly updates the data and modifies associated regions while it continues to advance its simulation time. Therefore, the proposed DDM design provides fast update or region modification in exchange of complex publish and subscribe services. We describe how to process the proposed DDM in IEEE 1516 HLA/RTI and experiment variable scenarios while modifying region, changing overlap ratio, and increasing data volume.

• Journal of Broadcast Engineering
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• 제9권4호
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• pp.411-423
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• 2004

In Korea, Eureka-147 DAB (Digital Audio Broadcasting) temporarily decided as the standard system for digital audio broadcasting was evolved into DMB (Digital Multimedia Broadcasting) to complement the technical vulnerability in mobile reception of terrestrial DTV. According to introducing video service in T-DMB (Terrestrial DMB), 'Terrestrial DMB Experimental Broadcasting for Video Service', a national project of the MIC (Ministry of Information and Communication), was done for verifying the possibility of video service via T-DMB. The main objective of the project is computing the effective field strength and coverage for making a plan to build T-DMB broadcasting network and developing transmitting and receiving equipment. In case of digital broadcasting, it is absolutely essential to measure BER (Bit Error Rate) and electric field strength in order to evaluate coverage and quality of received signal. In this paper, we implement an integrated mobile measurement system for T-DMB. For this purpose, we propose efficient data structure and algorithm for BER measurement. By adding GPS (Global Positioning System) and electric field strength measurement parts into BER measurement part, we complete the integrated mobile measurement system, and then verify it by experiments and field tests. The developed system was used in a national project, 'Terrestrial DMB Experimental Broadcasting for Video Service' and measurement results will be used as fundamental data for building T-DMB broadcasting network.

• KIPS Transactions on Computer and Communication Systems
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• 제3권8호
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• pp.261-270
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• 2014

As Internet traffic increases recently, much effort has been put on improving the performance of a web server. In addition to hardware side solutions such as replacement by high-end hardware or expansion of the number of servers, there are software side solutions to improve performance. Recent studies on these software side solutions have been actively performed. In this paper, we identify performance degradation problems occurring in a conventional TCP networking reception process and propose a way to solve them. We improve performance by combining three kinds of existing methods for Linux Networking Performance Improvement and two kinds of newly proposed methods in this paper. The three existing methods include 1) an allocation method of a packet flow to a core in a multi-core environment, 2) ITR(Interrupt Throttle Rate) method to control excessive interrupt requests, and 3) sk_buff data structure recycling. The two newly proposed methods are fd data structure recycling and epoll_event data structure recycling. Through experiments in a web server environment, we verify the effect of our two proposed methods and its combination with the three existing methods for performance improvement, respectively. We use three kinds of web servers: a simple web server, Lighttpd generally used in Linux, and Apache. In a simple web server environment, fd data structure recycling and epoll_event data structure recycling bring out performance improvement by about 7 % and 6%, respectively. If they are combined with the three existing methods, performance is improved by up to 40% in total. In a Lighttpd and an Apache web server environment, the combination of five methods brings out performance improvement by up to 36% and 20% in total, respectively.

• Korean Journal of Clinical Laboratory Science
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• 제44권2호
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• pp.66-74
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• 2012

Test turnaround time (TAT) is the lead time from reception to reporting. In the complete blood cell count (CBC), 4 units of the XE-2100 (Sysmex Corp., Japan) processed around 80% of quantity, 1 unit of the LH-780 (Beckman-Coulter Incorp., USA) processed around 10% and 1 unit of ADVIA-2120 (Siemens AG, Munich, Germany) processed around 10%. We analyzed the change in the TAT for the CBC for over 7 years, from January of 2005 to December of 2011. The delta check made alterations of delta to WBC, hemoglobin, hematocrit, platelet and metamyelocyte, however, did not made them to band neutrophil, eosinophil, basophil and monocyte. The panic value check made alterations of panic value to hemoglobin, hematocrit, platelet and monocyte. In the criteria of currently slide review, LH-780 and ADVI-2120 analyzers prepared suspect flags of "Blast, Imm NE2, Immature granulocyte, Imm NE1, Left shift, Variant lymphocyte, Atypical lymphocyte, Platelet clumps and NRBC". The New slide review in the XE-2100 analyzer altered the preparations of a smear slide more than a "Platelet clumps flag(${\geq}200unit$), a single flag excluding the "Platelet clumps flag (${\geq}250unit$) and a multiple flag (${\geq}200unit$)". Also, below the 240 unit, medical technologists prepared manual slides selectively according to their evaluations. The automatic reporting rate was 33.4% without alterations, whereas it was 41.0% without alterations, and was thus improved by 7.6%. The slide review rate was 15.2% before using the Q-flag limit, whereas it was 12.1% for a reduce 3.1%. TAT was 45 minutes without the creation alterations of the delta and panic value checks, whereas it was 35 minutes after making alterations of the delta and panic value checks and thus was shortened by 10 minutes. We came to the conclusion that the establishment and operation of delta and panic value checks and slide review criteria suitable for laboratory environment can reduce unnecessary smear slides, re-checking, re-sampling, re-testing, telephone inquiries and concentrated workloads during specific times of the day.