• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.515-517
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• 1993

Dispatcher's Training simulation function are network analysis, power system modeling, supervisory control, and system security assessment. This function provides hand-on training for power dispatchers for operation of the nation control center in the future, it needs interface between simulator and expert system. This paper introduces DTS function which is adopted in the Central Load Dispatching Office.

• Anxiety and mood
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• v.2 no.1
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• pp.33-38
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• 2006

Objectives : Since prostitution is multitraumatic phenomena, it is known that most women in prostitution have symptoms of posttraumatic stress disorder (PTSD) and other mental illness. In Korea, new anti-prostitution law launched in the year of 2004 imposes protecting prostituted victims at government-supported shelter. The objective of this study was to compare the mental symptoms, especially PTSD features of women who escaped from prostitution with those of control subjects. Methods : We assessed 113 ex-prostituted women who live in shelter for 8 months on the average and 65 normal control subjects. Demographic data, questionnaire for sleep, physical illness, smoking, alcohol and drug use, Stress Response Inventory, Davidson Trauma Scale (DTS), Impact of Event Scale-Revised (IES-R) were used. Results : Ex-prostituted women had significantly higher scores of DTS, IES-R, stress related responses, sleep problems, smoking problems, and alcohol problems than control group. Age and duration of sex trade of the subjects were significantly correlated with the severity or frequency of PTSD symptoms. The degree of smoking, alcohol drinking and sleep problems were also significantly correlated with the PTSD symptoms. Conclusion : These results suggested mental symptoms did not disappear even after women escaped from prostitution.

• The Journal of the Acoustical Society of Korea
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• v.30 no.6
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• pp.337-343
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• 2011

With commencing trial 3D digital broadcasting, the studies on next generation digital broadcasting technology for coming UHDTV era is being actively progressing. In this paper, I propose surround audio formats for next-generation digital TV broadcasting, along with comparative study of major surround audio formats in use or under development. I did comparative study on current major competing surround formats such as Dolby True HD and DTS HD MA, along with NHK proposed 22.2 channel surround format for UHDTV system. Upon this comparative study and our housing situation consideration, I propose lossy compression 3D surround 7.1 channel surround format along with loosless 2.0 and 4.0 hi-fi format as next generation digital TV broadcasting standard. In lieu with this, I also propose transmitting binaural 2 channel audio data as sub-audio. It will give holographic sound experience when properly processed with individual HRTF (Head Related Transfer Function) with headphone. The table for data rate of each proposed audio format is also presented.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1100-1109
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• 2006

In this study, two different technologies which can measure temperature simultaneously at many points are introduced. One is to use a thermal sensor cable that is comprised of addressable thermal sensors connected in parallel within a single cable. The other is to use an optic fiber with Distributed Temperature Sensing (DTS) system. The difference between two technologies can be summarized as follows. A thermal sensor cable has a concept of 'point sensing' that can measure temperature at accurate position of a thermal sensor. So the accuracy and resolution of temperature measurement are up to the ability of the thermal sensor. Whereas optic fiber sensor has a concept of 'distributed sensing' because temperature is measured by ratio of Stokes and anti-Stokes component intensities of Raman backscatter that is generated when laser pulse travels along an optic fiber. It's resolution is determined by measuring distance, measuring time and spatial resolution. The purpose of this study is that application targets of two temperature measurement techniques are checked in technical and economical phases by examining the strength and weakness of them. Considering the functions and characteristics of two techniques, the thermal sensor cable will be suitable to apply to the assessment of groundwater flow, geothermal distribution and grouting efficiency within 300m distance. It is expected that the optic fiber sensor can be widely utilized at various fields (for example: pipe line inspection, tunnel fire detection, power line monitoring etc.) which need an information of temperature distribution over relatively long distance.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.4
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• pp.205-212
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• 2017

Linux Foundation has announced a real-time kernel, called Zephyr, for IoT applications recently. Zephyr kernel provides synchronous and asynchronous IPC for data communication between threads. Synchronous IPC is useful for programming multi-threads that need to be executed synchronously, since the sender thread is blocked until the data is delivered to the receiver thread and the completion of data transfer can be known to two threads. In general, 'IPC execution time' is defined as the time duration between the sender thread sends data and the receiver thread receives the data sent. Especially, it is important that 'IPC execution time' in the synchronous IPC should be fixed in real-time kernel like Zephyr. However, we have found that the execution time of the synchronous IPC in Zephyr kernel increases in proportion to the number of threads executing in the kernel. In this paper, we propose a method to implement a fixed time synchronous IPC in Zephyr kernel using Direct Thread Switching(DTS) technique. Using the technique, the receiver thread executes directly after the sender thread sends a data during the remaining time slice of the sender thread and we can archive a fixed IPC execution time even when the number of threads executing in the kernel increases. In this paper, we implemented synchronous IPC using DTS in the Zephyr kernel and found the IPC execution time of the IPC is always 389 cycle that is relatively small and fixed.

• Journal of KIISE:Software and Applications
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• v.32 no.11
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• pp.1136-1146
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• 2005

Fingerprint classification is useful in an automated fingerprint identification system (AFIS) to reduce the matching time by categorizing fingerprints. Based on Henry system that classifies fingerprints into S classes, various techniques such as neural networks and support vector machines (SVMs) have been widely used to classify fingerprints. Especially, SVMs of high classification performance have been actively investigated. Since the SVM is binary classifier, we propose a novel classifier-combination model, multiple decision templates (MuDTs), to classily fingerprints. The method extracts several clusters of different characteristics from samples of a class and constructs a suitable combination model to overcome the restriction of the single model, which may be subject to the ambiguous images. With the experimental results of the proposed on the FingerCodes extracted from NIST Database4 for the five-class and four-class problems, we have achieved a classification accuracy of $90.4\%\;and\;94.9\%\;with\;1.8\%$ rejection, respectively.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.549-555
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• 2005

To evaluate the posterior and anterior restoration of polymeric dental restorative composite (PDRC), PDRC was prepared using a silica filler treated by heat at various temperatures. Compressive strength (CS) and diametral tensile strength (DTS) values were investigated to study the effect of a heat-treated silica on the mechanical properties of PDRC using the recommended dental specifications. Both the particle size and specific volume of silica were decreased upon increasing the heat treatment temperature. CS and DTS values of PDRC containing a heat-treated silica showed 1.2 and 1.3 times, respectively, higher than that of the PDRC containing a neat silica. Also, it was found that the lower heat treatment temperature, the better mechanical properties of PDRC were observed because there was less agglomeration between silica particles. Specially, PDRC using a silica treated at $600^{\circ}C$ showed superior mechanical strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.21-24
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• 2008

This research verifies efficiency of Beam-Slab connection with Precast Prestressed Concrete Slab System of WAffle Shape(WAS) which solves problems of double-T system(DTS). Specimen is produced in Precast Concrete factories and is made in a way that WAS is layed across inverted T beam(ITB) and then it is filled with packing. After casting topping concrete into the specimen, curing is carried out. Variable are width of shear key and packing. The analysis is carried out in comparison between displacement and strength of Beam-Slab connection of specimen. The variable is not a effect in joint efficiency. Consequently, it may plans at the minimum with of shear key that packing is easy, will not affect strength.

• Korean Journal of Dental Materials
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• v.44 no.1
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• pp.69-77
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• 2017

The aim of this study was to investigate the effects of chitosan powder addition on the strengthening of conventional glass ionomer cement. Two types of chitosan powders with different molecular weight were mixed with conventional glass ionomer cement (GIC): low-molecular weight chitosan (CL; 50~190 kDa), high-molecular weight chitosan (CH; 310~375 kDa). The chitosan powders (CL and CH) were separately added into the GIC liquid (0.25-0.5 wt%) under magnetic stirring, or mixed with the GIC powder by ball-milling for 24 h using zirconia balls. The mixing ratio of prepared cement was 2:1 for powder to liquid. Net setting time of cements was measured by ISO 9917-1. The specimens for the compressive strength (CS; $4{\times}6mm$), diametral tensile strength (DTS; $6{\times}4mm$), three-point flexure (FS; $2{\times}2{\times}25mm$) with flexure modulus (FM) were obtained from cements at 1, 7, and 14 days after storing in distilled water at $(37{\pm}1)^{\circ}C$. All mechanical strength tests were conducted with a cross-head speed of 1 mm/min. Data were statistically analyzed by one-way ANOVA and Tukey HSD post-hoc test. The mechanical properties of conventional glass ionomer cement was significantly enhanced by addition of 0.5 wt% CL to cement liquid (CS, DTS), or by addition of 10 wt% CH (FS) to cement powder. The CL particles incorporated into the set cement were firmly bonded to the GIC matrix (SEM). Within the limitation of this study, the results indicated that chitosan powders can be successfully added to enhance the mechanical properties of conventional GIC.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.358-364
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• 2022

The Inter Communication System for avionics is in charge of processing all voice signals that internal calls between Pilot and Co-pilot, internal calls between Pilots and Crews, external calls through communication equipment such as Ultra/Very High Frequency Receiver/Transmitter(U/VHF RT), audio signal monitoring for navigation and mission equipment such as VHF Omnidirectional Range/Instrument Landing System(VOR/ILS), Tactical Air Navigation(TACAN), audio signal output for voice recording to Flight Data Recorder(FDR) and Data Transfer System(DTS), and warning/caution audio signal generate about the status and threat of aircraft. Because Inter Communication System for avionics is sensitive to noise in the case of analog audio signals, a redundant design that can protect audio signal from electromagnetic noise inside/outside of aircraft is required for the mission of pilots and crews. In this paper, Normal/Back-up operation mode and redundancy design plan based on digital method for the redundancy of the digital Inter Communication System for avionics and manufacturing, verification results are described.