• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1103-1109
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• 2023

Today, as the number of audio files submitted as legal evidence increases with the proliferation of smartphones, the integrity of audio files has become an important issue. Accordingly, the purpose of this study is to explore whether the metadata and file structure of audio files recorded on Samsung smartphones can be manipulated to be identical to the original. This study was based on Samsung smartphones, the most widely used in Korea, and conducted experiments on the built-in voice recording app and the 'Easy Voice Recorder' app, which is the most popular recording app. Through the experiments of this study, it was proven that the metadata and file structure of audio files can be manipulated. Therefore, this study reveals that metadata and file structure analysis have limitations in proving the integrity when audio files are analyzed for adoption as legal evidence. They also argue for the need to develop new voice file forgery technology that does not rely on metadata and file structure analysis.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.723-729
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• 2007

The Ministry of Environment established a guide line in December 2006, "Indoor Air Quality Management guidelines in Public Facilities." As the items of the guideline, $CO_2$ (Carbon dioxide) and PM10 (particulate matter) is shown to Level 1 and 2. Therefore trains and subways are included. There are a lot of tunnels by the lay of mountains on KTX (Korean Train Express) service. HVAC (Heating Ventilating and Air-conditioning)-pressurization equipment on KTX is various functioning flaps blocking outside pressure waves. At that time, the fresh air is blocked by flap operation and the air is circulated by return air. In this study, we measured the time series of $CO_2$ and PM10 concentrations in the KTX passenger cabin during the train service of Gyongbu line (Seoul-Busan) and Honan line (Yongsan-Mokpo) from July 2006. Also, analyzed the air quality by operation of KTX HVAC-pressurization equipment in tunnel passing point. As a result, PM10 concentration was totally lower than the regulation values. However, $CO_2$ was highly correlated with several tunnels, such as Oksan-Otan, Godeung-Hyudae and Gaechak-Iijik tunnel. but, the indoor air quality of KTX train have been proved satisfy the recommendation the Ministry of Environment guidelines.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.123-132
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• 2006

In this paper, the digital video and audio system is improved so that various digital video data formats in DVD disc, and digital audio data formats through the S/PDIF ports may be decoded. It is not easy to implement all decoding functions of video and audio by a DVD processor. The special structure in audio decoding circuit is proposed in this system so as to have simultaneously almost same video and audio performance in quality. By dividing the decoding circuit separately into video and audio part, the audio quality can be dramatically improved together with supporting several audio formats and with several effects. In order to satisfy the perfect audio system to support to audio decoding formats, it is just enough to get the expensive, complicated decoder. However, it may be not easy to get this expensive decoder in near future. Therefore it is rather to adopt the downloading method by which the host should download the appropriate code into memory by detecting the corresponding audio bit streams. It is proved that this method may be efficient in the point of sharing resource of audio data for video decoding.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.592-607
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• 2006

This paper proposes a technique to select processors and hardware IPs and to map the tasks into the selected processing elements, aming to achieve high performance with minimal system cost when multitask applications with real-time constraints are run on a multicore SoC. Such technique is called to 'Hardware-Software Cosynthesis Technique'. A cosynthesis technique was already presented in our early work [1] where we divide the complex cosynthesis problem into three subproblems and conquer each subproblem separately: selection of appropriate processing components, mapping and scheduling of function blocks to the selected processing component, and schedulability analysis. Despite good features, our previous technique has a serious limitation that a task monopolizes the entire system resource to get the minimum schedule length. But in general we may obtain higher performance in multitask multicore system if independent multiple tasks are running concurrently on different processor cores. In this paper, we present two mapping techniques, task mapping avoidance technique(TMA) and task mapping pinning technique(TMP), which are applicable for general cases with diverse operating policies in a multicore environment. We could obtain significant performance improvement for a multimedia real-time application, multi-channel Digital Video Recorder system and for randomly generated multitask graphs obtained from the related works.

• Journal of Animal Environmental Science
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• v.6 no.2
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• pp.121-130
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• 2000

Pure voice characteristics of sow were analyzed to predict parturition time. These were analyzed by using oscilloscope and Sound Forge and the results showed that the voice frequency and amplitude of sow were in the range of 30∼2,500Hz and -35∼-75dB. According to the sound analysis results, the frequencies of sound appearance from farrowing sow in the farrowing pen for three days prior to delivery day and eight hours of prior to delivery day and eight hours of prior to time were around 85% and 46%, respectively of the total appearance during eight days to delivery. Forecasting of delivery time of farrowing sow using the number of sound occurrences showed a promising result such that those have been increased whenever the delivery time was approached. The forecasting success rates were 100% for both of one day and six hours prior to the actual delivery.

• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.107-116
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• 2000

Pure voice characteristics of sow were analyzed to predict parturition time. These were analyzed by using oscilloscope and Sound Forge and the results showed that the voice frequency and amplitude of sow were in the range of 30~2,500Hz and -35~-75dB. According to the sound analysis results, the frequencies of sound appearance from farrowing sow in the farrowing pen for three days prior to delivery day and eight hours of prior to time were around 85% and 46%, respectively of the total appearance during eight days to delivery. Forecasting of delivery time of farrowing sow using the number of sound occurrences showed a promising result such that those have been increased whenever the delivery time was approached. The forecasting success rates were 100% for both of one day and six hours prior to the actual delivery.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.2
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• pp.133-141
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• 2001

Purpose: Gastroesophageal reflux (GER) has been found to be the causative factors of apnea, stridor, feeding intolerance, poor weight gain, and sudden infants death syndrome (SIDS) in infants. GER is a well-described in infants and children, but only scant mention of the premature infants with GER can be found in the literature. Methods: Esophageal pH was measured during 24 hour in 21 healthy preterm infants, using a silicone microelectrode with an external reference electrode connected to a portable recorder. The mean age of the patients was $29{\pm}8$ days, mean gestational age was $30^{+5}{\pm}2^{+0}$ weeks, mean birth weight was $1,468{\pm}329$ g, mean postconceptional age was $34^{+6}{\pm}1^{+4}$ weeks and mean weight was $1,750{\pm}329$ g. We evaluated the following reflux parameters; number of acid reflux, number of long acid reflux, longest acid reflux minutes, and reflux index. Results: Pathologic GER was detected in 12 (57%) subjects and most interesting parameters are reflux index and number of episodes with a pH<4 during 24 hour (high correlation with postprandial reflux index). Reflux was not correlated to gestational age, birth weight, age, postconceptional age, weight, sex and medication of the theophylline. Conclusion: Gastroesophageal reflux is common in preterm infants, but it is usually not apparent, even with severe reflux.

• Korean journal of communication and information
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• v.60
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• pp.125-149
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• 2012

This study explores the formational process of KBS PD's professional identity in the 1970's, focusing on everyday work and workplace for program production. In terms of salary and social-cultural status, a television PD was not a desirable occupation in the 70's. Since the beginning of radio broadcasting, production of culture and education programs had been sub-categorized under Programming Division. Also, it has been claimed in several researches that in the 70's, the production of education and cultural programs had visibly grown owing to the political necessity of policy PR and campaigns, and the introduction of new broadcasting equipment and technologies for producing the mentioned political campaign programs. However, this study argues that the main force that led to such developments was the cultural practices and the production spirits of the KBS PD's. These PD's trained themselves in production workplace from the bottom by assisting film directors and learning from cameramen about the film making and post-production process. Moreover, in the transitional phase from film to magnetic tape recorder, they established themselves as main subjectivities of production by developing Division of Culture and Education as a specialized and independent sector. The "program production spirit and DNA" that evolved from the experiences of working in poor production environment served as a force for developing professional and self identity. However, the culture and education PD's of the 70's were still tied down to the limited roles of simply providing technological and productional 'professionalism' within the hegemonic structure of the strong state. As with the members of any other social domain at the time, PD's had restricted roles to play and putting in effort and competing to create better programs was the only 'freedom' that was allowed. This study argues that under such condition, KBS PD's implemented two strategies to construct their own professional identities: one was to distinguish themselves from official broadcasters, and the other was to distinguish themselves from commercial broadcasters. Unfortunately, ethical practice as a professional became nothing more than an issue of personal morality and broadcasting's public responsibility was lost under the shadows of commercial broadcasting.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.106-116
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• 2001

A serious of studies on the fishing gear and system of the East Sea trawl fishery was carried out to improve the fishing efficiency and the working conditions. As the first step of these studies, the fishing gear and system of the traditional East Sea trawl were checked in order to solve the some problems, such as the poor sheering efficiency of net mouth, the inconvenient fishing system of the side trawl and etc. And then the fishing system was reorganized from the side trawl into the stern trawl by setting up the net drum system on the stern deck, and introduction of two types of new designed nets, one for mainly the midwater trawl and the other for the bottom trawl. The results of the field experiment on the modified system and nets can be summarized as follows : 1. the modified system was well worked and could save the man-labour by about 80%. 2. The sheering efficiency of the improved net, A type was improved to 20 m height and 30 m width in the net mouth, and that of B type net, to 10 m height and 33 m width, compared with 1.5 m height and 15 m width in the traditional net. 3. Catch efficiency of pink shrimp in A or B type net was better about 3 or 5 times than that of traditional net, and in B net, for herring and other bottom fishes is better about 2 times than that of the traditional net.