• KIPS Transactions on Software and Data Engineering
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• v.6 no.9
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• pp.457-464
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• 2017

Indoor air quality analysis is conducted to understand abnormal atmospheric phenomena and the external factor affecting indoor air quality. By recording indoor air quality measurements periodically, we are able to observe patterns in air quality. However, it difficult to predict the number of potential parameters, set parameters for a given observation and find the coefficients. Moreover, the results are time-dependent. Thus to address these issues, we introduce a microchip capable of periodically recording indoor air quality and a model that estimates atmospheric changes based on time series data.

• Proceedings of the KSRS Conference
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• v.1
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• pp.282-285
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• 2006

This paper analyzed the characteristics of the Lossy JPEG of the meteorological satellite image, and analyzed the quality of the Lossy JPEG compression, which is proper for the LRIT(Low Rate Information Transmission) to be serviced to the SDUS(Small-scale Data Utilization Station) system of the COMS(Communication, Oceans, Meteorological Satellite). Since COMS is to start running after 2008, we collected the data of the MTSAT-1R(Multi-functional Transport Satellite -1R) for analysis, and after forming the original image to be used to LRIT by each channel and time zone of the satellite image data, we set the different quality with the Lossy JPEG compression, and compressed the original data. For the characteristic analysis of the Lossy JPEG, we measured PSNR(Peak Signal to Noise Rate), compression rate and the time spent in compression following each quality of Lossy JPEG compression. As a result of the analysis of the satellite image data of the MTSAT-1R, the ideal quality of the Lossy JPEG compression was found to be 90% in the VIS Channel, 85% in the IR1 Channel, 80% in the IR2 Channel, 90% in the IR3 Channel and 90% in the IR4 Channel.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.69-86
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• 2020

Purpose: This study aims to determine the optimal conditions for the spot welding process that mechanically connects the case of a cylindrical secondary battery and the negative tab. Methods: We use 33 factorial design to derive the optimal conditions for the spot welding process. The pulling strength, the cross-sectional area of nugget, and the shock test life are selected as response variables, which can represent the resistance welding quality. The input variables are selected as the welding time, welding voltage, and pressure, which are the controllable factors in the spot welding process. Results: The main effects of welding time and welding voltage and the interaction effect of welding time and welding voltage are significant. Conclusion: The optimal conditions for the spot welding process to mechanically join the negative electrode tab of the cylindrical secondary battery and the battery case are developed. The result shows that the pulling strength is increased by 44% compared to before improvement under optimal conditions.

• Ocean and Polar Research
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• v.21 no.2
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• pp.117-126
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• 1999

To meet increasing needs for environmentally sustainable management of coastal area, there has been compelling pressure to establish a cost-effective and long-term coastal water quality (CWQ) monitoring system. A remote CWQ monitoring system, STAMP, has been developed and is in operation along the route between Kyema harbor and Anma Island in the southwestern coastal area of Korea. STAMP uses a PCS phone as a telemetry unit to transmit acquired data for monitoring general water quality parameters, and a routinely operating coastal passenger ship or car ferry. STAMP has various merits of low-cost operations; long-term monitoring with secure instrumentation; and stable real-time telemetry of acquired data with-out the loss and noise. It is expected that the system will serve as a very useful tool in the CWQ managing programs of Korea taking the advantage of many coastal passenger ships in various routes including the ships departing from the coastal industrial cities. The acquired data compiled on suspended surface sediment concentrations (SSSC) will be also valuably helpful in understanding the sediment budget across the routes of the vessel.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.230-235
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• 2008

This paper addresses issues associated with the real-time implementation of a wideband speech codec such as ITU-T G. 729. 1 on an ARM processor in order to provide an improved voice quality of a VoWiFi service. The real-time implementation features in optimizing the C-source code of G.729. 1 and replacing several parts of the codec algorithm with faster ones. The performance of the implementation is measured by the CPU time spent for G.729.1 on the ARM926EJ processor that is used for a VoWiFi phone. It is shown from the experiments that the G.729.1 codec works in real-time with better voice quality than G 729 codec that is conventionally used for VoIP or VoWiFi phones.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.252-252
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• 2000

The Resistance Spot Welding (RSW) has been considered as an inherently safe and reliable method far joining metals, and has been widely employed, especially in automobile body assembly shops, as a manufacturing process. In recent years, the requirement for more sophisticated quality control procedures has considerably grown in the mass production industries. The object of the application of servo control to spot welding gun is the improvement of quality control in the spot welding, one of conventional industrial areas. The important factors affecting welding qualities (shear strength, nuggest size, indentation depth) are welding current, welding time, and gun press force. Welding current and welding time are controlled by welding timer. But, the conventional welding guns using compressed air are out of control in changing gun press forces in welding process. In this paper, a servo gun welding system having a AC servo motor and a PC control system is presented. The main object of this paper is to estimate the influence of gun press force changes in the welding process (press time -> welding time -> hold time) to welding qualities, and to evaluate welding qualities in real time, by recognizing the patterns of gun press forces changed in the welding process and comparing with the standard patterns.

• Journal of the Korean Society of Food Culture
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• v.24 no.4
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• pp.426-432
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• 2009

The quality of baked Yackwa with rice bran oil varied with dipping temperature (80 and 25$^{\circ}C$) and dipping time (5, 10, and 15 minutes at 80$^{\circ}C$, and 60, 90, and 120 minutes at 25$^{\circ}C$). The moisture content and hardness of baked Yackwa increased and decreased, respectively, with dipping time. The expansion ratio increased with time when baked Yackwa was dipped at 80$^{\circ}C$, but decreased with time when dipped at 25$^{\circ}C$. Flavor and color were optimal for product dipped at 80$^{\circ}C$ for 15 minutes followed those dipped at 25$^{\circ}C$ for 120 minutes; the dipping conditions produced no significant difference in the degree of expension, aroma, texture, and overall quality. Baked Yackwa showed better results than fried Yackwa in sensory evaluation.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.121-129
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• 2008

Domestic exoteric construction market by opening of world construction market with recent FTA of rapidly change. On these time, need quality increase of construction to possess government official and international competitiveness of customer satisfaction by offering consumer building of good quality. Therefore, must establish direction to inspects and must advance forward formation government official's present actual conditions for building company's QI. This study is as following if summarize studying result of formation government official to improve quality in construction spot. First, formation's CEO will for QI need side improvement the formation government official enemy by important thing. Second, at checking activity and systematic action that participate of responsible persons cooperation enterprise space-time by complete charge department organization should be achieved. Third, complete charge department for quality control operation large size construction firm substantially formation Organizational well operate, but heavy hydrogen building company was construed by greatly unprepared misgovernment. AHP analysis result complete charge department is serious necessity, and the CEO under direct control organizational structure was construed by thing which can bring excellent effect in operation management side of quality business side and formation. Therefore, heavy hydrogen building company should does to occupy competitive power high position with tissue at active quality complete charge deputy.

• Water Engineering Research
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• v.3 no.2
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• pp.143-153
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• 2002

As the natural flows in rivers dramatically decrease during drought season in Korea, a deterioration of river water quality is accelerated. Thus, consideration of downstream water quality responding to changes in reservoir release is essential for an integrated watershed management with regards to water quantity and quality. In this study, water quality models based on artificial neural networks (ANNs) method were developed using historical downstream water quality (rm $\NH_3$-N) data obtained from a water treatment plant in Geum river and reservoir release data from Daechung dam. A nonlinear multiple regression model was developed and compared with the ANN models. In the models, the rm NH$_3$-N concentration for next time step is dependent on dam outflow, river water quality data such as pH, alkalinity, temperature, and rm $\NH_3$-N of previous time step. The model parameters were estimated using monthly data from Jan. 1993 to Dec. 1998, then another set of monthly data between Jan. 1999 and Dec. 2000 were used for verification. The predictive performance of the models was evaluated by comparing the statistical characteristics of predicted data with those of observed data. According to the results, the ANN models showed a better performance than the regression model in the applied cases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.314-321
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• 2011

There have been considerable standardization works to measure subjective video quality. However, these standardization methods are based on the situation where they have original or reference video sequences, and measure the video quality by looking the sequence during short time duration, e.g. 10 seconds. Since people's TV watching time durations in IPTV services are very long (e.g. more than 30 minutes), the quality measurements by the standards are not practical. In this paper, we analyze the effect of video quality rating period to MOS (Mean Opinion Score), and suggest a proper rating duration of subjective video quality for IPTV services.