• The Journal of the Acoustical Society of Korea
• /
• v.28 no.5
• /
• pp.477-482
• /
• 2009

The emotion recognition system in commercial environments such as call-center undergoes severe system performance degradation and instability due to the speech characteristic differences between the system training database and the input speech of unspecified customers. In order to alleviate these problems, this paper extends traditional method of emotion recognition of neutral/anger into two-step hierarchical structure by using emotional characteristic changes and differences of male and female. The experimental results indicate that the proposed method provides very stable and successful emotional classification performance about 25% over the traditional method of emotion recognition.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.47 no.1
• /
• pp.20-27
• /
• 2024

Determining the number of operators who set up the machines in a human-machine system is crucial for maximizing the benefits of automated production machines. A man-machine chart is an effective tool for identifying bottlenecks, improving process efficiency, and determining the optimal number of machines per operator. However, traditional man-machine charts are lacking in accounting for idle times, such as interruptions caused by other material handling equipment. We present an adjusted man-machine chart that determines the number of machines per operator, incorporating idleness as a penalty term. The adjusted man-machine chart efficiently deploys and schedules operators for the hole machining process to enhance productivity, where operators have various idle times, such as break times and waiting times by forklifts or trailers. Further, we conduct a simulation validation of traditional and proposed charts under various operational environments of operators' fixed and flexible break times. The simulation results indicate that the adjusted man-machine chart is better suited for real-world work environments and significantly improves productivity.

• Nuclear Engineering and Technology
• /
• v.56 no.2
• /
• pp.762-769
• /
• 2024

The TMSR-SF0 simulator is an integral effect thermal-hydraulic experimental system for the development of thorium molten salt reactor (TMSR) program in China. The simulator has two heat transport loops with liquid FLiNaK. In literature, the 95% level confidence uncertainties of the thermophysical properties of FLiNaK are recommended, and the uncertainties of density, heat capacity, thermal conductivity and viscosity are ±2%, ±10, ±10% and ±10% respectively. In order to investigate the effects of thermophysical properties uncertainties on the molten salt heat transport system, the uncertainty and sensitivity analysis of the heat transfer characteristics of the simulator system are carried out on a RELAP5 model. The uncertainties of thermophysical properties are incorporated in simulation model and the Monte Carlo sampling method is used to propagate the input uncertainties through the model. The simulation results indicate that the uncertainty propagated to core outlet temperature is about ±10 ℃ with a confidence level of 95% in a steady-state operation condition. The result should be noted in the design, operation and code validation of molten salt reactor. In addition, more experimental data is necessary for quantifying the uncertainty of thermophysical properties of molten salts.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.10
• /
• pp.2840-2856
• /
• 2024

Massive multiple-input multiple-output (MIMO) has emerged as a pivotal technology to address the escalating communication demands of Internet of Things (IoT). To meet the data transmission needs in IoT systems, we propose an antenna selection method of massive MIMO systems and joint power allocation strategy considering IoT user devices grounded in quantum energy valley optimization (QEVO) in this paper. The derivation of a maximum energy efficiency equation has been established to optimize system resources and provide high quality of service meeting the IoT user devices requirements. To tackle the nonlinear, multiconstrained hybrid optimization challenge proposed for massive MIMO resource allocation in IoT systems, we introduce a quantum energy valley optimization algorithm. This algorithm harnesses the strengths of quantum computation and energy valley optimization (EVO) mechanisms. Simulations indicate that our proposed method can efficiently meet real-time user transmission requirements while markedly enhancing system energy efficiency. When compared with existing power allocation strategies and optimization algorithms applied in massive MIMO communication systems, our approach demonstrates superior performance. The proposed method demonstrates the highest performance across various simulation scenarios when applied to both allocation strategies and system energy efficiency. Our proposed method with highest performance can be properly used on massive IoT devices.

• Korean Journal of Microbiology
• /
• v.42 no.1
• /
• pp.26-33
• /
• 2006

To understand the efficient process of biological nitrogen removal (BNR) system, the structure of bacterial communities in nitrification reactors was analyzed using PCR and terminal restriction fragment length poly morphism (I-RFLP) methods. In this study, we used an advanced treatment system with plotting media, Nutrient Removal Laboratory system, or the rumination type sequencing batch reactor (SBR) system. The terminal restriction fragments of ammonia-oxidizing bacteria (AOB) and other $\beta-proteobacteria$ were observed in all of three BNR systems. The nucleotide sequence analysis of terminal restriction fragments showed that Nitrosomonas and Nitrosolobus were major populations of AOB in SBR system, whereas uncultured $\beta-proteobacteria$ and Cardococcus australiensis were the predominant groups in other two BNR systems. Also the SBR system may be more efficient to enrich AOB. These results indicate that the different structure of bacterial community may be developed depending on the wastewater treatment systems, although the same influent is used.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.7
• /
• pp.947-952
• /
• 2010

Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions prescribed in ISO and SAE standards. The impulse pressure test machine needs to have a high pressure, a precise control system and a long life. It should satisfy the requirements for fabrication of the impulse tester to generate ultra high pressure in the hydraulic system. In the impulse tester, a servo-valve control system is adopted; although the control application is convenient, it is expensive owing to the cost of developing the system. The type of the control system determines the pressure wave, which affects the components that are tested. In this study, the manufacturing process and the intensifier system design related to the flow, pressure, and the increasing rate of pressure are investigated. The results indicate the ultra high pressure waves in the system.

• Journal of the Korea Society of Computer and Information
• /
• v.4 no.4
• /
• pp.209-217
• /
• 1999

This study investigated a special class or Electronic Data Interchange(EDI) system. While it has been predicted that the use of EDI will have a significant impact on the competitive advantage of organization. very little is known about the successful construction of such system. A few studies done in this area have relied on anecdotal data on data based on a small number of case studies. The major objectives of the research are to identify the factors that facilitate the adoption and successful construction of an EDI system, and to evaluate the impact of the EDI system on competitive advantage of the organization. Based on the EDI literature. organizational performance is modeled to be affected by three independent variables: EDI system. communication. trust. The level of EDI system was used as control variable. The data used to test the model were collected in a mail survey from department store in Korea. The results indicate that organizational performance is affected by EDI system, communication. The paper concludes with a discussion of future directions for research in the area of test EDI models.

• Journal of Korean Academy of Nursing Administration
• /
• v.21 no.5
• /
• pp.519-529
• /
• 2015

Purpose: This study was performed to identify perceptions on fixed night shift system and turnover intention of general hospital nurses and to explore a desirable application plan for a fixed night shift system. Methods: This study was a cross-sectional survey. Participants were 300 nurses working at one general hospital in GyeongGi-Do, Korea. Data were collected from November 3 to 7, 2014, with a structured questionnaires and analyzed using SPSS/PC ver 20.0 programs. Results: Of the participants 73.5% had thought about turnover because of night shifts and the preconditions for desirable fixed night shift system were a payment plan differentiated according to work conditions and an adequate number of nursing staff. Economic and administrative supports like 'raising extra-pay for night shift' and 'increasing the number of paid holidays' were very important for a desirable fixed night shift system. Conclusion: The results indicate that the most important factor for a desirable fixed night shift system to decrease nurses' turnover intention is economic and administrative support according to the needs of the nurses. So nursing managers need to find a desirable fixed night shift system considering nurses' demographic characteristics and organizational characteristics.

• Resources Recycling
• /
• v.25 no.1
• /
• pp.68-75
• /
• 2016

Realization of zero waste society, which includes reduction, recycling and reuse of waste, has been a huge issue in Korea recently, and many experts are proposing various improvement plans in the establishment of political system. In particular, the current EPR system is partially agreed on its external achievement, but many problems are arising from the enforcement of the system. Therefore, flexible revisions and modifications on recycling policy are necessary. In order to understand the insufficiency and problem of the expansion of items in current EPR system, this study examined the actual generation and basic unit in small, medium and large-scale apartment complexes in B City and predicted the items that do not appear in the statistics to compare and analyze the problems in current recycling based on their result value; a survey was conducted on 137 experts and students of relevant major that live in B City on the items of EPR system and their perceptions to indicate the error in the necessity of items in EPR system that are generally underperceived by people and the error of current recycling system, and solution plans were sought to establish smooth future system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.8
• /
• pp.325-330
• /
• 2016

This study was conducted to develop a heating system for a fuel cell-driven electric vehicle. The system consists of a compressor, an expansion device and three heat exchangers. A conventional air source heat exchanger is used as primary heat exchanger of the system, and an additional water source heat exchanger is used as a pre-heater to supply heat to the upstream air of the primary heat exchanger. On the other hand, the third heat exchanger consists of a water-to-refrigerant heat exchanger. The heat source of the pre-heater and the water-refrigerant heat exchanger is the waste heat from the fuel cell's stack. In the experiment, the indoor and the outdoor air temperature were fixed, and the compressor speed, EEV opening and waste heat temperature were varied. The results indicate that the $COP_h$ of the proposed system is 3.01 when the system is operating at a 1,200 rpm compressor speed, 50% EEV opening, and $50^{\circ}C$ waste heat source temperature in air pre-heater operation. However, when the system uses a water-refrigerant heat exchanger, the $COP_h$ increases to up to 9.42 at the same compressor speed and waste heat source temperature with 75% EEV openings.