• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.764-769
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• 2007

This paper proposes a new model to· evaluate the effectiveness of websites using balanced scorecard (BSC) and weighted formula based methods.fisrt, we Use BSC method to find out the cause-and-effect relationships between the measure and website activities, and our proposed model evaluates website performance from six perspectives: business value, operational excellence, customer value, website interface, management, maintenance, and learning and innovation. Next, we usedformula-based approach to identify what makes website performance low by developing the evaluation formula through investigating website users; finally, case studies of two famous websites are given to show how our method can be used Our evaluation model can not only evaluate website performance but also suggest how to improve performance.

• IE interfaces
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• v.16 no.spc
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• pp.105-110
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• 2003

This paper deals with a performance evaluation model of transporters in refrigerate warehouse. This study focussed on determining refrigerate warehouse design to minimize the expected travel time to improve the transporter performance and to minimize the operating costs. This study proposes the important detail aspects of refrigerate warehouse design, operational parameters and congestions. For solving this problem, we have shown a mathematical model to compute the initial value of the system performance and also a simulation model using AutoMod. A systematic approach proposed in this study for an optimal planning of order-picking warehouse is known as an effective method for the planning of order-picking warehouse and a performance evaluation problem of refrigerate warehouse operation.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.226-238
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• 2011

RAMS (Reliability, Availability, Maintainability, Safety) study has received far less rigorous analysis in the system performance and integration level, and RCM (Reliability Centered Maintenance) research has been studying to improve the maintenance efficiency in the operational steps based on collected data of real operational cases. This paper analyzes the basic concepts based on KS X ISO/IEC 15288 system life-cycle process in the whole system for the light rail transit construction, and the research suggests an approach to the management process of the applicable main tasks. The paper "Management Process Study to RAMS Application of Light Rail Transit System" introduces Airport Rail cases and guidelines by using RAMS which is the major role in the system engineering technical process of ISO/IEC 15288 (International Organization for Standardization/International Electrotechnical Commission 15288) to apply RAMS in domestic light rail transit efficiently, the aim of this study is to broaden of understanding RAMS.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.11
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• pp.47-55
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• 1997

In general, processing flow of the conventional floating-point multiplication consists of either multiplication, addition, normalization, and rounding stage of the conventional floating-point multiplier requries a high speed adder for increment, increasing the overall execution time and occuping a large amount of chip area. A floating-point multiplier performing addition and IEEE rounding in parallel is designed by using the carry select addder used in the addition stage and optimizing the operational flow based on the charcteristics of floating point multiplication operation. A hardware model for the floating point multiplier is proposed and its operational model is algebraically analyzed in this paper. The proposed floating point multiplier does not require and additional execution time nor any high spped adder for rounding operation. Thus, performance improvement and cost-effective design can be achieved by this suggested approach.

• Korean System Dynamics Review
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• v.12 no.1
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• pp.89-114
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• 2011

With steady increase in the demand for door-to-door delivery services, courier service providers are facing a constant pressure to reduce delivery price in order to secure quantity order and to improve the efficiency and reliability for customer service. The objective of this research is to explain the structure of the door-to-door delivery including door-to-door delivery service demand, sorting capacity in the hub-terminal, and the system performance measures such as service reliability networks using causal loop diagram(CLD). Based on causal relation, this research describes a comprehensive approach to examine how capacity reliability contributes to the renewal of the firm's competences through its reciprocal relationship with travel time reliability and connectivity reliability. Also, this research suggests the policy alternatives to improve effectiveness and efficiency of door-to-door delivery network in response to increase customer satisfaction and profit maximization of the courier service providers: operational, tactical, and strategic levels.

• Journal of Hydrogen and New Energy
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• v.35 no.4
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• pp.437-450
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• 2024

Sustainable shipping depends on eco-friendly energy solutions. This paper reviews methods for predicting marine fuel cell performance, including empirical approaches, physical modeling, data-driven techniques, and hybrid methods. Accurate prediction models tailored to the marine environment's unique conditions are crucial for operational efficiency. By evaluating the strengths and weaknesses of each method, this study provides a comprehensive analysis of effective strategies for forecasting polymer electrolyte membrane fuel cell and solid oxide fuel cell performance in marine applications. These insights contribute to the advancement of eco-friendly shipping technologies and enhance fuel cell performance in challenging marine environments.

• Safety and Health at Work
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• v.12 no.4
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• pp.462-470
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• 2021

Background: Fatigue is pervasive, under-reported, and potentially deadly where flight operations are concerned. The aviation industry appears to lack a standardized, practical, and easily replicable protocol for fatigue risk assessment which can be consistently applied across operators. Aim: Our paper sought to present a framework, supported by real-world data with subjective and objective parameters, to monitor aircrew fatigue and performance, and to determine the safe crew configuration for commercial airline operations. Methods: Our protocol identified risk factors for fatigue-induced performance degradation as triggers for fatigue risk and performance assessment. Using both subjective and objective measurements of sleep, fatigue, and performance in the form of instruments such as the Karolinska Sleepiness Scale, Samn-Perelli Crew Status Check, Psychomotor Vigilance Task, sleep logs, and a wearable actigraph for sleep log correlation and sleep duration and quality charting, a workflow flagging fatigue-prone flight operations for risk mitigation was developed and trialed. Results: In an operational study aimed at occupational assessment of fatigue and performance in airline pilots on a three-men crew versus a four-men crew for a long-haul flight, we affirmed the technical feasibility of our proposed framework and approach, the validity of the battery of assessment instruments, and the meaningful interpretation of fatigue and work performance indicators to enable the formulation of safe work recommendations. Conclusion: A standardized occupational assessment protocol like ours is useful to achieve consistency and objectivity in the occupational assessment of fatigue and work performance.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.1
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• pp.23-35
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• 2023

Korea Augmentation Satellite System (KASS) is a satellite-based augmentation system (SBAS) that provides approach procedure with vertical guidance-I (APV-I) level corrections and integrity information to Korea territory. KASS is used to monitor navigation performance in real-time, and this paper introduces the design, implementation, and verification process of mission monitoring (MIMO) in KASS. MIMO was developed in compliance with the Minimum Operational Performance Standards of the Radio Technical Commission for Aeronautics for Global Positioning System (GPS)/SBAS airborne equipment. In this study, the MIMO system was verified by comparing and analyzing the outputs of reference tools. Additionally, the definition and derivation method of accuracy, integrity, continuity, and availability subject to MIMO were examined. The internal and external interfaces and functions were then designed and implemented. The GPS data pre-processing was minimized during the implementation to evaluate the navigation performance experienced by general users. Subsequently, tests and verification methods were used to compare the obtained results based on reference tools. The test was performed using the KASS dataset, which included GPS and SBAS observations. The decoding performance of the developed MIMO was identical to that of the reference tools. Additionally, the navigation performance was verified by confirming the similarity in trends. As MIMO is a component of KASS used for real-time monitoring of the navigation performance of SBAS, the KASS operator can identify whether an abnormality exists in the navigation performance in real-time. Moreover, the preliminary identification of the abnormal point during the post-processing of data can improve operational efficiency.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.3
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• pp.70-81
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• 2019

The effects of weather on aircraft operations are predominant. In particular, severe weather, such as fog, strong winds, rainfall and snow, can cause delays, diversion or cancellation of operations. Of these, fog is considered the main reason for restricting aircraft operations. Meanwhile, Precision instrument approach using instrument landing system(ILS) has allowed aircraft to land safely even in situations where visibility is limited. However, the precision instrument approach require not only the performance of the aircraft but also the enhancement of the runway. In November 2018, Gimpo international Airport raised the category of the runway 14R from CAT-IIIa to CAT-IIIb to improve aviation safety and operational efficiency. Based on this, the research presented a methodology for estimating benefits according to the category upgrade of the precision approach runway, and estimated the benefits to Gimpo International Airport based on the methodology presented.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.361-369
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• 2018

This paper proposes a design of asymmetric time division multiple access method for tactical radio communication. Typical tactical radio communication has a limited execution of transmission, because uplink message requires more extended response time than downlink message. In order to solve this problem, this paper analyzes operational environment of Korean tactical radio communication and proposes an asymmetric TDMA based on it for performance of tactical communication. The simulation model is used to investigate constraints of real experiments for proving effectiveness of the proposed approach. Simulations results show that the proposed scheme outperforms the conventional scheme in terms of throughput, response time, and delay.