• 시스템엔지니어링학술지
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• 제17권2호
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• pp.23-36
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• 2021

Recently, the rapid development of drones is increasing as a variety of threats to important facilities of the country. In order to build an anti-drone system that responds to drones with high technical characteristics, standardization is required in terms of operation, system, and technology. By applying the defense architecture framework, it contributes to the establishment of the optimal system by proposing a standardization plan for the operational and system perspectives of the anti-drone system by creating outputs equivalent to the stage of prior research on weapons systems. It is a prerequisite for building a drone system the operational concept of the anti-drone system, the definition of the drone threat, the function of each component, the interface, the definition of data flow, the system performance and effect scale, etc. Management, security officers, and equipment manufacturers of important national and public facilities on site expect that it will be used as an objective standard at the government level for the component technology of the equipment to respond to the drone threat and the performance required in the environment.

• 한국습지학회지
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• 제19권2호
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• pp.211-215
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• 2017

하수처리장 운영 시장 규모는 전세계적으로 증가하고 있는 추세이다. 이에 하수처리장 관리 대행 제도는 국내 하수처리장의 효율적인 운영을 위해 도입되었지만 지속적으로 개선의 필요성이 제기되고 있다. 본 연구에서는 하수처리장 관리 제도의 활성화를 위해 현행 하수처리장 운영비용 현황 조사 및 개선 방안을 연구하였다. 하수처리장 용량이 클수록 하수처리단가가 감소하는 하는 경향을 보였다. 전체 하수처리장 운영 단가는 공기업이 가장 저렴하였지만, 유사 하수 처리장(유사 용량, 유사 공법, 유사 운영 기간)의 운영비용을 비교하였을 경우 민간 기업이 가장 저렴한 것으로 나타났다. 하수처리장 관리 및 운영 관계자들과의 면담 조사 결과 관리대행업자 선정 및 운영 비용 산정 방법 개선이 필요하다는 의견이 제시되었다. 본 연구는 하수처리장 관리 대행 활성화를 위한 방안 제시를 위한 기초 자료로 활용 될 수 있을 것으로 판단한다.

• 한국산림과학회지
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• 제104권2호
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• pp.230-238
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• 2015

현재 우리나라의 주요 임업기계에 의한 임목수확작업시스템에서 벌목 및 조재, 집재, 소운재, 파쇄 등의 목재생산 및 파쇄작업에 대한 작업비용을 분석하여, 산림바이오매스 이용을 위한 효율적인 임목수확작업시스템을 구축하기 위한 기초자료를 제공하고자 수행하였다. 임목수확작업시스템의 작업비용을 분석한 결과, 체인톱에 의한 벌목 및 조재와 타워야더에 의한 집재, 임내작업차에 의한 소운재, 트럭에 의한 운재작업으로 이루어진 임목수확작업시스템 D가 63,482원/$m^3$으로 가장 적은 비용이 소요되는 것으로 나타났다. 또한, 산림바이오매스 이용을 위한 작업시스템의 작업비용을 분석한 결과, 소형 목재파쇄기에 의한 현장파쇄, 임내작업차에 의한 칩 소운반, 트럭에 의한 칩 운반작업의 작업시스템 E가 90,770원/ton으로 가장 적은 비용이 산출되었다. 따라서, 이들의 결과가 임목수확작업 및 산림바이오매스 이용을 위한 효율적인 작업시스템이라고 판단된다.

• Ocean and Polar Research
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• 제43권3호
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• pp.179-192
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• 2021

In this study, an integrated wave model from global to coastal scales was developed to improve the operational wave prediction performance of the Korean Meteorological Administration (KMA). In this system, the wave model was upgraded to the WaveWatch III version 6.07 with the improved parameterization of the source term. Considering the increased resolution of the wind input field and the introduction of the high-performance KMA 5^th Supercomputer, the spatial resolution of global and regional wave models has been doubled compared to the operational model. The physical processes and coefficients of the wave model were optimized for the current KMA global atmospheric forecasting system, the Korean Integrated Model (KIM), which is being operated since April 2020. Based on the sensitivity experiment results, the wind-wave growth parameter (β_max) for the global wave model was determined to be 1.33 with the lowest root mean square errors (RMSE). The value of β_max showed the lowest error when applied to regional/coastal wave models for the period of the typhoon season when strong winds occur. Applying the new system to the case of August 2020, the RMSE for the 48-hour significant wave height prediction was reduced by 13.4 to 17.7% compared to the existing KMA operating model. The new integrated wave prediction system plans to replace the KMA operating model after long-term verification.

• 한국항공우주학회지
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• 제35권9호
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• pp.836-842
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• 2007

본 논문에서는 자동으로 궤도를 결정하고, 신뢰성을 판정한 후 임무계획, 위성추적, 위성위치 표시에 사용하도록 갱신하며, 안테나 추적을 위해 필요한 여러 가지 형태의 궤도데이터 파일을 생성하는 ‘자동 궤도운용 시스템 (KGS automated Operational Orbit Processing System, KOOPS)'의 개발 내용 및 실제 운용 결과를 기술하였다. 개발된 본 시스템은 다양한 형태의 궤도추적 데이터를 처리할 수 있으며, 각 위성 시스템에 따라 필요한 다양한 전처리 및 후처리 프로세스들을 각 위성 별로 개별적으로 설정할 수 있기 때문에 여러 기의 서로 다른 임무를 가진 “다중, 복합” 위성 궤도운용 시스템으로 적용이 가능하다. 아리랑 1호 및 아리랑 2호의 추적 및 임무계획을 위한 비행역학 시스템으로써 적용되어 운용한 결과, 임무운용의 효율성 및 안정성을 크게 높이고, 인력 소요를 대폭 줄이는 효과를 얻을 수 있었다. 본 시스템의 개발 과정과 실제 적용을 통해 얻은 경험은 향후 보다 효율적이고 자동화된 “통합지향형 범용” 비행역학 시스템 개발에 직접 활용될 수 있을 것으로 사료된다.

• 한국초전도ㆍ저온공학회논문지
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• 제17권1호
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• pp.32-35
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• 2015

Many kinds of high temperature superconducting (HTS) devices are being developed due to its several advantages. In particular, the advantages of HTS devices are maximized under the DC condition. A line commutated converter (LCC) type high voltage direct current (HVDC) transmission system requires large capacity of DC reactors to protect the converters from faults. However, conventional DC reactor made of copper causes a lot of electrical losses. Thus, it is being attempted to apply the HTS DC reactor to an HVDC transmission system. The authors have developed a 8 mH class HTS DC reactor and a model-sized LCC type HVDC system. The HTS DC reactor was operated to analyze its operational characteristics in connection with the HVDC system. The voltage at both ends of the HTS DC reactor was measured to investigate the stability of the reactor. The voltages and currents at the AC and DC side of the system were measured to confirm the influence of the HTS DC reactor on the system. Two 5 mH copper DC reactors were connected to the HVDC system and investigated to compare the operational characteristics. In this paper, the operational characteristics of the HVDC system with the HTS DC reactor according to firing angle are described. The voltage and current characteristics of the system according to the types of DC reactors and harmonic characteristics are analyzed. Through the results, the applicability of an HTS DC reactor in an HVDC system is confirmed.

• 한국프랜차이즈경영연구
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• 제14권4호
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• pp.35-50
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• 2023

Purpose: This study aims to uncover the mechanism of how initial fees are determined in the restaurant franchise business. Since the initial fees can be considered as a price of utilizing business models and operational knowledge of a certain franchise brand, it is critical to understand the fee decision-making process based on the strategic pricing theories. Therefore, this study investigates the influence of operational value on the determination of initial franchise fees grounded on a value-based pricing strategy. The Operational value is specifically categorized into profitability, growth, and stability of the franchise system. Research design, data, and methodology: The data used were collected through franchise disclosure documents and brand equity index provided by Korea Management Association Consulting. Data from 44 franchise restaurants during 2018 to 2021 are included in the sample. The panel dataset was analyzed by using generalized least squares estimation with R-Studio. Results: Profitability and stability positively influence initial franchise fees. However, growth did not influence initial franchise fees. Conclusions: The results of the study demonstrate that the operational value plays a critical role in determining the franchise fees. Specifically, franchisees recognize how much revenue a franchise system generates for them (i.e., profitability) and how stable the entire system is for operating business (i.e., stability) when they make purchasing decisions for franchise. The findings extend the pricing literature by applying pricing theories in the franchise fee context. Also, the study contributes to franchising and restaurant management literature by providing knowledge of how franchise fees are determined.

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.452-464
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• 2015

This paper proposes a DC microgrid operational strategy and control method for improved service reliability. The objective is to supply power to as many non-critical loads as possible, while providing an uninterrupted power supply to critical loads. The DC bus signaling method, in which DC voltage is an information carrier, is employed to implement the operational strategy in a decentralized manner. During grid-connected operation, a grid-tied converter balances the power of the microgrid by controlling the DC voltage. All loads are connected to the microgrid, and operate normally. During islanded operation, distributed generators (DGs), a backup generator, or an energy storage system balances the power. However, some non-critical loads may be disconnected from the microgrid to ensure the uninterrupted power supply to critical loads. For enhanced service reliability, disconnected loads can be automatically reconnected if certain conditions are satisfied. Control rules are proposed for all devices, and detailed microgrid operational modes and transition conditions are then discussed. Additionally, methods to determine control parameter settings are proposed. PSCAD/EMTDC simulation results demonstrate the performance and effectiveness of the proposed operational strategy and control method.

• 한국군사과학기술학회지
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• 제11권1호
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• pp.5-14
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• 2008

In this paper, we propose operational concepts and technology requirements for guard and surveillance robots in military field. After surveying on current trend of guard robots, we present an operational scenario and technology requirements. To begin with, we discriminate the use of fixed type guard robots(fixed robots) and mobile guard and surveillance robots(mobile robots). Fixed robots are used for substituting daily guard by human soldier. In contrast, mobile robots are used for compensating shadow area where not to be covered by fixed type robots. To be specific, mobile robots adopt communication relays to extend operational range and sensor networks to collecting information. In addition, we present technology requirements composed of wireless communication system, platform, sensor nodes, unmanned driving technology, power supply system and IFF etc. In conclusion, in order to maximize co-operational functionality, fixed robots and mobile robots should be tightly related.

• Earthquakes and Structures
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• 제11권6호
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• pp.1043-1060
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• 2016

The engineering background of this article is an ancient wooden building with extremely high historic and cultural values in Tibet. A full understanding of the dynamic behaviour of this historic building under in-service environments is the basis to assess the condition of the structure, especially its responses to earthquake, environmental and operational loading. A dynamic monitoring system has been installed in the building for over one year and the large amounts of high quality data have been obtained. The paper aims at studying the dynamic behaviour of the wooden building in seismic and operational conditions using the field monitoring data. Specifically the effects of earthquake and crowd loading on the structure's dynamic response are investigated. The monitoring data are decomposed into principal components using the Singular Spectrum Analysis (SSA) technique. The relationship between the average acceleration amplitude and frequencies of the principle components and operational conditions has been discussed. One main contribution is to understand the health condition of complex ancient building based on large databases collected on the field.