• 방사성폐기물학회지
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• 제16권2호
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• pp.211-221
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• 2018

중성자 확산방정식에 대해 개발된 노달 확산이론을 단순 우성 중성자 수송방정식에 적용할 수 있는 노달 수송이론을 제시한다. 노달이론으로 다항식전개 노달법과 해석함수전개 노달법을 채택하였고 단순 우성 수송방정식은 수송방정식에 대한 합리적 근사이며 기존의 노달해법이 방향 차분된 단순 우성 수송방정식에 정확히 적용될 수 있음을 수치적으로 확인하였다. 본 연구에서는 방법론 개발이 목적이므로 노드 당 최소한의 미지수를 정의하여 사용했지만 미지수를 추가함으로써 정확도를 증가시킬 수 있음은 기존의 노달 확산이론의 경우와 같다. 즉 중성자 수송방정식에 대해 노달이론을 적용하여 소격격자에 대해 계산 정확성이 확보되고 이는 결국 계산 효율성 증대로 나타난다.

• The Journal of Asian Finance, Economics and Business
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• 제10권2호
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• pp.235-245
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• 2023

This study examines the low performance of state civil servants related (ASN) to the management of public transportation at the Directorate of Road Transport (DRT), Ministry of Transportation, Indonesia. This study surveyed 103 ASNs, using a quantitative approach using the Amos SEM software. The results showed that Knowledge Sharing (KS) and Work Engagement (WE) directly influenced Innovative Work Behavior (IWB) as well as Job Performance (JP). Meanwhile, IWB had a significant, direct effect on JP and acts as a full mediator in the effect of KS and WE on JP. The descriptive data obtained also showed that respondents' statements based on gender have differences related to the IWB variable, where on average, women were better than men. However, for other variables (JP, KS, and WE), the data showed that, on average, the statements of male respondents were better than women. This study recommends that the DRT pay attention to IWB as a key factor mediating KS and WE towards increasing JP by maintaining the best indicators and improving the weakest indicators. Furthermore, this study recommends that future research refine these results by adding the variables of gender and educational level of the respondents.

• 한국인쇄학회지
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• 제12권1호
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• pp.1.1-11
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• 1994

The photosensitive properties and carrier transport in the organic photoconductor with the carrier transport layers(CTL) of polymer matrix doped with two carrier transport materials above carrier generation layer(CGL) containing oxotitanium phthalocyanine (TiOPc) were investigated. The CGL of TiOPc dispersed in poly(vinylbutyral) was formed as thickness of 0.1${\mu}{\textrm}{m}$and the carrier transport layer was prepared by coating polycarbonate and polyester doped with oxadiazoly(OXD), polyvinylcarbazole (PVK), trinitro fluorenone(TNF) as thickness of 10~15${\mu}{\textrm}{m}$, respectively. We have measured half decay exposure,sensitivity and xerographic gain from the photo-induced discharge curve(PIDC). In this work, it was found that the characteristics of carrier transport were mainly caused by the ionization potential difference of constitutive materials in molecularly doped polymer.

• Coupled systems mechanics
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• 제9권1호
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• pp.63-75
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• 2020

Transport is the central ingredient of all numerical schemes for hyperbolic partial differential equations and in particular for hydrodynamics. Transport has thus been extensively studied in many of its features and for numerous specific applications. In more than one dimension, it is most commonly plagued by a major artifact: mesh imprinting. Though mesh imprinting is generally inevitable, its anisotropy can be modulated and is thus amenable to significant reduction. In the present work we introduce a new definition of stencils by taking into account second nearest neighbors (across cell corners) and call the resulting strategy "co-mesh approach". The modified equation is used to study numerical dissipation and tune enlarged stencils in order to minimize transport anisotropy.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.55-56
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• 1996

Heterophase polymer system has been attractive for a potential applicability to gas separation membrane material. It has been known that there is a trade-off between gas permeability and its selectivity in common polymers. Therefore, the heterophase polymer can be an alternative for a gas separation membrane material because its transport properties can be readily controlled by blending of two different polymers. The transport properties of immiscible polymer blends strongly depend upon the intrinsic transport properties of corresponding polymers. Another important factor to determine the transport properties is their morphology: volume fraction, size and shape of dispersed phase. Although the effect of the volume fraction of the dispersed phase on the transport properties has been widely investigated, the size and shape effects have been paid attention very much. In an immiscible polymer blend of two polymers, its morphology is primarily controlled by its volume fraction of dispersed phase. Therefore, the effect of the size of the dispersed phase can be hardly seen. Therefore, a block copolymer has been commonly employed to control their morphology when each block is miscible with one or the other phase. In this work, gas transport properties will be measured by varying the morphology of the heterophase polymer membrane. The transport properties will be interpreted in terms of their morphology. The effect of the volume fraction of the PI phase and, in particular, its size effect will be investigated experimentally and theoretically.

• 한국통신학회논문지
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• 제30권3B호
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• pp.85-94
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• 2005

본 논문은 적응형 오류제어 기법을 바탕으로 신뢰성 있는 UDP 기반의 미디어 고속 전송을 제안한다. 제안된 적응형 전송기법은 대역폭의 변화에 효과적으로 대처하기 위해서 네트워크 모니터링을 기반으로 잉여 데이터의 양을 제어한다. 수신측 피드백은 패킷 손실의 유형, 전송률 등의 수신 상황을 송신측이 인지하도록 하여 앞으로 발생될 네트워크 상황을 예측하고 이를 바탕으로 전송률과 적응형 FEC 코드 조합을 적응적으로 제어함으로써 신뢰성 있는 전송을 가능하게 한다. 제안된 시스템의 성능을 측정하기 위한 고속 네트워크에서의 전송 실험은 수백 Mbps의 전송 속도를 보이며 향상된 신뢰성을 보여준다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.3711-3730
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• 2014

Cognitive radio networks (CRNs) have emerged as a promising solution to enhance spectrum utilization by using unused or less used spectrum in radio environments. The basic idea of CRNs is to allow secondary users (SUs) access to licensed spectrum, under the condition that the interference perceived by the primary users (PUs) is minimal. In CRNs, the channel availability is uncertainty due to the existence of PUs, resulting in intermittent communication. Transmission control protocol (TCP) performance may significantly degrade in such conditions. To address the challenges, some transport protocols have been proposed for reliable transmission in CRNs. In this paper we survey the state-of-the-art transport protocols for CRNs. We firstly highlight the unique aspects of CRNs, and describe the challenges of transport protocols in terms of PU behavior, spectrum sensing, spectrum changing and TCP mechanism itself over CRNs. Then, we provide a summary and comparison of existing transport protocols for CRNs. Finally, we discuss several open issues and research challenges. To the best of our knowledge, our work is the first survey on transport protocols for CRNs.

• 유통과학연구
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• 제20권5호
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• pp.23-33
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• 2022

Purpose: The purpose of this article is to study the theory of railway transport in Azerbaijan. And also to determine the economic importance of this mode of transport and analyze its relationship with the country's GDP. Research design, data and methodology: This paper studies the theory of railway transport with a focus on the case of Azerbaijan. The economic value of this type of transport is determined, and its relationship with countries' GDP was analyzed. A qualitative model of multiple regressions was developed to characterize the dependence of the GDP of Azerbaijan on the performance of the railway industry. The feasibility of the Gauss-Markov hypotheses was analyzed. Finally, an economic interpretation of the results from the developed model is provided. Results: The results show that the main factors of this dependence are the length of roads and the average monthly salary of employees of the railway industry in Azerbaijan. Conclusions: Therefore, it can be concluded that rail transport contributes to the country's economy. The commencement of active work on the new railway Baku-Tbilisi-Kars railway will increase contribution to the economy of Azerbaijan. The development of railway transportation is important for the country's economy, as it will contribute to the development of other sectors in Azerbaijan.

• 한국항공운항학회지
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• 제32권1호
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• pp.28-38
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• 2024

Due to globalization, the air transport industry plays a key role in the global economy. In particular, the air transport industry is highly dependent on human resources, and the capabilities of the cabin crews in managing safety and providing service in a cabin depend on the service quality and the success of the company's human resource management. Therefore, systematic support and interest in competitive key personnel are believed as very important factors. Airlines need to improve the work engagement of airline cabin crew through organizational supportive efforts. Thus this paper surveyed 309 cabin crews who worked at low cost carrier and conducted an empirical analysis based on survey results. The study validates hypotheses pertaining the relationship between organizational identification and job commitment of cabin crew according to the airline's perception of organizational support. The comprehensive analysis reveals that perceived organization support has a significantly positive impact on cabin crews' work engagement.

• 한국ITS학회 논문지
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• 제7권1호
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• pp.127-136
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• 2008

최근 도로의 유지관리 개념의 중요성이 대두되면서 도로 자체의 유지보수 확장이나 도로선형 개량 등 도로상에서 각종 공사의 빈도가 증가하고 있다. 특히 고속으로 주행하는 고속도로 상에서 도로점용공사로 인하여 차로가 감소되는 구간은 교통효율과 사고 위험도 측면에서 체계적이고 합리적인 도로점용공사가 필요하지만, 국내의 도로 특성을 반영한 공사구간 도로상에서의 교통사고 측면의 연구가 부족하여 외국의 사례를 적용하고 있는데, 외국은 국가의 면적, 도로의 사정, 국민들의 의식수준 등 여러 가지 상황이 우리나라와 상이하여 외국의 사례를 그대로 적용했을 때에는 실제적으로 우리나라 도로현황과 일치하지 않는 경우가 대부분이다. 이에 고속도로 23개 노선을 중심으로 2003년부터 2005년까지 3년동안 교통통제가 이루어진 공사구간에서 발생한 교통사고를 조사하고 이 공사구간에서 발생하는 교통사고의 특성을 사고유형별, 사고심각도별, 공사유형별, 원인별, 사고 발생경향별, 그리고 전체 고속도로상의 교통사고와의 비교를 통해서 알아보고자 한다. 또한 이를 통해서 보다 구체적이고 세부적인 공사구간 통제지침의 필요성을 제시하고자 한다.