• 조명전기설비학회논문지
• /
• 제23권4호
• /
• pp.47-55
• /
• 2009

본 논문에서는 해석적방법론에 의한 산업용 수용가의 공급지장비를 산정할 수 있는 방법론을 개발하기 위해 산업용 수용가 1,026호를 방문하여 설문조사를 수행하는 미시적 접근법을 사용하여 산업용 수용가의 종별 공급지장비를 표준산업분류에 의한 18개의 업종으로 조사하였다. 얻어진 조사결과를 계층화의사 결정법(AHP; Analytic Hierarchy Process)으로 최적의 공급지장비용 함수(SCDF; Sector Customer Demage Function)를 선정하였다. 이를 통하여 배전계통에서의 신뢰도 가치평가(VBDRA; Value Based Distribution Reliability Assessment)를 위해서 주어진 배전계통 예상 공급지장에너지(EENS; Expected Energy Not Supply), 정전비용기대치(ECOST; Expected Interruption Cost), 차단에너지비율(IEAR; Interrupted Energy Assessment Rate)을 계산하여 그 가치를 평가하였다. 이를 배전계통에 적용하기 위해서 사례연구로 적용하고 공급지장비용을 도출하여 그 특성을 분석하였다.

• 대한전기학회논문지:전력기술부문A
• /
• 제53권1호
• /
• pp.22-30
• /
• 2004

As an information-oriented society comes, many people use PC and depend on database that network server has. However, the online data can be missed when a blackout happens and also a power failure effects on standard of judgment on Power Quality. Thus, it is reason of a trend using interruption-free live-line work when a trouble happens to power system. However, the 83％ among the number of people who receive an electric shock experience when a laborer is doing interruption-free live-line works. In interruption-free method, the education and the training problem has been issued. However, we have a few instructors for that training. Furthermore, the trainees have short training period, just 4 weeks. In this paper, to develope the method that has no restriction of a time and place and reduce the wasteful materials, immersion type virtual reality(or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by doing same action in the real safe environment. Thus, it can be valuable to apply this training system to a dangerous work like as "Interruption-free live-line work exchanging COS(Cut-Out-Switch)". In this program, the user works with a instruction on the window and speaker and can't work other tasks until each part of the task completed. The workers using this system can use their hands and viewpoint movement as he is in a real environment but the trainee can't use all parts and senses of a real body with the current VR technology. Despite of this weak point, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has a high potentiality.

• 상하수도학회지
• /
• 제31권6호
• /
• pp.511-519
• /
• 2017

Multi-regional water supply system, which installed for supplying multiple water demands, is characterized by large-sized, long-distance, tree-type layout. This system is vulnerable to long-standing service interruption when a pipe breaks is occurred. In this study, a numerical method is proposed to calculate drainage time that directly affects time of service interruption. To begin with, governing equations are formulated to embed the delayed drainage effect by the friction loss, and to resolve complicated connection of pipelines, which are derived from the continuity and energy equations. The nonlinear hydraulic equations are solved by using explicit time integration method and the Newton-Raphson method. The developed model is verified by comparing the result with analytical solution. Furthermore, the model's applicability is validated by the examples of pipelines in serial, in parallel, and complex layout. Finally, the model is utilized to suggest an appropriate actions to reduce the deviation of draining time in the C transmission line of the B multi-regional water supply system.

• 대한전기학회논문지:전력기술부문A
• /
• 제52권8호
• /
• pp.457-462
• /
• 2003

This paper presents an optimal operating strategy of distributed generation (DG) with reliability worth evaluation of distribution systems. Using DG for peak-shaving unit could reduce the overall system operating cost, and using DG for standby power unit could reduce the customer interruption cost. If DG operating cost is less than utility power cost in peak time, DG should be running to reduce the overall system operating cost. When customer interruption cost enlarges, however, standby power strategy may be the better operating strategy than peak-shaving strategy. Selection of whether DG should be operated for peak-shaving or for standby power, needs the accurate reliability worth evaluation and the accurate power cost evaluation. Instead of using annual average reliability worth, the concept of hourly reliability worth is introduced in this paper to determine the optimal operating decision of DG. Applying suggested hourly reliability worth, the distribution companies that possess DG could set up the optimal operating strategy of DG.

• 국제학술발표논문집
• /
• The 1th International Conference on Construction Engineering and Project Management
• /
• pp.699-704
• /
• 2005

Normally, monetary penalties for breach of agreement will be stipulated in the contract. The contractor parties, who fail to fulfill the agreement, are required to pay the other parties a certain amount or proportion of money as a fine. However, it is worth our study - whether or not the scope of monetary penalty implementation and bases for determination of a fine will cover the losses of social and administrative costs incurred by the interruption of the contract. This research is about the best timing for government to cancel the freeway repair work contracts. Under the goal of the maximum social welfare, the limitation of government spending for the social and administrative costs invoked by interruption of contracts will have to be considered to attain the best timing of contracts' suspension or deferment. According to the factors of social and administrative costs, the best time point is calculated to reduce the loss of the aforesaid costs, which can also be used as theoretical basis for the future road-widening construction at home.

• ETRI Journal
• /
• 제43권3호
• /
• pp.447-458
• /
• 2021

The quality of experience (QoE) of video streaming is degraded by playback interruptions, which can be mitigated by the playout buffers of end users. To analyze the impact of playout buffer dynamics on the QoE of wireless adaptive hypertext transfer protocol (HTTP) progressive video, we model the playout buffer as a G/D/1 queue with an arbitrary packet arrival rate and deterministic service time. Because all video packets within a block must be available in the playout buffer before that block is decoded, playback interruption can occur even when the playout buffer is non-empty. We analyze the queue length evolution of the playout buffer using diffusion approximation. Closed-form expressions for user-perceived video quality are derived in terms of the buffering delay, playback duration, and interruption probability for an infinite buffer size, the packet loss probability and re-buffering probability for a finite buffer size. Simulation results verify our theoretical analysis and reveal that the impact of playout buffer dynamics on QoE is content dependent, which can contribute to the design of QoE-driven wireless adaptive HTTP progressive video management.

• KIEE International Transactions on Power Engineering
• /
• 제4A권4호
• /
• pp.171-177
• /
• 2004

In the current age of the information oriented society in which we live, many people use PCs and are dependant on the databases provided by the network server. However, online data can be missed during the occurrence of a blackout and furthermore, power failure can greatly effect Power Quality. This has resulted in the trend of using interruption-free live-line work when trouble occurs in a power system. However, 83% of the population receives an electric shock experience when a laborer is performing interruption-free live-line work. In the interruption-free method, education and training problems have been pinpointed. However, there are few instructors to implement the necessary training. Furthermore, the trainees undergo only a short training period of just 4 weeks. In this paper, to develop a method with no restrictions on time and place and to ensure a reduction in the misuse of materials, immersion type virtual reality (or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by performing the equivalent action in a safe environment. Thus, it can be valuable to apply this training system to such dangerous work as 'Interruption-free live-line work exchanging COS (Cut-Out-Switch)'. In this program, the user carries out work according to instructions displayed through the window and speaker and cannot perform other tasks until each part of the task is completed in the proper sequence. The workers using this system can utilize their hands and viewpoint movement since they are in a real environment but the trainee cannot use all parts and senses of a real body with the current VR technology. Despite these weak points, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has high potentiality.

• 한국산학기술학회논문지
• /
• 제19권12호
• /
• pp.416-431
• /
• 2018

본 연구의 목적은 간호사들의 병원 근무 경험과 경력단절 영향요인을 심층적으로 분석하기 위해 시도되었다. 이를 위해 26-55세 경력단절 간호사 20명을 대상으로 간호사로서의 경험, 간호 일의 특성과 퇴직사유의 내용을 인터뷰하였으며 현상학적 방법 중 꼴라쥐(Colaizzi)의 분석방법을 적용하였다. 분석결과 104개의 주요 진술과 17개의 구성된 의미, 6개의 공통 주제군, 2개의 범주가 도출되었다. 2개의 범주는 간호 업무 특성과 근무 환경 특성이며 간호 업무 특성에서는 '시간 압박', '자율성 부재', '신체 감정 노동', '낮은 임금 상승률'의 4가지 공통 주제군이, 근무 환경 특성에서는 '물리적 환경', '인적 환경'의 2가지 공통 주제군이 각각 도출되었다. 따라서 간호사의 경력단절 현상을 개선하기 위해서는 과도한 업무강도를 완화하고 적정수준의 임금인상과 안전한 근무환경을 제공하려는 노력이 필요하다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권14호
• /
• pp.5653-5657
• /
• 2014

Background: To evaluate factors which effect treatment interruption during concurrent chemoradiotherapy (CCRT) and overall survival in patients with uterine cervical cancer stage IB2-IVA in Srinagarind Hospital. Materials and Methods: Between January 2006 and December 2007, 107 patients with stage IB2-IVA as FIGO staging, 2000, were treated with CCRT in Srinagarind Hospital. Factors which caused treatment interruptions and impacted on overall survival were reviewed and analyzed. Results: Twenty of 107 patients had treatment interruption during CCRT in patients with uterine cervical cancer stage IB2-IVA in Srinagarind Hospital. The causes of treatment interruption were as follows: hematologic toxicity was found in 16 of 20 cases, 12 cases with grade 2 and 4 cases with grade 3; three of 20 cases had gastrointestinal toxicities, 1 case with grade 2 and 2 cases with grade 3; one case had grade 3 skin toxicity. The mean total treatment time of the uninterrupted and interrupted groups were significantly different (78.98 days vs 161.80 days, p <0.001). The patients who could tolerate ${\geq}5$ cycles of cisplatin administration had significantly higher mean white blood counts (WBC) ($9,769cells/mm^3$ vs $7,141cells/mm^3$, p=0.02). The mean initial hemoglobin (Hb) in the uninterrupted group was significantly higher than the interrupted group (11.5 mg% vs 10.3 mg%, p=0.03). Other factors including age, KPS, initial platelets, initial serum creatinine levels showed no statistical significance. The 3-year overall survival of the uninterrupted group was better than in the interrupted group (78.6% vs 55.0%, p=0.03). Conclusions: The initial Hb and WBC levels were significantly correlated with treatment interruption during CCRT in patients with uterine cervical cancer. The 3-year overall survival of the uninterrupted group was significantly better than interrupted group. These factors may then be used indirectly to predict the outcomes of treatment.

• ETRI Journal
• /
• 제44권3호
• /
• pp.361-378
• /
• 2022

In 5G, the required target for interruption time during a handover (HO) is 0 ms. However, when a handover failure (HOF) occurs, the interruption time increases significantly to more than hundreds of milliseconds. Therefore, to fulfill the requirement in as many scenarios as possible, we need to minimize HOF rate as close to zero as possible. 3GPP has recently introduced conditional HO (CHO) to improve mobility robustness. In this study, we propose "ZEro handover failure with Unforced and automatic time-to-execute Scaling" (ZEUS) algorithm to optimize HO parameters easily in the CHO. Analysis and simulation results demonstrate that ZEUS can achieve a zero HOF rate without increasing the ping-pong rate. These two metrics are typically used to assess an HO algorithm because there is a tradeoff between them. With the introduction of the CHO, which solves the tradeoff, only these two metrics are insufficient anymore. Therefore, to evaluate the optimality of an HO algorithm, we define a new integrated HO performance metric, mobility-aware average effective spectral efficiency (MASE). The simulation results show that ZEUS provides higher MASE than LTE and other CHO variants.