• 한국정보시스템학회지:정보시스템연구
• /
• 제13권1호
• /
• pp.59-75
• /
• 2004

Fixed-mobile convergence services can be defined as the combination of previously separate fixed and mobile services, and networks and commercial practices. Examples of fixed-mobile convergence services include single voice-mail box, single number and unified messaging across fixed and mobile networks. Recently as more voice is transferred to mobile networks, convergence services between fixed and mobile become more important. In Korea convergence services are only starting to become established, and are likely to become an important part of any operator's offering. In this paper, we search the different levels of fixed-mobile convergence services and the trends and regulations for fixed-mobile convergence services in major countries. And at the same time, we also suggest the corresponding Marketing strategies by operators related to fixed-mobile convergence services.

• 산업경영시스템학회지
• /
• 제10권16호
• /
• pp.143-147
• /
• 1987

Safety stocks constitute one of the major means of dealing with the uncertainties associated with variation in demand and lead time. Adeguate safety facilitate production activities and help to assure customers if good service on the other hand, carrying safety storks ties up working capital on goods that sit idle. The major problem of safety stocks management thus of consists of trying to achieve an optimal balance between the other carrying cost and the costs of stock shortage. Therefore, this study aims to find safety stock level of the fixed reorder quantity system and the fixed reorder cycle system of minimizing total cost when both demand and lead time are variable. (The distribution of demand and lead time is a mere assumption that follows the normal distribution) The results can be summarized as follows. i) Safety factor on the safety stock is determined by carrying cost and the costs of stock shortage: An optimal safety stick=the costs of stork shortage($C_s$) (the carrying cost($C_h$)+the costs of stock storage($C_s$). ii) The safety stock level of the fixed reorder quantity system is ($a{\;}_p\sqrt{L}{\sigma}$) under uncertainties. iii) The safety stock level of the fixed reorder cycle system is ($a{\;}_p\sqrt{R+L{\sigma}}$) under uncertain demand and constant lead time. ($a{\;}_p\sqrt{L{\sigma}_d{\;^2+{\mu}^2L{\sigma}^2}$) under demand and lead time uncertainties.

• 상하수도학회지
• /
• 제7권1호
• /
• pp.37-45
• /
• 1993

This research was performed to examined the applicability of a fixed-biofilm process for the wastewater treatment of military installations. Utilizing plastic net media, synthetic wastewater-average $BOD_5$ cocentration was $192mg/l$ treated in the three sets of reactors that have 8 hours, 6 hours, and 4 hours of hydraulic retention time. The results of this experiment showed that the biofilm was not detached easily, and the reactor was not closed by excess biomass. The average soluble $BOD_5$ concentrations of effluent were $6.0mg/l$ with 8 hours of retention time, $11.3mg/l$ with 6 hours of retention time, and $19.4mg/l$ with 4 hours of retention time. Especially it was reduced to $5.7mg/l$ in the second stage reactor with 4 hours of retention time. These resulted that the fixed-biofilm process could be adapted for the treatment of military installation wastewater.

• 정보처리학회논문지A
• /
• 제8A권2호
• /
• pp.117-124
• /
• 2001

At NOW (Networks Of Workstations), the load sharing is very important role for improving the performance. The known load sharing strategy is fixed-granularity, variable-granularity and adaptive-granularity. The variable-granularity algorithm is sensitive to the various parameters. But Send algorithm, which implements the fixed-granularity strategy, is robust to task granularity. And the performance difference between Send and variable-granularity algorithm is not substantial. But, in Send algorithm, the computing time and the communication time are not overlapped. Therefore, long latency time at the network has influence on the execution time of the parallel program. In this paper, we propose the preSend algorithm. In the preSend algorithm, the master node can send the data to the slave nodes in advance without the waiting for partial results from the slaves. As the master node sent the next data to the slaves in advance, the slave nodes can process the data without the idle time. As stated above, the preSend algorithm can overlap the computing time and the communication time. Therefore we reduce the influence of the long latency time at the network and the execution time of the parallel program on the NOW. To compare the execution time of two algorithms, we use the $320{\times}320$ matrix multiplication. The comparison results of execution times show that the preSend algorithm has the shorter execution time than the Send algorithm.

• 한국시뮬레이션학회논문지
• /
• 제25권2호
• /
• pp.75-81
• /
• 2016

고정위치 생산 방식과 이를 개선한 흐름 생산 방식의 생산성을 비교하기 위해 데크하우스 선행의장 공정의 사례를 이용하여 이를 비교 분석하였다. 현재의 선행의장 공정 시스템은 고정위치 생산을 하고 있으며, 여기서는 블록이 한 구역을 점유하고, 작업이 완료 될 때까지 이동하지 않는다. 반면 개선된 흐름생산시스템에서는 블록이 이동하며 작업자와 장비는 움직이지 않는다. 시뮬레이션 결과 제안된 생산시스템에서 블록의 이동시간과 대기시간을 고려하지 않았을 때는 블록의 생산량이 거의 증가하지 않았다. 그러나 흐름생산에서는 작업을 위한 장비와 작업자의 이동과 대기시간이 거의 없어, 작업장의 작업시간의 변동성을 줄일 수 있다면 흐름생산이 고정위치 생산 시스템을 대체하는 보다 더 우수한 대안이 될 수 있음을 보였다.

• 산업경영시스템학회지
• /
• 제13권22호
• /
• pp.1-6
• /
• 1990

This paper deals with software Release policy having a Fixed Operational period after a Software System is released. The underlying Software Reliability Growth is described by J-M Model Optimal of Software Release Time minimizing Total Expected Cost is Obtained.

• 산업공학
• /
• 제13권3호
• /
• pp.455-461
• /
• 2000

Logistics systems can be evaluated by how productively distribution center operates, how promptly transportation vehicle dispatches, how efficiently facility layout is, and so on. In this paper, a practical vehicle routing scheme with fixed delivery time and fixed vehicle routes is introduced. The method helps the distribution center reduce logistics cost with respect to dispatching vehicles, and satisfy the customer with pre-determined delivery time window constraints. A case study has shown that the proposed scheme not only generates a feasible schedule with time windows, but also balances material flow in warehouse.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2013년도 춘계 종합학술대회 논문집
• /
• pp.217-218
• /
• 2013

급성기 허혈성 뇌졸중 증상이 있는 뇌 관류 CT검사를 시행한 환자를 대상으로 장비사가 제시한 고정 시간 기법(fixed time technique)과 조영제 추적 기법(bolus tracking technique)을 비교하여 환자의 피폭선량을 분석하고자 하였으며 조영제 추적 기법의 유용성과 최적의 조영증강 구간을 구현하는 Time graph를 알아보기 위한 것이다.

• 한국IT서비스학회지
• /
• 제4권1호
• /
• pp.107-115
• /
• 2005

As Real Time Enterprise (RTE) has been spotlighted since the year of 2002, some advanced companies have been implementing the paradigm of RTE to its legacy systems and the number of the companies has been growing. However, the network infrastructures mainly based on fixed telecommunications network make the results of the RTE implementations fall short of their expectations. In this paper, we propose to construct the fixed-mobile convergence (FMC) environment to achieve RTE. The convergence infrastructure will improve user accessibility to all kinds of data and will encourage the users to interact with the systems.

• 한국통신학회논문지
• /
• 제28권9B호
• /
• pp.783-792
• /
• 2003

We consider a finite-buffer discrete-time queueing system with fixed-size bulk-service discipline: Geo/ $G^{B}$1/K＋B. The main purpose of this paper is to present a performance analysis of this system that has a wide range of applications in Asynchronous Transfer Mode (ATM) and other related telecommunication systems. For this purpose, we first derive the departure-epoch probabilities based on the embedded Markov chain method. Next, based on simple rate in and rate out argument, we present stable relationships for the steady-state probabilities of the queue length at different epochs: departure, random, and arrival. Finally, based on these relationships, we present various useful performance measures of interest such as the moments of number of packets in the system at three different epochs and the loss probability. The numerical results are presented for a deterministic service-time distribution - a case that has gained importance in recent years.s.