• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.7B
• /
• pp.433-439
• /
• 2005

In this paper, we propose a Flow Based Waiting Time Priority (FB-WTP) scheduler that supports the proportional delay differentiated services between classes. Existing scheduling algorithms utilize the configuration of scheduler, which is operated as class unit, applied to wired network. However, FB-WTP scheduler is operated as flow unit and can take advantage of multi-flow diversity effect in time-varying channel state environment. As a result, FB-WTP improves the average queueing delay on each class as well as supporting the average queueing delay ratio between classes. It also solves the HOL packet blocking problem implicitly. Simulation results show that FB-WTP scheduler has better system queueing delay performance than Look-ahead Waiting Time Priority (LWTP) scheduler and supports the larger queueing delay ratio between classes that network operator set.

• Journal of the Korea Society of Computer and Information
• /
• v.7 no.2
• /
• pp.59-67
• /
• 2002

Major Characteristic of the 7th National Curriculum in science is to provide deep and supplementary learning, depending on the level of each learner. In the level-oriented curriculum, coursewares are used to present teaching materials to various levels. In most coursewares, however, they provide their contents at a uniform level and hence it is hard to expect level-oriented learning. This paper presents learner's modeling for developing student's level-oriented dynamic tutoring system for science class , Instructional module of this system made by component unit is able to be reconstructed dynamically. Learning module is constructed using a hybrid model mixed of Overlay and Bug model. Testing module interprets diagnostic errors to be established by given differentiated weight in accordance with item's difficulty and discrimination. Through ITS student modeling, this system presents various problem solving methods reconstructed by learner's level differentiated.

• 한국사회정책
• /
• v.25 no.2
• /
• pp.281-304
• /
• 2018

This paper aims at analysing what impacts the experience of self-employed business have had on the income mobility. Since 2000s, the flexibilization of labor market and the population aging led to the increase of the number of self-employed job as many retirees at the age of early 50s has set up the self-employed business as a bridge job. However, previous researches just have emphasized on the impoverishment of the self-employed, but not focused on what different effects the experience of self-employed had on the income class mobility by age group. This paper compares the difference in the income class mobility by age group and employment status, and analyses its longitudinal trends. According to the result, as a whole the experience of self-employed has positive effect on the upper mobility of income class, but it become disadvantageous for the upper mobility as the age goes up. When belonging to the age group over 60s, the experience of self-employed rather increases the risk of lowering income class. Just as the experience of self-employed has different effects on income class mobility by age group, so the differentiated measures for age groups are demanded.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.12
• /
• pp.1505-1516
• /
• 2001

The goal of Medical multimedia server is to develop computer hardware and software which would enable electronic access, storage, transmission, and display of patient data and images. Since the current network only provides so called "best-effort" services, it is impossible to satisfy QoS guarantee that is required for real time application services for emergency room, operating room etc. Accordingly, world-wide research is being made for a variety of services to provide QoS. he goal of DiffServ is to offer scalable differentiated service in Internet which are made possible by traffic classification and conditioning only performed at an edge(or a boundary) node. In case DiffServ was deployed in the Medical multimedia network, it is difficult to estimate how the QoS mechanism would affect totally the network performance. Therefore, we need to verify by simulation the design of algorithm which provide a variety of differentiated services. In QoS for Medical multimedia network, a simulator is designed and implemented using OPNET to investigate the performance of DiffServ QoS support mechanism. The developed DiffServ simulator may generate packets according to random, and bursty traffic models in order to incorporate diverse traffic conditions in the Medical multimedia network environment. Based on our simulation results, we confirmed that service differentiation is possible by using the EF(Expedited Forwarding) class in DiffServ networks.

• Journal of Internet Computing and Services
• /
• v.2 no.2
• /
• pp.23-36
• /
• 2001

To support real-time multicast, the existing DS network may use the EF PHB for transmission, However, because of the dynamic characteristics of the multicast flow and the features of the EF PHB. it is very difficult to make a provision of resources or to manage the network when EF multicast flows increase, Also, the existing LBE PHB can not guarantee the transmission delay bounds required for the real-time multicast traffic, In this paper. a new concept of PHB. namely, low-delay multicast PHB, that may guarantee approximately the per-hop delay is proposed, For the low-delay multicast PHB, router architectures are devised, The queue management algorithm on a low-delay multicast queue and a scheduling method are also devised. This new architecture of the LDM AF class is simple to be implemented.

• Journal of Digital Convergence
• /
• v.10 no.4
• /
• pp.251-256
• /
• 2012

In this paper, we addressed the problem of upstream bandwidth in EPONs. We presented a wavelength division EPON supporting QoS in the differentiated services framework. It was shown that the bandwidth allocation by priority scheduling, under our assumptions for traffic behavior, will result in an unexpected behavior for high priority class and we suggested the use of weighted priority scheduling to alleviate this problem. Our wavelength division EPON supporting QoS allocates effectively and fairly bandwidths and wavelengths between ONUs in the differentiated services framework. Moreover, we showed better performance in terms of average and maximum end-to-end delay, as well as network throughput, utilization compared with some other algorithms. We used simulation experiments to study the performance and validate the effectiveness of the proposed network and algorithm.

• School Mathematics
• /
• v.14 no.3
• /
• pp.315-330
• /
• 2012

Mathematics educators have tried to teach mathematics to all students who are at any mathematical level by differentiated math instruction from late 1990s in Korea. The common differentiated math instruction separates students into two or three groups according to their mathematical ability and then different activities and tasks are given to each group. This kind of instruction fosters negative attitudes to mathematics to low level students and fix them at low level. So I investigated new mathematics instruction considering able students and low attainers at the same time. This new method is based on using open problems in math class. All students can respond to an open problem in different ways. If teachers could relate all varieties of answers got from students at every level to build good understanding the concept which the problem target at, low attainers could move to their potential developmental levels. This kind of instruction can change low math attainers' negative attitudes to good ones to mathematics and foster their confidence in performing mathematics.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.11C
• /
• pp.10-23
• /
• 2001

It is difficult to satisfy the QoS(Quality of Service) guarantee which is required by real-time application services only with the Best-Effort(BE) service adopted in the current Internet. Therefore, worldwide research is being made on the method of QoS provisioning. Among them, the QoS guarantee mechanism using the Diffserv(Differentiated Service) was discussed in this paper. First we analyzed how the DiffServ performance was affected by traffic models. For this, we performed the research for the random, bursts, and self-similar traffic modeling method. We then designed and implemented an OPNET simulator, and performed the simulation 7d performance evaluation for diverse input parameters. Based on the results of performance evaluation, it was confirmed that QoS guarantee is possible for the EF(Expedited Forwarding) class with the DiffServ function under every environments considered and the service separation between EF and BE(Best Effort) classes is also possible. We also analyzed the performance variation and dynamic behavior of DiffServ mechanism based on the resource allocation between E? and BE classes in WFQ(Weighted Fair Queueing).

• Korean Journal of Social Welfare Studies
• /
• v.45 no.3
• /
• pp.151-178
• /
• 2014

Highly Differentiated and segmented social insurance scheme in Taiwan shows its salient dimension of stratification, which has been considered as a general feature of conservative welfare regime. However, compared to Western conservative welfare states, Taiwan's social insurance scheme shows a distinct feature. First, Taiwan's social insurance scheme has offered a full coverage for various benefits. Secondly, Labor Insurance and Government employees' Insurance reveal distinct features of stratification. Labor Insurance has developed a universalistic system based on status equality and cross-class solidarity of working classes while Government employees' Insurance includes a myriad of occupational- and status-based programs. This article aims to articulate the historical origin of Taiwan's unique social insurance scheme and explains it as an unintended result of state's political intervention and various interests of each insured groups, especially, politically, economically, and ethnically conflicting identities of government employees and working classes.

• Journal of the Korean Institute of Educational Facilities
• /
• v.8 no.5
• /
• pp.5-16
• /
• 2001

This paper presents results from analysis of architectural plan drawings of 355 elementary schools recently designed for 4 years. Theses plans are analyzed by factors such as local distribution, number of classes, type of plan, total construction area, area per a class, area per a student, and area status of each space. The purpose of this study is to provide fundamental resources for architectural designing and planning of elementary schools through finding trend and status of elementary school buildings that have no detailed data of area index. The results of this study are as follows: 1. As a result from analyzing number of classes in the surveyed schools, schools having 36 classes are dominant and schools having 72 classes are also shown. Average number of classes is 34.1. This result reflect s that elementary schools have been planned as large-scale schools. 2. In terms of type of plan, we found out that instead of disappearing traditional single corridor type building, the open school building that have multi-purpose spaces are mainly designed. In addition to that, there are few schools with large class rooms. 3. In the status of area of each school, they have much larger areas than areas provided by building guidelines. Secondly, there are some schools with two times area difference even though they have same class number. Therefore, it needs to adjust the school building guidelines to practical needs in the consideration of elementary school building for compulsory education. Though the plans of recently designed school for 4 year s are more differentiated than past, there are few schools planned by appropriate plan design and area distribution scheme. As a consequence, some improvements like improvement of building guidelines are desperate.