• Journal of The Korean Association For Science Education
• /
• v.18 no.3
• /
• pp.443-450
• /
• 1998

This study was performed to find the environmental factors of inquiry instruction perceived by secondary school science teacher. The instrument consisted of three domains such as teaching conditions, viewpoints of secondary school science teachers of environmental factors for inquiry instruction, and barrier and improve! rent factors of inquiry instruction. Teaching conditions between middle school and high school science teachers were not different significantly. Environmental factors of inquiry instruction of secondary school science teacher included five factors such as 'facilities and encouragement', 'amount of works and materials', 'teacher education and textbook', 'practice and knowledge' and 'perception of necessity and satisfaction'. And all factors except 'perception of necessity and satisfaction' were very low state for inquiry instruction. In the disturbant and improving factors, the critical factors were 'over students per class', 'textbook' and 'learning materials' for middle school science teachers, and 'over students per class', and 'entrance examination' for high school science teachers. Thus the development and diffusion of adequate inquiry learning materials may be helpful to practicing inquiry instruction as decrease of works and psychological charges, and it is needed to reorganize systematically and intensify pre- and in-service teacher education to practice inquiry instruction.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.10
• /
• pp.2627-2640
• /
• 1998

In this paper, we analyze the performance of the virtual cell system[1] for the transmission of IP datagrams in mobile computer communications. A virtual cell consistsof a group of physical cells shose base stationsl are implemented b recote bridges and interconnected via high speed datagram packet switched networks. Host mobility is supported at the data link layer using the distributed hierachical location information of mobile hosts. Given mobility and communication ptems among physical cells, the problem of deploying virtual cells is equivalent to the optimization cost for the entire system where interclster communication is more expesive than intracluster communication[2]. Once an iptimal partitionof disjoint clusters is obtained, we deploy the virtual cell system according to the topology of the optimal partition such that each virtual cell correspods to a cluser. To analyze the performance of the virtual cell system, we adopt a BCMP open multipel class queueing network model. In addition to mobility and communication patterns, among physical cells, the topology of the virtual cell system is used to determine service transition probabilities of the queueing network model. With various system parameters, we conduct interesting sensitivity analyses to determine network design tradeoffs. The first application of the proposed model is to determine an adequate network bandwidth for base station networking such that the networks would not become an bottleneck. We also evaluate the network vlilization and system response time due to various types of messages. For instance, when the mobile hosts begin moving fast, the migration rate will be increased. This results of the performance analysis provide a good evidence in demonsratc the sysem effciency under different assumptions of mobility and communication patterns.

• Journal of Korea Port Economic Association
• /
• v.34 no.4
• /
• pp.17-38
• /
• 2018

The purpose of this study is to establish shipping companies' selection factors related to a classification society and to explore the relative importance of each factor using the analytical hierarchy process(AHP) technique. Insufficient research exists on the hierarchial structure of shipping companies' factors of selecting a classification society. The factors are identified and classified into two tiers of major and detailed factors, by referring to the related industrial linkages, prior research related to the determinants, and the process and service delivery of the classification society's activities. The empirical analysis of this study is based on the relative importance of determinants when selecting a classification society, and experts engaged with shipping companies were surveyed using questionnaires. The results of the AHP methodology on the main factors of shipping companies in selecting a classification society are as follows. The relative importance of the main factors was 0.373 for technical and survey services, 0.284 for recognized organizations(RO) functions, 0.177 for cost and 0.167 for market(related industry) expectations. The relative importance of the detailed factors is 0.144 for the ability to respond to a port state control(PSC) inspection, 0.143 for technical services, 0.090 for the requirements of financial institutions/ shippers/shipyards, 0.087 for class maintenance costs, 0.086 for the survey network, 0.085 for surveyor competency, 0.072 for cooperation with IMO and government authorities, 0.067 for recognition for RO, 0.058 for the business power of the classification society, 0.052 for the initial inspection costs, 0.040 for reputation and trustworthiness, 0.038 for the costs related to the class, and 0.037 for connections to related industries.

• The KIPS Transactions:PartD
• /
• v.15D no.3
• /
• pp.375-386
• /
• 2008

Recently, development paradigm of information system is turning into object oriented and component based, and this methodology is leading the software industry. To acclimatize aptly to this trend, users demand the assessment of software expenses to change with the appropriate model of computing costs of the environment, and some people are actually studying the concept of Object Oriented Function Point and UCP method. Especially, Object Oriented Function Point Measurement Process has good points in overcoming the bound of LOC and the existing the Function Point Measurement Process because Object Oriented Function Point Measurement Process is applicable to the early stage of development project mainly with the used cases, and valid to the life long period as the each stage of software products develops, and always understandable to communicate with users by the UML mark rules. Accordingly, this research is to measure Functional Point at ROFP and AOFP in accordance with the development project of information system by the national defense CBD methodology procedures and UML Interrelation Analysis that are recently and widely used in the developmental environment of object oriented information system. Furthermore, this study suggests the measurement method to obtain Functional Point, and identifies service function and object/class function in the correlation analysis of use case and class based on the products and UML modeling via traditional FPA model and object oriented FPA model. Above all, this study is to demonstrate the improvement of traditional Function Point Measurement Process, IFPUG-CPM and software cost basis, and reveal Function Point Measurement Process, which is appropriate to the development of object oriented information system, and suggest the evaluation results of the compatibility through case studies.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.37 no.1
• /
• pp.12-22
• /
• 2000

This paper presents the window-based permit distribution scheme for efficient medium access control to support multiclass traffic in APON(ATM over passive optical network). The proposed MAC protocol considers the characteristics of QoS(Quality of Service) for various traffic classes. A periodic RAU(request access unit) in upstream direction, includes dedicative request fields for each traffic category within the request slot. The transmission of upstream cell is permitted by the proposed window-based spacing scheme which distributes the requested traffic into several segments in the unit of one spacing window. The delay sensitive traffic source such as CBR or VBR with the stringent requirements on CDV and delay, is allocated prior to any other class. In order to reduce the CDV, so that the permit arrival rate close to the cell arrival rate, Running-Window algorithm is applied to permit distribution processing for these classes. The ABR traffic, which has not-strict CDV or delay criteria, is allocated flexibly to the residual bandwidth in FIFO manner. UBR traffic is allocated with the lowest priority for the remaining capacity. The performance of proposed protocol is evaluated in terms of transfer delay and 1-point CDV according to various offered load. The simulation results show that our protocol has the prominent improvement on CDV and delay performance with compared to the previous protocol.

• Journal of Advanced Navigation Technology
• /
• v.27 no.6
• /
• pp.835-840
• /
• 2023

RFID(Radio Frequency Identification) systems are attracting attention as a key component of Internet of Things technology due to the cost and energy efficiency of application services. In order to use RFID technology in the IoT application service field, it is necessary to be able to store and manage various information for a long period of time as well as simple recognition between the reader and tag of the RFID system. And in order to read and write information to tags, a performance improvement technology that is strong and reliable in poor wireless channels is needed. In particular, in the UHF(Ultra High Frequency) RFID system, since multiple tags communicate passively in a crowded environment, it is essential to improve the recognition rate and transmission speed of individual tags. In this paper, Middleton's Class A impulsive noise model was selected to analyze the performance of the RFID system in an impulsive noise environment, and FM0 encoding and Miller encoding were applied to the tag to analyze the error rate performance of the RFID system. As a result of analyzing the performance of the RFID system in Middleton's Class A impulsive noise channel, it was found that the larger the Gaussian noise to impulsive noise power ratio and the impulsive noise index, the more similar the characteristics to the Gaussian noise channel.

• Journal of Families and Better Life
• /
• v.28 no.1
• /
• pp.131-143
• /
• 2010

The purpose of this study is to understand the living culture of transnational married women and to analyze the out door play of children in their hometown. The data was collected through observation from 27th June to 7th July 2008 in Jian, Jilin Province China. The children's play and lifestyles were observed, and data pertaining to the culture of the people were collected by a teacher and staff. We also visited the residents for housing information. The results are given below. 1. They dressed in Korean clothes on festive days and the boys put on a hood. They had eating habits which included cooking for themselves or buying semi-manufactured goods but did not use, instant food. The housing habits involved a combination of cooking and heating by Korean floor heating system(Ondol). They utilized outdoor space to grow vegetables. Those with a fulltime job(teacher) preferred to live in an apartment but an apartment was too expensive. Public utility charges and traffic expenses were cheap. 2. The main festive days are the lunar New Year's Day and Chuseok. The children returned home and enjoyed the festive day with their parents. The language used are Korean language and Chinese. Some Korean words and phrases in Jian Joseonjok have different meanings as compared to how they are used in Korea. A capping ceremony did not to celebrate becoming an adult from an adolescent. Couples performed a wedding ceremony at a wedding hall attended by their parents and invited relatives from both families. The relatives gave the couple a wedding gift. They did not go on a wedding trip as it was not affordable but instead spent their wedding night at a hotel in this culture. When someone dies, they bury the body after cremation. They perform a memorial service for three years on the birthday of the departed. They have a banquet on the 60th birthdays with their relatives and neighbours and are typically presented with a carp for longevity. 3. They understand capitalism and therefore send their children to school to improve their social position. The Korean and Chinese languages are required subjects in school. The students choose a second language(English or Russian). They prefer English class but at the time of this study an English class was not offered at the school in Jian Joseonjok. Therefore the children entered a Chinese school. 4. The children play outdoor games such as Y$\acute{a}$o J$\grave{i}\bar{a}$(要家), X$\grave{i}$ang g$\grave{i}$(象棋), T$\grave{i}\grave{a}$o p$\acute{i}$ j$\grave{i}$n(r)(跳皮節), D$\grave{o}$uch ing g$\grave{u}$n 凍冷根, B$\bar{e}$i B$\bar{e}$i 背背, and soccer. They play games according to the season.

• Journal of Educational Research in Mathematics
• /
• v.19 no.4
• /
• pp.545-564
• /
• 2009

TPACK (Technological Pedagogical Content Knowledge) adds the technological knowledge to PCK (Shulman 1986), completing the combination of three kinds of knowledge, i.e. teacher's content knowledge (CK), pedagogical knowledge (PK), and technological knowledge (TK). In this study, I seek to design methodological ways to improve TPACK for preservice mathematics teachers by developing and analyzing team project-based classes with technology in a class of the first semester 2009 in a teacher's college in Seoul, South Korea. The goal of the team project is to design classes to teach mathematics with technology by selecting technology tools suitable for specific mathematical concepts or mathematics sections. In the early stage of the class in the college, the confidence levels among the preservice mathematics teachers were relatively low but increased in the final stage their mathematics teaching efficacy up to from 3.88 to 4.50. Also, the pre service mathematics teachers answered the team project was helpful or very helpful in developing TPACK; this result proves that lectures with technology which based on team project are excellent tools for the teacher to design classes with technology confidently. Considering the teacher's TPACK is one of the abilities to achieve the goals required in the information technology era, the preservice mathematics teachers are asked to plan and develop the lectures with technology, rather than just taught to know how to use technology tools or adapt to specific cases. Finally, we see that national-wide discussion and research are necessary to prepare customized standards and implementable plans for TPACK in South Korea.

• Korean Journal of Poultry Science
• /
• v.32 no.1
• /
• pp.29-34
• /
• 2005

This study was conducted to estimate the effects of genotype for chicken major histocompatibility complex (MHC) B-LB genes on economic traits. To detect polymorphism, 400 bp fragments of MHC B-LB genes were obtained and sequenced. After digestions using restriction enzyme Hea III, two restriction enzyme sites were observed. There were two mutations at position 427 and 651 those were decided as Type I and Type II, respectively. Using RFLP analyses, type I were genotyped to TT, TC and CC, and type II to MM, Mm and mm. The relatively higher TC genotype frequencies (0.8) of Type I and Mm genotype frequencies (0.88) of Type II were observed in Korean native chickens. The effects of the genotype on 150 days body weight trait were investigated by the associations of CC and Mm genotypes (P<0.05) in Korean native chickens. This result suggests that a significant association exists between the SNP and 150 days body weight.

• Journal of Science Education
• /
• v.36 no.1
• /
• pp.94-105
• /
• 2012

The purposes of this study is to identify the professional knowledge of the three elementary teachers for science-gifted students in teaching method. All teachers have received in-service program in gifted education, and have been recommended by their colleagues. Two teachers have instructed the gifted for more than five years, one teacher have instructed the gifted for one year and the general students for eleven years. For for this study, each teacher's lesson plans were collected, videotapes were recorded during lessons, and in-depth interview for each participant were conducted. All recoded data were transcribed and analyzed. Some unique characteristics of teaching method for the gifted were identified from the class instruction of participants. They had knowledge of teaching model for the gifted, especially Renzulli's three pod enrichment model. And they mainly used the materials developed by KEDI for the gifted. Also they had capability to be able to reconstruct them, but their lesson plans did not be realized well in their class. Some implications from findings of this study were suggested, such as teaching methods to improve the quality in the classes of the gifted in science.