• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.297-304
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• 2013

Due to its excessive $CO_2$ emissions, road transport sector becomes a target for emission reduction strategies. Although precise and reliable emissions inventories are necessary for evaluating plans and strategies, developing the region-wide inventory is a difficult task mainly because of a lack of data including travel patterns and modal volumes in the reginonal context. Most existing inventory methodologies employ fuel sale data within the target region, which ignores actual regional traffic patterns and thus not suited to its geographical context. To overcome these problems, this study develops region-wide $CO_2$ emissions inventory methodology by utilizing the Korea Transport DB (KTDB). KTDB provides a number of useful information and data, such as road network with which one can identify in and out trips over the entire region, traffic volumes of various modes, distance of travel, travel speed and so on. A model of equations that allow the computation of volume of $CO_2$ emitting from the road transport activities within the target region is developed. Using the model, numerical analyses are performed for the case of Busan Metropolitan City to demonstrate the applicability of the developed model. This study is indeed exploratory in the sense that using the existing data, it develops the $CO_2$ emissions inventory methodology which can produce better results than those from conventional fuel sales methodology. This study also suggests further reresarch directions to develop more refined methodologies in region-wide basis.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.629-635
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• 2007

Reduced crew performance is frequently cited as a major causal factor in maritime accident causation. Although considerable research has been conducted on the hours of work undertaken by seafarers through interviews and the analysis of records, experimental studies to observe the effects of factors such as high workload, shift patterns, stress, sleep deprivation and disturbance on the cognitive performance of mariners have been limited. Other safety-critical transport industries, such as aviation and rail, have developed fatigue management tools to help manage the work patterns of their operators. Such a tool for mariners would assist shipboard crew, marine pilots and shore management in planning and improving work schedules. The overall aim of this paper is to determine a fatigue factor, which can be applied to human performance data, as part of a software program that calculates total cognitive performance. This program enables us to establish the levels of cognitive performance of a group of marine pilots to test a decision-making task based on radar information. This paper addresses one of the factors that may contribute to the determination of various fatigue factors: the effect of different work patterns on the cognitive performance of a marine pilot.

• Journal of Educational Research in Mathematics
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• v.15 no.1
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• pp.75-105
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• 2005

This study explored a mathematical modeling flow and the effect of interactions among students and between a student and Excel on modeling in a small group modeling environment with Excel. This is a case study of three 8th graders' modeling activity using Excel during their extra lessons. The conclusions drawn from this study are as follows: First, small group modeling using Excel was formed by formulating 4∼10 modeling cycles in each task. Students mainly formed tables and graphs and refined and simplified these models. Second, students mainly formed tables, algebraic formulas and graphs and refined tables considering each variable in detail by obtaining new data with inserting rows. In tables, students mainly explored many expected cases by changing the values of the parameters. In Graphs, students mainly identified a solution or confirmed the solution founded in a table. Meanwhile, students sometimes constructed graphs without a purpose and explored the problem situations by graphs mainly as related with searching a solution, identifying solutions that are found in the tables. Thus, the teacher's intervention is needed to help students use diverse representations properly in problem situations and explore floatingly and interactively using multi-representations that are connected numerically, symbolically and graphically. Sometimes students also perform unnecessary activities in producing data by dragging, searching a solution by 'trial and error' and exploring 'what if' modeling. It is considered that these unnecessary activities were caused by over-reliance on the Excel environment. Thus, the teacher's intervention is needed to complement the Excel environment and the paper-and-pencil environment properly.

• Korean Journal of Cognitive Science
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• v.26 no.1
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• pp.27-51
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• 2015

The present study tested the effect of a top-down influence on recalling the colors of Stroop words. Participants remembered the colors of 1, 2, 3 or 6 Stroop words. After 1 second of a memory delay, they were asked to recall the color of a cued Stroop word by selecting out its corresponding color on a color-wheel stimulus. The correct recall was defined when the participants chose a color that was within ${\pm}45^{\circ}$ from the exact location of Stroop word's color on the color-wheel. Otherwise, the recall was defined as incorrect. The analyses of the frequency distribution of the participants' responses in the error trials showed that the probability of choosing the color-name of the target Stroop word was higher than the probability of other five color-names on the color-wheel. Further analyses showed that increasing the number of Stroop words to manipulate memory load did not affect the probability of the Stroop interference. These results indicate that the top-down interference by Stroop manipulation may induce systematic distortion of the stored representation in visual working memory.

• Korean Journal of Cognitive Science
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• v.23 no.1
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• pp.1-23
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• 2012

This study investigated the lexical access processing of inflected Korean verbs in the mental lexicon. In Korean, verbs can be classified into two main types of inflections, which are regular and irregular inflections, which can be further divided into three types of regular inflections and two types of irregular inflections. A masked priming lexical decision task was used and the priming effects were compared. Experiments were carried out using the five different types of verbal inflections in Korean: (1) No change-regularity (regular verbs with no orthographical or phonological changes), (2) Phonological change-regularity (regular verbs with phonological changes to the stem only), (3) Orthographical change-regularity (regular verbs that only undergo orthographical changes), (4) Stem change-irregularity (the stem is omitted or alternated with the other phoneme of the stem in irregular verbs), (5) Ending change-irregularity (irregular verbs with changes in the endings by phoneme substitution). The first three types are regarded as regular verbal inflections whereas the latter two types are regarded as irregular verbal inflections. The infinitive forms of the verb were presented as target words and three different conditions were presented as prime words. The three conditions included regular verbal inflection, irregular verbal inflection, and a control condition in which morphologically and semantically unrelated primes were presented. In addition, different stimulus onset asynchrony (SOA) were manipulated (43ms, 72ms, 230ms) to examine the time frame of the morphological decomposition process in word recognition. The results revealed that there were significant priming effects in all three SOAs across conditions. Hence, there was no significant differences in priming effects between regular and irregular verbal inflection conditions. This may suggest that Korean verb processing does not adopt different processing routes for regular and irregular inflections, which can also be an indication of earlier morphological information processing for Korean verbs.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.5
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• pp.146-153
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• 2009

Recently, the research relative to NGN(Next Generation Network) is progressing in 3GPP(The 3rd Generation Partnership Progect), IETF(Internet Engineering Task Force), and so on. Although user needs frequently mobility which is various service pattern, In accordance with the development of these various applications, IMS(IP Multimedia Subsystem) and hierarchical networks ie, Femtocell/WiBro/3G etc is constructed for more user demands which provide service in anytime, anywhere. It is necessary to optimum network selection criterion which consider to wireless signal quality add to user service profile and service network traffic balance. NGN also needs a method to perform heterogeneous handover and to constraint Ping-pong phenomenon when using existing terminal-based handover decision. This paper proposes scheme for network selection and heterogeneous handover procedure in hierarchical wireless multi-access network based on SIP-MIH(Session Initiation Protocol-Media Independent Handover) with IMS by using user service profile that the considerations are dealing with not only selection and registration of various access network but also easy of developing the terminal.

• Korean Security Journal
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• no.32
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• pp.123-150
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• 2012

The purpose of this study was to seek practical intelligences for certain persons who wish to be a guard by studying for what practical public guards' recognition of organization and vocation is. The results of this study were as follows. First, Six study participants presented 'Respect within members', 'Atmosphere like family', 'Premium members', and 'Economic compensation & wealth of budget' as essential requirements for the best guard organization. Second, they also presented 'Systematic daily task & training', 'Exact selection system', and 'Strong cohesion & teamwork' as strong points of their organization. Third, they mentioned 'Internal evaluation system', 'Lack of education contents', and 'Limited position circulation' as weak points of their organization. Fourth, they mentioned that they feel encouraged itself as they work in the best guard organization, while they were skeptical when the citizens did not cooperate with them and they were not fully rewarded for their injury. Fifth, they expressed 'Difficulty of business cooperation', 'Unstable living patterns', 'Inconsistent assessment', and 'Continuing tension' as difficulties for performing the duties and stress causes. Lastly, they recognized of job security and self-esteem as they work in the best guard organization as advantages of a job, while they recognized of controlled life, low salaries and welfare level compared to duty importance and risks as disadvantages of a job. Consequently, students who wish to be a guard should consider job and organization attributes and set their career goals refer to these results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.56-62
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• 2010

The purpose of this study was to compare the difference of driving pattern between male and female drivers for a straight driving and unexpected situation using driving simulator and motion data. The participants included total 60 university students; 30 males aged 24.3$\pm$1.4 years and 30 females aged 23.2$\pm$1.9 years with 1~3 years of driving experience. The driving task required participants to keep the constant distance (20m, 25m or 30m) with preceding vehicle running at 55~65km/hr speed using driving simulator which was programed unexpected situation for two minutes. Simulator and motion data were acquired. The acquired data was divided in straight driving block for 40 second and unexpected situation block for 2 second. The coefficient of variation (CV) of lane keeping and jerk-cost (JC) function were analyzed for straight driving and unexpected situation blocks. The results show that CV was smaller in males than females for both straight and unexpected situation blocks (p < .05). JC was smaller in females than males for both straight and unexpected situation blocks. As the distance of vehicles become longer, JC was smaller for both male and female (p < .05).

• Journal of The Korean Association For Science Education
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• v.30 no.6
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• pp.752-769
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• 2010

The purpose of this study was to apply the microgenetic analysis method for development of information on an individual's change in a certain area during a consistent time period to seek change in scientific questions that elementary school students create. The study subjects were six 6th graders in I elementary school located in Kyunggido with the students conducting 6 sessions of two observational tasks about dry grapes contained in soda pop and candlelight. Information were collected through students' scientific question development paper, record of field observation and interviews. The results of this study are as follows: first, the number of scientific questions that the elementary school students developed showed a tendency for reduction; second, the changes in type of scientific questions bring different results, which depend on a particular characteristic of the tasks; third, By observing pattern changes in scientific questions of each individual, it was found that different results show for each time for the same task, which in other words means that there exists variability within an individual. Also, variability between individuals were shown by confirming that the change pattern for each person were diverse. Thus, the result of this study shows the following implications on education of scientific question development. For students, scientific question development mean more opportunities to increase the process of developing and acquiring knowledge. Therefore, it is important to create situations where one can come up with scientific questions. In addition, analysis in tasks' nature when selecting tasks would be necessary to develop diverse scientific questions.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.765-776
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• 2018

Artificial Intelligence is a rapidly growing technology with the latest developments in computing technology and is considered as one of the next major technologies. Chat-Bot is a system that is designed to respond to user's input according to the rules that are set up in advance and it provides more services through simple and repetitive tasks such as counseling, ordering and others. Accordingly, the study aims to present a model of a celeb-bot using Artificial Intelligence. Celeb-Bot is a combination of Celeb, which are short for Celebrity and Chat-bot. Celeb-Bot provides a Chat-Bot service that allows people to talk to a celebrity. The celeb is the best thing to build a relationship and has the advantages of being accessible to anyone. At the same time, Artificial Intelligence is a technology that can be seen as a person, not a product. Based on this, we believe that Celeb's Characteristic and Chat-bot based on artificial intelligence technologies need to be combined, so variety of products can generate synergy. It is predicted that there will be variety of derivatives that utilize this technology, and it is going to present a celeb-bot model accordingly.