• Annals of Clinical Neurophysiology
• /
• v.1 no.1
• /
• pp.26-30
• /
• 1999

Background : The origin of P300 was still on debate nbut thought to be in the frontal, temporal or parietal lobe. As the transcranial doppler ultrasonography(TCD) gives us and opportunity to observe hemodynamic chaged dynamically and the middle cerebral artery feeds these ares of the hemisphere, we observed the change of mean flow velocity of MCA during the event related potential test(ERP) to determine the role of these structures in P300 generation. Method : Twenty normal subjects(male : 13, age : 24-29 years) performed ERP. An auditory oddball pardigm was used to elicit the ERPs. TCD examination was performed with 2-MHz probe monitoring the left MCA(Transscan, EME). After signal identification and adjustments to maximize the Doppler signal strength, the probe was mechanically locked during the monitoring. The changes of blood flow velocity of the left middle cerebral artery(MCA) induced by cognitive demands were monitored. The measurement of the meal flow velocities(MFV) of MCA were made while the subjects were prior to, during, and after ERP. We recorded the MFVs during ERP. Statistical analysis was performed using t-tests with SPSS-PC for windows release 6.0. Results : All subjects showed a relative increase in MFV of MCA during the task. The mean rise was about 3.2-4.2%(p <0.05). Although TCD does not measure absolute values of regional cerebral blood flow(rCBF) or absolute rCBF changes, changes of flow velocity can reflect relative rCBF changes. Conclusions : The generation site of P300 still remains unclear but the neocortical, thalamic and limbic region and temporal-parietal cortex have been proposed. The MCA supplies these anatomical structures. The Changes of flow veolocity of MCA during the ERP test suggest that the some part of the brain fed y the MCA activate of the temporal lobe or parietal lobes, we can deduce that some parts of brain fed by the MCA participate in the generation of P300.

• KIPS Transactions on Computer and Communication Systems
• /
• v.7 no.2
• /
• pp.49-58
• /
• 2018

A certificate is a means to certify users by conducting the identification of the users, the prevention of forgery and alteration, and non-repudiation. Most people use an accredited certificate when they perform a task using online banking, and it is often used for the purpose of proving one's identity in issuing various certificates and making electronic payments in addition to online banking. At this time, the issued certificate exists in a file form on the disk, and it is possible to use the certificate issued in an existing device in a new device only if one copies it from the existing device. However, most certificate duplication methods are a method of duplication, entering an 8-16 digit verification code. This is inconvenient because one should enter the verification code and has a weakness that it is vulnerable to security issues. To solve this weakness, this study proposes a method for enhancing security certificate duplication in a multi-channel using TCP and BLE. The proposed method: 1) shares data can be mutually authenticated, using BLE Advertising data; and 2) encrypts the certificate with a symmetric key algorithm and delivers it after the certification of the device through an ECC-based electronic signature algorithm. As a result of the implementation of the proposed method in a mobile environment, it could defend against sniffing attacks, the area of security vulnerabilities in the existing methods and it was proven that it could increase security strength about $10^{41}$ times in an attempt of decoding through the method of substitution of brute force attack existing method.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.8
• /
• pp.37-43
• /
• 2018

A developer solves problems with isolating failures if faults are detected when inspecting missiles using the missile assembly test set (MATS) and then resumes the testing. In order to identify faults, it is necessary to analyze the data coming from the equipment, but the information received may not be sufficient, depending on the inspection environment. In this case, the developer repeats the test until the problem is reproduced or checks the performance of each piece of equipment that is related to the fault. When this task is added, schedule management becomes problematic, and development costs rise. To solve this problem, we need to design a MATS in a systematic way to increase fault coverage while satisfying the required reliability. By designing the necessary processes for each procedure, it is possible to reduce the fault identification time when a fault is detected during operations. But it is not possible to guarantee 100% fault coverage, so we provide another method by comparing costs and effects. This paper describes a development method to enhance the reliability of the missile assembly test set; it describes the expected effects when it is adapted, and describes the limitations of this method.

• Journal of The Korean Association For Science Education
• /
• v.35 no.4
• /
• pp.691-707
• /
• 2015

This study aims to develop biology teachers' education program based on argumentation activity about core concepts of evolution and to analyze the characteristics of core concepts of evolution learned during the program. The eight core concepts of evolution in this study were variation, heritability of variation, competition, natural selection, adaptation, differential reproductive rate of individuals, changes in genetic pool within a population, and macroevolution. The performances of teachers participating in the program were compared before and after argumentation activities; consisting of seven sessions on the eight core concepts of evolution. The process of the program was specially designed by learning cycle model for teacher education, consisting of seven phases: identification of the task, production of a tentative argument, small group's written argument, share arguments with the other groups, reflective discussion, final written argument, and organization by an instructor. Participants in the study were two pre-service biology teachers and four in-service biology teachers. The results suggest that biology teachers reduced the teleological explanation for biological evolution and improve its adequacy after the intervention. Teachers lacked the opportunity to discuss variation, heritability of variation, competition, and macroevolution because science textbooks lack information on the concepts of biological evolution. The results of this study suggest that because the argumentation program developed for teachers helps to improve understanding the concepts of evolution and to reduce inadequate conceptions in biology, teacher education programs using argumentation activity and eight core concepts of evolution will play a role for efficient evolution education for biology teachers.

• Korean Journal of Cognitive Science
• /
• v.24 no.4
• /
• pp.365-391
• /
• 2013

Negative repetition effect (NRE) refers to the phenomenon that the accuracy of report is impaired when a target was flanked by the same distractor than when by alternative distractor. To probe the nature of NRE, this study introduced attention window(s) indicating the positions where a target might be presented, and non-attention window(s) where a target could not be presented. Attention windows are supposed to help participants detect targets readily. Two among three positions are indicated by attention windows in Exp. 1, and a single large attention window encompassing central two positions among four positions was used in Exp. 2, and either large or small attention window was used depending on the number of target candidates in Exp. 3. In the result of three experiments, NREs were consistently observed when both positions of a target and a distractor were indicated by previous attention windows. However, NREs (including its tendency) and its opposite, PREs were observed when a distractor was presented in the non-attention position, depending on its distance from the target and the size of attention window. It seems that this pattern of repetition effects is hard to be explained by repetition blindness hypothesis (Kanwisher, 1991), positional uncertainty hypothesis (Keren & Boer, 1985), and inhibitory attention capture hypothesis (Kwak et al., 1993). Instead it was proposed that shifting of spatial attention should be considered accordingly with the structure of stimulus display. The promising role of this task was discussed in studying the relation of attention and perception.

• Land and Housing Review
• /
• v.2 no.3
• /
• pp.249-258
• /
• 2011

In order to achieve an efficient urban regeneration of the nation, it is required to determine the extent of decline nation-wide and the declined areas for each district and also to evaluate the potentials of the concerned areas. For this task to be accomplished, a construction of a comprehensive diagnostic system based on spatial information considering diversity and complexity is required. In this study, a total information system architecture for urban regeneration is designed as part of the construction of such a diagnostic system. In order to develop the system, a city and district level unit decline diagnostic indicators has been constructed and a decline diagnostic system has been developed. Also, a scheme to promote the advancement of the system is proposed. The DB construction is based on the city and district level nation-wide and metadata for the concerned level is constructed as well. The system is based on the Open API and designed to be flexible for extension. Also, an RIA-based intuitive UI has been implemented. Main features of the system consist of the management of the indicators, diagnostic analysis (city and district level decline diagnosis), related information, etc. As for methods for the advancement, an information model in consideration of the spation relations of the urban regeneration DB has been designed and application methods of semantic webs. Also, for improvement methods for district unit analytical model, district level analysis models, GIS based spatial analysis platforms and linked utiliation of KOPSS analysis modules are suggested. A use of a total information system for urban regeneration is anticipated to facilitate concerned policy making through the identification of the status of city declines to identify and the understanding of the demands for regeneration.

• Korean Journal of Veterinary Service
• /
• v.40 no.3
• /
• pp.201-208
• /
• 2017

BVDV causes significant infections in ruminants, resulting in reproductive disorders, diarrhea, reduced milk production and enormous damage to farms. In particular, identification and culling of persistent infectious calf is an important task to eliminate infectious nidus in cattle households. However, studies on physiological characteristics of PI bull are still insufficient to understand reproductive effects of BVDV. In this study, one PI bull was confirmed in herd and complete blood analysis was performed. The lymphocyte count of PI at age 4 was below the normal range and the number of WBCs was also in the lower level of normal range in blood. The sperm number produced by PI male becomes lower and the viability of fresh sperm comes to poor with ages (P<0.05). The sperm abnormality was also increased, especially in nuclear vacuoles of head and droplets of midpeace (P<0.05). The PI male becomes infertile due to poor semen quality at age 4. With these results, we concluded that BVDV in PI bull cause decreased sperm cell and abnormality in semen so causes infertility. However, it appears that BVDV could not be transmitted by indirect contact of PI bull, because there was no evidence of BVDV infection in the herd, when regular vaccination program was applied.

• Journal of Internet Computing and Services
• /
• v.17 no.3
• /
• pp.87-93
• /
• 2016

In the current information-based society, information and communication technology(ICT) is very important for an individual, a society, and a nation. Especially, for a nation, ICT-related industries are forming an important part of a nation's economy. Also, unlike other industries, ICT-related industries do not require various infrastructures, and have an advantage of being developed with a few talented persons in a short period of time. In this sense, identification and education of gifted children in IT become an essential task of a nation's future. In the past, selection of the gifted children was based on paper tests. However, paper tests incurred various side effects such as private education. Since 2013, observation-recommendation system instead of paper tests has been fully adopted. The purpose of this paper is to analyze the validity of observation-recommendation admission system of the gifted children in IT. For this research purpose, the gifted children in gifted science education center attached in a university at Seoul become the focus of the samples. Their entrance score ranking and graduation record raking are compared for analysis of validity of admission system. After statistical analysis, there is a meaningful correlation between entrance score ranking and graduation record ranking for the gifted children in IT. It means that the higher entrance score ranking, the higher graduation record ranking. The analysis results are expected to be valuable baseline data for deciding usefulness of observation-recommendation admission system.

• Journal of Construction Engineering and Project Management
• /
• v.5 no.2
• /
• pp.11-15
• /
• 2015

The Last PlannerSystem (LPS) has been implemented on construction projects to increase work flow reliability, a precondition for project performance againstproductivity and progress targets. The LPS encompasses four tiers of planning processes:master scheduling, phase scheduling, lookahead planning, and commitment / weeklywork planning. This research highlights deficiencies in the current implementation of LPS including poor lookahead planning which results in poor linkage between weeklywork plans and the master schedule. This poor linkage undetermines the ability of theweekly work planning process to select for execution tasks that are critical to projectsuccess. As a result, percent plan complete (PPC) becomes a weak indicator of project progress. The purpose of this research is to improve lookahead planning (the bridgebetween weekly work planning and master scheduling), improve PPC, and improve theselection of tasks that are critical to project success by increasing the link betweenShould, Can, Will, and Did (components of the LPS), thereby rendering PPC a betterindicator of project progress. The research employs the case study research method to describe deficiencies inthe current implementation of the LPS and suggest guidelines for a better application ofLPS in general and lookahead planning in particular. It then introduces an analyticalsimulation model to analyze the lookahead planning process. This is done by examining the impact on PPC of increasing two lookahead planning performance metrics: tasksanticipated (TA) and tasks made ready (TMR). Finally, the research investigates theimportance of the lookahead planning functions: identification and removal ofconstraints, task breakdown, and operations design.The research findings confirm the positive impact of improving lookaheadplanning (i.e., TA and TMR) on PPC. It also recognizes the need to perform lookaheadplanning differently for three types of work involving different levels of uncertainty:stable work, medium uncertainty work, and highly emergent work.The research confirms the LPS rules for practice and specifically the need to planin greater detail as time gets closer to performing the work. It highlights the role of LPSas a production system that incorporates deliberate planning (predetermined andoptimized) and situated planning (flexible and adaptive). Finally, the research presents recommendations for production planningimprovements in three areas: process related, (suggesting guidelines for practice),technical, (highlighting issues with current software programs and advocating theinclusion of collaborative planning capability), and organizational improvements(suggesting transitional steps when applying the LPS).

• Journal of The Korean Association For Science Education
• /
• v.19 no.1
• /
• pp.146-158
• /
• 1999

Since 1960' s. aims of science education have changed from attainment of scientific concepts. principles and laws to improvement of science process(or inquiry) skills. According to the science education philosophy like this. our nation has adopted improvement and evaluation of science process(or inquiry) skills in science education. The purpose of this study was to examine the performance of high school students on 4 types of multiple choice items used to access students ability to identify independent and dependent variables. Stimulus materials were either a question focusing on the relationship between two variables. a hypothesis. a description of an experiment. or a description of results of an experiment. Student performance on these item types was compared to this performance on a standard Piagetian interview task of variable identification. The results of the study included: (1) the "hypothesis" type was the most difficult, while the "question" type appeared to be the easiest; (2) the "procedure" item type had a higher correlation with the total interview than any other item type. Among conclusions reached in this study was that although all four item types operated similarly. they did not correlate very highly with the performance assessment by interview.