• Journal of The Korean Association For Science Education
• /
• v.41 no.5
• /
• pp.371-390
• /
• 2021

The purpose of this study is to develop a neuropsychological model for the spatial ability factor and to divide the brain active area involved in the light & shadow problem solving process into the domain-general ability and the domain-specific ability based on the neuropsychological model. Twenty-four male college students participated in the study to measure the synchronized eye movement and electroencephalograms (EEG) while they performed the spatial ability test and the light & shadow tasks. Neuropsychological model for the spatial ability factor and light & shadow problem solving process was developed by integrating the measurements of the participants' eye movements, brain activity areas, and the interview findings regarding their thoughts and strategies. The results of this study are as follows; first, the spatial visualization and mental rotation factors mainly required activation of the parietal lobe, and the spatial orientation factor required activation of the frontal lobe. Second, in the light & shadow problem solving process, participants use both their spatial ability as a domain-general thought, and the application of scientific principles as a domain-specific thought. The brain activity patterns resulting from a participants' inferring the shadow by parallel light source and inferring the shadow when the direction of the light changed were similar to the neuropsychological model for the spatial visualization factor. The brain activity pattern from inferring an object from its shadow by light from multiple directions was similar to the neuropsychological model for the spatial orientation factor. The brain activity pattern from inferring a shadow with a point source of light was similar to the neuropsychological model for the spatial visualization factor. In addition, when solving the light & shadow tasks, the brain's middle temporal gyrus, precentral gyrus, inferior frontal gyrus, middle frontal gyrus were additionally activated, which are responsible for deductive reasoning, working memory, and planning for action.

• The Korean Journal of Ecology
• /
• v.6 no.1
• /
• pp.33-44
• /
• 1983

Vegetatiion structure and population dynamcis of pine needle gall midge were investigated from 1980 to 1982 at the southern part of Palgong mountain near Daegu. The results of investigation at the areas of A (pure stand), B(30% mixed forest) adn C(60% mixed forest) were as follow; Vegeation of 3 areas were not classified by the species diversity, but by the unequal distribution of Alnus hirsuta, Robinia pseudo-acacia, Lespedeza cyrtobotrya, Quercus variabilis and vitality of Pinus densiflora at the area C was low, due to shadow by broad-leaf trees. Soil environmental factors at 3 areas not characteristic, but the average of humus contents showed high significance and the order was A

• KDI Journal of Economic Policy
• /
• v.38 no.4
• /
• pp.95-114
• /
• 2016

We study how an advantage given to an interim winner in sequential conflicts characterizes dynamic competition between players and influences their payoffs. As the intensity of competition during each period is negatively correlated, perfect security is not necessarily desirable for contending parties. We present results which are widely applicable to various types of dynamic competition, where competition in each period is linked to the interim winner's relative advantage. Policy implications are also discussed in a variety of areas, and several extensions are explored.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.676-680
• /
• 1994

Recently the needs for the experts who can solve the complex problem arising at the special areas are continuously increasing in our social life. So many researchers have studied about the expert systems as a part of an artificial intelligence during last two decades. This study was carried out in order to develope an expert system, ESSM, for the NC data generation to machine the curved surface of a forming die to fabricate the shadow mask of TV Brown Tube.

• The Journal of the Korean dental association
• /
• v.5 no.1
• /
• pp.56-59
• /
• 1964

The authors have observed a case of giant-cell reparative granuloma which were occurred in the mandible of 30 year old man . 1.The lesion of accompanying inflammation was lacated at the anterior portion of the mandible. 2.Radiograph shows ovoid radiolucent shadow with irregular margin. 3. Microscopic section reveals granulation tissue and many multinucleated gaint cells exist adjacent to the hemorrhagic areas.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10b
• /
• pp.643-645
• /
• 2003

위성사진에서 그림자 영역을 추출하고 그 화질을 개선하는 것은 이 분야에서 생길 수 있는 다양한 응용 때문에 관심있는 연구분야로 떠오르고 있다. 이 논문은 한국의 위성사진에서 흔히 볼 수 있는 아파트와 같은 건물이 있는 도시의 화상에서 그림자 영역을 자동 추출하는 방법을 제안하고 있다. 제안된 알고리듬은 공간영역에서 히스토그램의 특성을 이용하고 주파수영역에서 고속푸리에변환과 코릴레이션을 이용한다. 실험결과는 이 방법이 효과적임을 보여준다.

• Journal of the Korean association of regional geographers
• /
• v.22 no.4
• /
• pp.887-911
• /
• 2016

The empirical law that transverse dunes migrate inversely with their heights leads logically to the prediction that multiple dune ridges will converse to a single huge dune by merging. This contradicts the existence of the steady state dune fields on the Earth. The recent studies have emphasized dune collisions as a key mechanism to the stability of dunefield. The roles of wind shadow aspect ratio, however, have yet to be fully explored. This research aims to investigate the potential roles of wind shadow aspect ratio in the dynamical behaviors of transverse dune field. The simplified model is established for this, based upon allometric properties of transverse dunes, wind speedup on the stoss slope and sand trapping efficiency. The derived governing equations can be transformed to the zoning criteria and vector field for dune evolution. The dynamics analysis indicates that wind shadow aspect ratios do not produce convergent areas on the behavior space; rather, they just act as one of the factors that affect the trajectories of dune evolution. Though the model cannot represent the stability of dune field, but seem to produce a reasonable exponent for dune spacing-height relations.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.10
• /
• pp.2195-2202
• /
• 2011

Recently, navigation system is used to inform users of vehicle location and driving direction, moving distance and so on. This navigation uses GPS sensor for current location determination. The GPS sensor will determinate current coordinates by using triangulation algorithm. This characteristic bring about that the GPS signal is not available in the shadow region such as tunnel and urban canyon. Moreover, Even though the signal is available, inherent positional error rate of the GPS often results in the dislocation of vehicle. To solve, these problems, a new positioning system is proposed in the paper. The System utilizes geomagnetic sensors of smartphone, speed information of CAN of vehicle though bluetooth and WiFi APs for GPS shadow area. The experimental test shadows that the proposed system using multiple data is able to determine the position of vehicle in GPS shadow areas.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.10
• /
• pp.2059-2064
• /
• 2011

The DGPS systems that is a GPS augmentation system were installed for ocean- and land-service. The ocean-based reference station of 11 site and the land-based reference station of 6 sites are operating for ocean- and land-service. Although the land-based reference stations provide the output power of 500W, the service shadow regions are occurred due to mountain lands and building area. In this paper, the service coverages for land-based reference stations are analyzed in conditions of output power enhancements of reference station. The service shadow areas are deduced from service coverages of land-based reference stations and ocean-based reference stations. The medium frequency-band wave propagation models are considered as DGPS wave propagation model. The service coverages are analyzed by considering the compensated ground surface-conductivity.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.8A
• /
• pp.838-845
• /
• 2008

In this study, we developed a OBE(On Board Equipment) system in which moving cars communicate directly each other to exchange traffic information. this system achieved by using DSRC(Dedicated Short Range Communication). this technology can improve the fidelity of collected information by transferring current state information from a moving car to center in real time. As a consequence of it, moving cars can be offer information service of hight quality even in a shadow zone. and also, in addition to basic ETC function for toll payment, using our newly developed system, delivering traffic information and providing additive service like GPS can be achieved by car-to-car direct communication within shadow areas without additional infra-structure.