• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.132-151
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• 2022

Vehicle localization is one of the core technologies for autonomous driving. Image-based localization provides location information efficiently, and various related studies have been conducted. However, the image-based localization methods using feature points or lane information has a limitation that positioning accuracy may be greatly affected by road and driving environments. In this study, we propose a line segment matching framework for accurate vehicle localization. The proposed framework consists of four steps: line segment extraction, merging, overlap area detection, and MSLD-based segment matching. The proposed framework stably performed line segment matching at a sufficient level for vehicle positioning regardless of vehicle speed, driving method, and surrounding environment.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.85-95
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• 2009

In the binaural synthesis environments, wide varieties of the head-related transfer functions (HRTFs) that have measured with a various direction would be desirable to obtain the accurate and various spatial sound images. To reduce the size' of HRTFs, interpolation has been often employed, where the HRTF for any direction is obtained by a limited number of the representative HRTFs. In this paper, we study on the distortion measures for interpolation, which has an important role in interpolation. With lhe various objective distortion metrics, the differences between the interpolated and the measured HRTFs were computed. These were then compared and analyzed with the results from the listening tests. From the results, the objective distortion measures were selected, that reflected the perceptual differences in spatial sound image. This measure was employed in a practical interpolation technique. We applied the proposed method to four kinds of an HRTF set, measured from three human heads and one mannequin. As a result, the Mel-frequency cepstral distortion was shown to be a good predictor for the differences in spatial sound location, when three HRTF measured from human, and the time-domain signal to distortion ratio revealed good prediction results for the entire four HRTF sets.

• Journal of the Korean Geographical Society
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• v.31 no.1
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• pp.49-67
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• 1996

On of Revolutionary changes of the commercial facilities is appearance of supermarket since the 1970's. It means modernization of retail establishment size. Simultaneously, and then path of distribution resulted in change. Namely, function of wholesale and retail is mixed, path of distribution is shortened, and then distribution function become more influential. By these changes, producer, manager and consumer can be benefit. That is, a change of commercial part is accurance to change of society and economy of region. The aim of the study is to examine commercial properties of supermarket in Kwangju city, and then, it is concerned with life of residents. Factor analysis is applied to the study. The results are as follows: Four factors are abstracted. The first factor of large explanation on properties of supermarket is accounted for years of management, land lent, number of establishments of wholesale${\cdot>$retail${\cdot>$service, age of manager, distance of neighbour residence, and so on. Namely, these may be regarded as commercial environmental feature. Moreover, regional distribution on the ground of factor score is concentrated on CBD and it's neighbour area, which are the areas of highest land lent in Kwangju city. The second factor is accounted for number of supermarket and number of population in each 'dong' (smallest factor-scored area is new housing complex in an outer ring of Kwangju. The third factor is accounted for number of workers, and size of establishment. Regional distribution is concentrated on neighbour of CBD and the outer ring area. These are scattered in contrast to the first and second factors which are continuous. The fourth factor is noted on a sale price of non-foodstuffs, that is, a feature of formation of goods. The highest factor score areas are the CBD, neighbour area of the CBD and a part of an outer ring area. On the other hand, the property of supermarket is preferred to 'the near distance' according to consumer's viewpoint. Furthermore, the location of supermarket, which is actually used by residents, is almost near residental area. It means that condition of location of supermarket is important in the distance of neighbour residence. Besides, supermarkets in Kwangju city are actually situated at residental area, that is, those locations in Kwangju city correspond to preference of consumer's viewpoint. Moreover, this result corresponds to the first factor of the analysis. Namely, the distance of property of supermarket from neighbour residence has very important effect on both of consumer and manager. In the end, supermarket is strongly related to life of residents. It means that supermarket is also responsible to quality of life. On the other hand, commercial facilities have been changed according to consumer's needs and social environments. For these reasons, commercial properties of supermarket must be reexamined in according to diverse commercial facilities and change of commercial environments.

• The Journal of the Acoustical Society of Korea
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• v.36 no.5
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• pp.345-352
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• 2017

We propose a methods which is reducing direction estimation error of sound source in the reverberant and noisy environments. The proposed algorithm divides speech signal into voice and unvoice using VAD. We estimate the direction of source when current frame is voiced. TDOA (Time-Difference of Arrival) between microphone array using the GCC-PHAT (Generalized Cross Correlation with Phase Transform) method will be estimated in that frame. Then, we compare the peak value of cross-correlation of two signals applied to estimated time-delay with other time-delay in time-table in order to improve the accuracy of source location. If the angle of current frame is far different from before and after frame in successive voiced frame, the angle of current frame is replaced with mean value of the estimated angle in before and after frames.

• The Journal of the Acoustical Society of Korea
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• v.8 no.4
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• pp.29-38
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• 1989

Detection of an underwater target by acoustic wave raises various difficulties due to unpredictable noise interference which originates from clutter, reverberation, and variations of medium characteristics with time and location. The SNR and the range resolution of conventional SONAR systems using a matched filter are generally poor, since the latter is optimum only in the additive white noise case. Furthermore, it cannot compensate for variations of the detection level which are responsible for the resultant detection errors. In this paper, the unpredictable interferences are compensated for by using an adaptive filter. It recursively estimates the channel impulse response based on the received echo signal. In the low noise environments, the estimated impulse response is close to the true one, providing a good range resolution, and a matched filter is used subsequently for the purpose of detection. It is shown through computer simulation that good performance can be achieved via the two steps of filtering. Also, the detection level remains unchanged without any additional provisions. Finally, we present the characteristics of the employed adaptive filter parameters.

• Earthquakes and Structures
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• v.18 no.4
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• pp.423-435
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• 2020

An accurate evaluation of structural damage is essential to performance-based seismic design for the structure across the earth fissure. By comparing the calculation results from three commonly used damage models and the experimental results, a weighted combination method using Chen model was selected in this paper as the seismic damage evaluation. A numerical model considering the soil-structure interaction (SSI) was proposed using ABAQUS software. The model was calibrated by comparing with the experimental results. The results from the analysis indicated that, for the structure across the earth fissure, the existence of earth fissure changed the damage distribution of the structural members. The damage of structural members in the hanging wall was greater than that in the foot wall. Besides, the earth fissure enlarged the damage degree of the structural members at the same location and changed the position of the weak story. Moreover, the damage degree of the structure across the earth fissure was greater than that of the structure without the earth fissure under the same excitation. It is expected that the results from this research would enhance the understanding of the performance-based seismic design for the structure across the earth fissure.

• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.173-177
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• 1986

This study was carried out to see what makes the 'dark grey cutworm', Agrotis tokionis Butler, inflict less damage in P.E. film-mulched tobacco fields than in nonmulched ones. In field plot experiment, the damage ratio of tobacco seed lings in mulched plots(m) was reduced by 63% compared with that in non mulched ones(n). The altered environments did not affect the cutworm in mortality, which was confirmed by recovery ratio, location of larvae in soil, and developmental age. But the m/n value and damage ratio in plots of different mulching methods strongly suggest that the P.E. film itself prevent larvae from cutting the plants. Larval mortality was rapidly increased between the end of July and the end of August.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.26-37
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• 2009

This paper suggests a sensor's placement method for detecting the dilemma zone problem when real-time driver's safety service is provided at signalized intersections by multiple pointed traffic sensors using USN environments. For detecting the dangerous situations from vehicles accelerating through yellow intervals, red-light running and stopping abruptly like as dilemma zone problem, VISSIM(microscopic, behavior-based multi-purpose traffic simulation program) is used to perform a real-time multiple detection situation by changing the input data like as various inflow-volume, design speed change, driver perception and response time. As a result, the optimal interval of traffic sensors is 20~27m, and the initialized sensor location from stop-line is different according to road design speed. Moreover, the pattern of detection about dilemma zone is also different according to inflow-volumes. This paper shows that the method is useful to evaluate the sensor's placement problem based on micro-simulation and the results can be used as the basic research for USN services.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.1
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• pp.41-59
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• 2022

Does the industrial complex of Korea leading the growth in manufacturing industry play the role of intensifying agglomeration effects? To answer this question, this study empirically analyzes the moderating effects of industrial complex on the relation between agglomeration externalities and regional productivity, which has not been covered by previous researches. To do so, analysis of panel data has been conducted using the regional level data for the period of 2010 to 2019. Empirical results are provided at different levels including the whole country, capital region and non-capital region. As a result, it was found that in non-capital region, environments to strengthen positive agglomeration externalities stemming from specialization and diversity in manufacturing through industrial complex whithin the region are built up. However, moderating effects of industrial complex is quite limited in capital region. This implies that the role of industrial complex needs to be importantly reconsidered in the perspective of maximization of agglomeration effects in manufacturing, revitalization of non-capital area and manufacturing innovation.

• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.7-14
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• 2011

Power analysis attack on low-power consumed security devices such as smart cards is very powerful, but it is required that the correlation between the measured power signal and the mid-term estimated signal should be consistent in a time instant while running encryption algorithm. The power signals measured from the security device applying the random clock do not match the timing point of analysis, therefore random clock is used as counter measures against power analysis attacks. This paper propose a new constant pitch based time alignment for power analysis with random clock power trace. The proposed method neutralize the effects of random clock used to counter measure by aligning the irregular power signals with the time location and size using the constant pitch. Finally, we apply the proposed one to AES algorithm within randomly clocked environments to evaluate our method.