• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.380-387
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• 2012

A complex seismic survey, which is nondestructive inspection, is used often recently in estimating the location of reclaimed cultural assets. Such a method is the best way to estimate the location of cultural assets most effectively in a short time at a construction site. This study estimated the reclamation location of a cultural asset by using magnetic gradient survey, earth resistivity survey, and ground penetrating radar survey (GPR) in order to figure out the distribution territory in the area with possibility of creation of reclaimed cultural assets in the past. As a result, it was located at +15m on the X axis and +90m on the Y axis on the floor plane coordinate of the study target area. It was shown that the major axis is about 20m long in the north-northeast direction and the width is about 5m. The depth of development distribution of anomaly zone was estimated as about 1.5~3.0m. Geophysical survey is expected to be used as a efficient and accurate way to excavate the reclaimed cultural assets in future.

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.95-102
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• 2006

In this paper, we model a traffic of multiple tags operated in 2.45GHz band RTLS environment and analyze the multi-tag interference. Also, we propose a high precision location estimation algorithm of RTLS and then analyze its performance. From the results, the BER performance of RTLS degrades as the number of multi-tags increase in Gaussian noise and fading(m=15) environment. To meet the BER specification of RTLS, $10^{-5}$, we have to limit the multi-tag number to below 40. We also estimate the tag's location in $250m{\times}250m$ searching-area with enhanced TDOA scheme. It is confirmed that the 3m radius within accuracy of RTLS specification is satisfied, if the number of sub-blink receives more than 2 when available reader is 3 to 8.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.1
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• pp.44-49
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• 2012

Introduction: Sialolithes are initiated by localized deposition of calcified material in the salivary glands. And that may even cause various symptom especially swelling and pain. This study purposes to collect statistical data of sialolithiasis for clinical analysis. Materials and Methods: Among forty seven patients who have visited Seoul National University Dental Hospital during 2004-2009, patients' age, sex, location and size of stone, radiodensity of stone, symptom, surgical procedure were investigated. Statistical correlation between size, location, symptom was evaluated. Chemical composition was analyzed for 3 sialolithes. Results: The average age was 41.4 years. Sialolithiasis had slight female predilection (57.4%). Most cases occurred in the submandibular glands (91.5%). And most cases had radiopaque features (95.8%). The average size was 7.17 mm. The most frequent location of the stones were the duct orifice and the submandibular gland hilum (16 cases in each), followed by the middle part of the duct (n=8), the intraglandular area (n=4), and the proximal part of the duct (n=3). Eleven cases were asymptomatic. Thirty six cases had complaints of pain, swelling, hardness, and decrease in saliva flow (multiple symptoms). Various methods of surgery was performed. Two cases were self-removed. Thirty seven cases underwent procedure involving stone removal alone. Six cases underwent gland extirpation, and two cases underwent ductoplasty. Conclusion: There was no statistical correlation between size, location, and symptoms. Sialolith was composed of Ca (58.5-69.3%), P (30.7-35.7%), organic material, and trace inorganic material.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.161-172
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• 2017

In the paper, a hybrid technique is proposed for detecting the location and capacity of distributed generation (DG) sources like wind and photovoltaic (PV) in power system. The novelty of the proposed method is the combined performance of both the Biography Based Optimization (BBO) and Particle Swarm Optimization (PSO) techniques. The mentioned techniques are the optimization techniques, which are used for optimizing the optimum location and capacity of the DG sources for radial distribution network. Initially, the Artificial Neural Network (ANN) is applied to obtain the available capacity of DG sources like wind and PV for 24 hours. The BBO algorithm requires radial distribution network voltage, real and power loss for determining the optimum location and capacity of the DG. Here, the BBO input parameters are classified into sub parameters and allowed as the PSO algorithm optimization process. The PSO synthesis the problem and develops the sub solution with the help of sub parameters. The BBO migration and mutation process is applied for the sub solution of PSO for identifying the optimum location and capacity of DG. For the analysis of the proposed method, the test case is considered. The IEEE standard bench mark 33 bus system is utilized for analyzing the effectiveness of the proposed method. Then the proposed technique is implemented in the MATLAB/simulink platform and the effectiveness is analyzed by comparing it with the BBO and PSO techniques. The comparison results demonstrate the superiority of the proposed approach and confirm its potential to solve the problem.

• Journal of the Korean Geographical Society
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• v.43 no.2
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• pp.220-234
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• 2008

In many security monitoring contexts, the performance or efficiency of surveillance sensors/networks based on a single sensor type may be limited by environmental conditions, like illumination change. It is well known that different modes of sensors can be complementary, compensating for failures or limitations of individual sensor types. From a location analysis and modeling perspective, a challenge is how to locate different modes of sensors to support security monitoring. A coverage-based optimization model is proposed as a way to simultaneously site k different sensor types. This model considers common coverage among different sensor types as well as overlapping coverage for individual sensor types. The developed model is used to site sensors in an urban area. Computational results show that common and overlapping coverage can be modeled simultaneously, and a rich set of solutions exists reflecting the tradeoff between common and overlapping coverage.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1113-1120
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• 2013

A numerical analysis of the effect of the position of a circular cylinder in a $45^{\circ}$ tilted enclosure on natural convection in the enclosure is presented. The location of the cylinder is changed between -0.4 and 0.4. The Rayleigh number is varied between $10^3$ and $10^5$. The effect of the location of the cylinder on natural convection in the enclosure is analyzed by the isothermal line, stream line, and surface-averaged Nusselt number. The flow and heat transfer characteristics are independent of time in the range of the Rayleigh number and cylinder location that is considered in this study. The surface-averaged Nusselt number of the cylinder and enclosure increases as the cylinder gets closer to the wall of the enclosure.

• Journal of Korea Spatial Information System Society
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• v.11 no.1
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• pp.115-126
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• 2009

Recent development in wireless communication and mobile positioning technologies makes Location-Based Services (LBSs) popular. However, because, in the LBSs, users request a query to database servers by using their exact locations, the location information of the users can be misused by adversaries. Therefore, a mechanism for users' privacy protection is required for the safe use of LBSs by mobile users. For this, we, in this paper, propose a efficient cloaking region creation scheme using Hilbert curves in distributed grid environment, so as to protect users' privacy in LBSs. The proposed scheme generates a minimum cloaking region by analyzing the characteristic of a Hilbert curve and computing the Hilbert curve values of neighboring cells based on it, so that we may create a cloaking region to satisfy K-anonymity. In addition, to reduce network communication cost, we make use of a distributed hash table structure, called Chord. Finally, we show from our performance analysis that the proposed scheme outperforms the existing grid-based cloaking method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.3
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• pp.303-309
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• 2011

Situation awareness services which increasingly expand their influence in everyday life can be classified into location-based service and social network service. Their quality of service (QoS) can be differed based on the location accuracy of smart phones and accuracy of directional recognition technology. This study was conducted to analyze GPS, digital compass, radio communication, and geospatial web information which can provide a clue in using the situation aware services based on lab experiments and surveys. According to the result of lab experiment on accuracy of determining location / direction with smart phones, owing to inherent lack of indoor accuracy in determining position and direction, as well as errors in spatial data used as platform, it was found that devices were not provided with sufficiently accurate data when using the situation aware services indoors compared to outdoors. To enhance accuracy of determining indoor positions, there are several methods including location metering based on Wi-Fi, which had several problems compared with GPS used in outdoor environment. Thus, it was determined that more study would be necessary to solve these issues.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.1
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• pp.73-80
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• 2000

To determine the exact direction and location of the human joint in motion is crucial in developing a more accurate human model and producing a more fitting artificial joint. There have been several reports on the biomechanical analysis of the joint to determine the anatomy and movement of joints. However, all the previous researches were made in vitro study, that is, they investigated the passive movement of the joint from cadavers and the suggested location of the joint axis was difficult to make practical applications due to the lack of the direction of joint axis. Also, in many biomechanical models, each joint axis is assumed to lie horizontally or vertically to the adjacent links. Such an assumption causes inherent inaccuracy. In this study, the direction and location of the transverse elbow axis was obtained with respect to the global coordinate system whose origin is on the lateral epicondyle of the humerus. The suggested result based on the global coordinate system lying on the external landmark will be helpful to understand the information of the axis and to make an application. From the experiments conducted for five subjects, the direction and location of the elbow transverse joint was determined for each subject by the helical axis method. A statistical validation was also performed to confirm the result. Finally, the result was applied to develop a simple elbow model which is a part of the kinematic arm model. The simple elbow movement model was developed to validate the significance of the result and the kinematic arm model was able to describe the geometry of any complex linkage system. As a result, the errors incurred from the proposed model were significantly reduced when compared to the ones from the previous approach.

• Clinics in Shoulder and Elbow
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• v.19 no.4
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• pp.202-208
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• 2016

Background: Our study aimed to make a comparative analysis of clinical outcomes of arthroscopic decompression for rotator cuff calcific tendinitis by location of calcific deposits and by its size. Methods: We enrolled a total of 38 patients, comprising 39 affected shoulders, who underwent arthroscopic decompression for calcific tendinitis. As our clinical scores, we evaluated the UCLA, the ASES, and the VAS scores and analyzed them by calcific location, by calcific deposit size, by the presence or absence of calcific remnants, and by whether concomitant cuff repair was performed. Results: The clinical scores of those whose calcific deposit had an area greater than $77.0mm^2$ and of those whose calcific deposit had an area smaller than $77.0mm^2$ did not significantly differ (p=0.21 in ASES; p=0.19 in UCLA; p=0.17 in VAS). Nor did the clinical scores significantly differ with respect to the location of calcification (p=0.23). Further, the clinical scores did not significantly differ between those who had calcific remnants and those who did not and between those who received additional cuff repair and those who did not. Conclusions: We found that the clinical outcomes after arthroscopic decompression of calcific tendinitis were not significantly associated with the cuff tendon in which the calcium deposits are found; the location of the calcium deposits in the supraspinatus tendon (if found in this tendon); the size of calcific deposits; the presence of calcific remnants; and concomitant cuff repairs.