• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.461-462
• /
• 2019

본 논문은 실제 차량 운행 조건에서 차량에 적용한 태양광 발전모듈의 발전특성을 분석하였다. 태양광 발전모듈 적용차량의 발전특성 분석을 위해 조도계 및 온도계를 이용한 실제 데이터를 활용하였으며, 차량 조건 및 온도 조건에 따라 발전 가능한 최대전력량을 도출하였다. 태양광 발전모듈에 대한 특성 데이터 및 태양광 발전모듈 적용차량의 실제 도로 운행 시 측정된 일사량 데이터를 통하여 태양광 발전모듈을 탑재한 차량의 발전특성을 연구하였다.

• Proceedings of the Korean Society for Information Management Conference
• /
• 2016.08a
• /
• pp.57-60
• /
• 2016

2015년부터 우편번호를 대체하는 국가기초구역번호를 기반으로, 기존 읍면동 구분을 국가기초구역으로 대체하여 도서관에서 지역분포 분석 서비스를 제공하는 방안을 모색하였다. 기존에 제공하던 법정동 기준의 지역 구분은 균일한 크기의 지역 구분이 쉽지 않아 이를 행정동 기준으로 전환하고, 이 경계를 바탕으로 국가기초구역에 최대한 일치하도록 구역을 설정하여 기존 읍면동 체제와 크게 어긋나지 않으면서 새로운 국가기초구역제도를 조기에 활용할 수 있도록 하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2020.11a
• /
• pp.98-99
• /
• 2020

최근 다양한 응용 분야에서 딥러닝을 적용한 사례가 나오고 있으며, 딥러닝 네트워크 경량화 또는 압축 기법을 적용해 정확도는 최대한 유지하면서 에너지 효율을 개선하려는 연구도 활발하게 이루어지고 있다. 이에 본 논문에서는 딥러닝 추론 과정에서 중간 데이터로 도출되는 활성화 데이터의 압축을 위해 연속 길이 부호화 방법을 적용해보고 압축률과 개선점에 대해 분석 한다.

• Journal of Astronomy and Space Sciences
• /
• v.20 no.4
• /
• pp.283-298
• /
• 2003

The 2001 Leonid meteor storm has been observed all over the world, and its most intense flux since the last few decades has caused great interest among both laymen and experts. Especially, its maximum hours occurred at dawn hours of Nov. 19 in the east Asia, during which moonless clear night at the Mt. Bohyun allowed us near perfect condition of observation. Observation was carried out in the period of 01:00∼05:40(KST), which include the predicted maximum hours, with all-sky camera installed for upper atmospheric airglow research. Tn this paper we analyze 68 all-sky images obtained in this period, which contain records of 172 meteors. Utilizing the zenith hourly rate(ZHR) of 3000 and magnitude distribution index of 2, which were reported to International Meteor Organization by visible observers in the east Asia, we estimate the limiting magnitude of about 3 for meteors detected in our all-sky images. We then derive magnitudes of 83 meteors with clear pixel brightness outlines among the initially detected 172 meteors by comparing with neighbor standard stars. Angular velocities of meteors needed for computing their passing times over an all-sky image are expressed with a simple formula of an angle between a meteor head and the Leonid radiant point. The derived magnitudes of 83 meteors are in the range of -6∼-1 magnitude, and its distribution shows a maximum new -3mag. The derived magnitudes are much smaller than the limiting magnitude inferred from the comparison with the result of naked-eye observations. The difference may be due to the characteristic difference between nearly instantaneuous naked-eye observations and CCD observations with a long exposure. We redetermine magnitudes of the meteors by adjusting a meteor lasting time to be consistent with the naked-eye observations. The relative distribution of the redetermined magnitudes, which has a maximum at 0 mag., resembles that of the magnitudes determined with the in-principle method. The relative distribution is quite different from ones that decrease monotonically with decreasing magnitudes for meteors(1∼6) sensitive to naked-eye observations. We conclude from the magnitude distribution of our all-sky observation that meteors brighter than about 0 mag., appeared more frequently during the 2001 Leonid maximum hours. The frequent appearance of bright meteors has significantly important implication for meteor research. We noted, however, considerably large uncertainties in magnitudes determined only by comparing standard stars due to the unknown lasting time of meteors and the non-linear sensitivity of all-sky camera.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_1
• /
• pp.1211-1224
• /
• 2023

Clouds cause many difficult problems in observing land surface phenomena using optical satellites, such as national land observation, disaster response, and change detection. In addition, the presence of clouds affects not only the image processing stage but also the final data quality, so it is necessary to identify and remove them. Therefore, in this study, we developed a new cloud detection technique that automatically performs a series of processes to search and extract the pixels closest to the spectral pattern of clouds in satellite images, select the optimal threshold, and produce a cloud mask based on the threshold. The cloud detection technique largely consists of three steps. In the first step, the process of converting the Digital Number (DN) unit image into top-of-atmosphere reflectance units was performed. In the second step, preprocessing such as Hue-Value-Saturation (HSV) transformation, triangle thresholding, and maximum likelihood classification was applied using the top of the atmosphere reflectance image, and the threshold for generating the initial cloud mask was determined for each image. In the third post-processing step, the noise included in the initial cloud mask created was removed and the cloud boundaries and interior were improved. As experimental data for cloud detection, CAS500-1 L2G images acquired in the Korean Peninsula from April to November, which show the diversity of spatial and seasonal distribution of clouds, were used. To verify the performance of the proposed method, the results generated by a simple thresholding method were compared. As a result of the experiment, compared to the existing method, the proposed method was able to detect clouds more accurately by considering the radiometric characteristics of each image through the preprocessing process. In addition, the results showed that the influence of bright objects (panel roofs, concrete roads, sand, etc.) other than cloud objects was minimized. The proposed method showed more than 30% improved results(F1-score) compared to the existing method but showed limitations in certain images containing snow.

• Journal of Oral Medicine and Pain
• /
• v.31 no.4
• /
• pp.365-373
• /
• 2006

This study suggested correction of excessive mouth opening or maximum occlusal contact to analyse occlusal contact time, occlusal contact number and force through evaluation of occlusal pattern in policemen with temporomandibular disorders. The community of policemen influence on temporomandibular disorder's development and progress due to other condition of mouth opening and maximal occlusal contact. Repeated training or changes of usual life style may cause imbalance of stomatognathic system including the masticatory muscle, then develop or aggravate pain of temporomandibular joints and associated structures. This study uses T-scan II system(Tekscan Co., USA) for evaluation on occlusal pattern may influence temporomandibular disorders, and then the subjects take a sensor at 20 mm opening for maximal occlusal contact force. The policemen with temporomandibualr disorders get more long time on maximum contact timing, more short on end contact timing, and more force on end contact force than general society's. So they get closure of mouth with more short time and more force, then transfer remaining load to temporomandibular joint. There are no statistically significances between affected side and occlusal pattern of occlusal contact time and force. There are Left -right dental arch imbalances seems on Rt. dental arch if affected side is right and Lt. dental arch if affected side is left. In above results, It's worth due consideration that policemen with temporomandibular disorders get more smooth mandibualr movement and less force on maximal occlusal contact position.

• Journal of Wetlands Research
• /
• v.7 no.2
• /
• pp.121-132
• /
• 2005

To classify the surface sedimentary facies using IKONOS image collected over Hwangdo tidal flat in Cheonsu Bay, the optical reflectance was compared for characterizing various sedimentary environments such as grain size, tidal channel pattern and area ratio of surface remnant water. The intertidal DEM (Digital Elevation Model) was generated by echo-sounder for analyzing the relationship between IKONOS image and sedimentary environments including topography. The boundary of the optical reflectance between mud-mixed facies and sand facies was distinct, and discrimination of the associated sandbar feature was also possible. The mud-mixed facies coupled with intricate tidal channels is confined to the relatively hi호 topography of Hwangdo tidal flat. The boundary between mud and mixed flat was indistinct in IKONOS optical reflectance but it would have a difference in the area ratio of surface remnant water. The dark area in the image represented the well developed sand facies having a lot of surface remnant water due to the relatively low surface topography. The overall accuracy of characterizing the surface sediment facies by maximum likelihood classification method was 86.2 %. These results demonstrate that high spatial resolution satellite imagery such as IKONOS coupled with knowledge of grain size, surface remnant water and tidal channel network can be effectively used to characterize the surface sedimentary facies (mud, mixed and sand) network of the tidal flat environments.

• Journal of Oral Medicine and Pain
• /
• v.22 no.1
• /
• pp.111-123
• /
• 1997

Peroxidase system은 구강내 고유의 항균체계로서 항세균물질인 $HOSCN/OSCN^-$을 생산하여 다양한 그램 양성 그리고 그램 음성 세균에 대해 살균 및 정균작용을 나타낸다. 본 연구는 peroxidase system을 함유한 치약을 사용한 후 건강한 대상자의 자극성 전타액내 생성되는 $HOSCN/OSCN^-$의 양을 측정하여 최대 생성시간을 결정하였다. 그 후 건강한 대상자에게 임의로 실험치약과 대조치약을 할당하여 2주간 사용하도록 한 후 $HOSCN/OSCN^-$ 최대 생성 시간에 타액을 채취하여 치약 사용전과 2주후의 타액분비량, pH, 점조도 그리고 S. mutans와 lactobacilli에 대한 항균효과를 비교하였다. 구강건조증 환자를 대상으로 한 두 번째 연구에서도 peroxidase system을 함유한 세치제를 사용한 후 생성되는 $HOSCN/OSCN^-$의 최대생성시간을 측정하였으며, peroxidase system을 함유한 세치제가 S. mutans와 lactobacilli에 미치는 영향을 양치전과 양치후 $HOSCN/OSCN^-$의 최대생성시간에 타액을 채취하여 비교하였다. 이와같은 실험을 통해 다음과 같은 결론을 얻었다. 1. 건강한 대상자의 자극성 전타액내의 $HOSCN/OSCN^-$의 농도는 양치후 30분 후 대조군에 비해 peroxidase systems을 함유한 세치제를 사용한 군에서 유의성있게 높게 나타났다 (p < 0.05). 2. 건강한 대상자의 자극성 전타액의 타액분비량, pH, 타액점조도는 peroxidase system을 함유한 세치제를 2주간 사용한 후에도 유의한 변화를 나타내지 않았다. 3. 2주간 실험치약을 사용한 후 건강한 대상자의 자극성 전타액내 S. mutans와 lactobacilli의 양은 peroxidase system을 함유한 세치제를 사용한 군에서 상대적으로 낮게 나타났으나 통계학적 유의성은 없었다(p = 0.206 : lactobacilli, p = 0.944 : S. mutans). 4. 구강건조증 환자의 자극성 전타액내의 $HOSCN/OSCN^-$의 농도는 양치후 30분(p < 0.01)과 60분(p < 0.05)에서 대조군에 비해 peroxidase system을 함유한 세치제를 사용한 군에서 유의성있게 높았다. 5. 구강건조증 환자의 양치 후 30분에 채취한 자극성 전타액내의 S. mutans와 lactobacilli의 양은 peroxidase system을 함유하거나(p < 0.01) 함유하지 않은(p < 0.05) 치약을 사용한 군 모두에서 양치전에 비해 유의성있게 감소하였다. 6. 양치후 30분에 채취한 구강건조증 환자의 자극성 전타액내 S. mutans 양은 peroxida system을 함유한 세치제를 사용한 군에서 대조군에 비해 유의성있게 낮았다(p < 0.05). 7. 양치후 30분에 채취한 구강건조증 환자의 자극성 전타액내 lactobacilli양은 peroxidase system을 함유한 세치제를 사용한 군에서 대조군에 비해 상대적으로 낮게 나타났으나(p = 0.067) 통계학적 유의성은 없었다.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.5
• /
• pp.1077-1085
• /
• 2017

In this study, we have found the major factors which affect Korean women's wage analysing the data provided by 2015 Korea Labor Panel Survey (KLIPS). In general, wage data is difficult to analyze because random sampling is infeasible. Heckman sample selection model is the most widely used method for analysing the data with sample selection. Heckman proposed two kinds of selection models: the one is the model with maximum likelihood method and the other is the Heckman two stage model. Heckman two stage model is known to be robust to the normal assumption of bivariate error terms. Recently, Marchenko and Genton (2012) proposed the Heckman selectiont model which generalizes the Heckman two stage model and concluded that Heckman selection-t model is more robust to the error assumptions. Employing the two models, we carried out the analysis of the data and we compared those results.

• The Korean Journal of Applied Statistics
• /
• v.31 no.1
• /
• pp.109-122
• /
• 2018

The composite lognormal-generalized Pareto distribution (LN-GPD) is a mixture of right-truncated lognormal and GPD for a given threshold value. Scollnik (Scandinavian Actuarial Journal, 2007, 20-33, 2007) shows that the composite LN-GPD is adequate to describe body distribution and heavy-tailedness. This paper considers time-varying modeling of the LN-GPD based on local polynomial maximum likelihood estimation. Time-varying model provides significant detailed information of time dependent data, hence it can be applied to disciplines such as service engineering for staffing and resources management. Our work also extends to Beirlant and Goegebeur (Journal of Multivariate Analysis, 89, 97-118, 2004) in the sense of losing no data by including truncated lognormal distribution. Our proposed method is shown to perform adequately in simulation. Real data application to the service time of the Israel bank call center shows interesting findings on the staffing policy.