• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.45-57
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• 2019

The resident characteristics of land-based pollutants were analyzed to manage the pollution sources affecting Suyeong Bay. These characteristics were analyzed using a hydrodynamic model and particle tracking model. Pollutants were represented by particles, and the amount of particles and pollutants was represented proportional. The resident characteristics were analyzed by comparing the amount of pollutant load, resident pollutants, and the ratio of resident pollutants remaining in the bay relative to the incoming load for each the of pollution sources. The order of the pollution sources was as follows, according to the amount of resident pollutants at Suyeong Bay. the Suyeong WasteWater Treatment Plant(WWTP), Nambu WWTP, Suyeong river and so on. The amount of resident pollutants was smaller for small load farther away from the interior of bay. Nambu WWTP had the greatest load among the pollution sources, but it showed the smallest ratio of pollutants remaining in the bay relative to incoming load among the pollution points. The result indicates that pollutants affect sea areas differently according to the characteristics each area and the topographic characteristics of pollution sources.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.243-249
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• 2021

The star tracker detects microscopic star light in space and compares it with a stored list of stars to calculate the satellite's position in the inertial coordinate system. If other light, such as the sun or the earth, enters the optical head, the star cannot be recognized and the star tracker cannot be operated. In particular, strong light such as the sun affects not only operation but also the performance of the star tracker. The sun exclusion angle of the star tracker is one of the important factors determining the performance of the star tracker. This paper performs the verification of the star tracker's sun exclusion angle. In order to verify the sun exclusion angle, we predict the sun exclusion time of the star tracker and compare it to the actual sun exclusion time of the GEO-KOMPSAT-2A star tracker. In addition, the performance of the star tracker is analyzed for normal operations against the sun exclusion in the optical head. It shows that the actual sun exclusion is maintained under the range of 26 degrees, the performance requirement of the star tracker, and the star tracker operates normally in spite of the sun exclusion.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.219-225
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• 1992

Fifty patients with carcinoma of the uterine cervix received curative radiotherapy by external irradiation of the whole pelvis and intracavitary radiation at the Department of Therapeutic Radiology, Kangnam St. Mary's Hospital from September, 1983 to October, 1986. External beam whole pelvic irradiation was done first up to 4500-5940 cGy in 5 weeks to 6.5 weeks, followed by an intracavitary radiation. Total dose of radiation to point A varied from 6500 cGy to 11344 cGy (average 6764 cGy). Of the 50 patients, one patient was lost to follow up and follow up period of the remaining 49 patients ranged from 3 months to 93 months (median 32 months). According to FIGO classification, 6 ($12.2\%$) were in stage Ib, 6 ($12.2\%$) in stage IIa, 25 ($51\%$) in stage IIb, 7 ($14\%$) in stage III, and 5 ($10.2\%$) in stage IV. Age of the patients ranged from 33 to 76 years (median 60 years). Pathologically, fourty six ($94\%$) patients had squamous cell carcinoma, 2 ($4\%$) had adenocarcinoma, and 1 ($2\%$) had adenosquamous cell carcinoma. Overall response rate was $84\%$. 5-year survival rate was $49\%$ for entire group ($75\%$ for stage Ib, $83\%$ for Stage IIa, $42.5\%$ for stage IIb, $25\%$ for stage III, $40\%$ for stage IV). Complications were observed in 11 ($22.4\%$) patients, who revealed rectal complications with most common frequency. Others were self limiting trifle ones such as wet desquamation, fatigue, mild leukopenia, etc. The correlation of the survival rate with various factors (age, dose, Hb level, pelvic lymph node status, performance status, local recurrence) was evaluated but showed no statistical significance except the age and local recurrence in this series; survival of patients less than 50 years of age was worse than that of the older, and the presence of local recurrence had worse prognosis (p<0.05).

• Radiation Oncology Journal
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• v.15 no.4
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• pp.331-337
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• 1997

Purpose : To evaluate our experience in the breast-conserving treatment for early breast cancer with special regard to recurrence Pattern and related risk factors. Materials and Method :Two hundred and sixteen patients with AJC stage 1and 11 breast cancer who received breast conserving treatment between January 1991 and December 1994 were evaluated A9e distribution ranged from 23-80 year old with a median a9e of 44. One hundred and seventeen Patients had 71 lesions and 99 Patients had 72 lesions. Axillary lymph nodes were involved in 73 patients. All patients received a breast conserving surgery (wide excision to quadrantectomy) and axillary node dissection followed by radiotherapy. Ninety six patients received chemotherapy before or after radiotherapy. Results : During the follow-up period (3-60 months, median 30 months), local recurrences were noted in six Patients (true: 3, elsewhere; 1, skin: 2). Sixteen patients developed distant metastases as the first sign of recurrence at 8-38 months (median 20 months) after surgery. Among them, three patients simultaneously developed local recurrence with distant metastases. Contralateral breast cancer developed in one Patient and non-mammary cancers developed in three patients. The actuarial 5 year survival rate was $88.4\%\;(stage\;I\;96.7\%,\;stage\;IIa\;95.2\%,\;stage\;IIb\;69.9\%)$. Age, I stage, number of involved axillary lymph nodes. and AJC stage were risk factors for distant metastases in univariate analysis. In the multivariate analysis, the number of involved axillary lymph nodes was the most significant risk factor for metastases. Conclusion : Local recurrence was not common in the early years after radiotherapy. Distant metastases occurred at a steady rate during the first three years and was more common in the Patients with larger tumors, higher number of involved axillary nodes, and younger age.

• Geophysics and Geophysical Exploration
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• v.15 no.4
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• pp.190-198
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• 2012

A series of density log data were obtained from the standoff experiments made in the four physical model boreholes of different densities, and the properties of spine and rib curves have been derived by the analysis of the gamma-gamma data. Particularly, the shape of gamma ray propagation path between source and detector, the geometrical property of spine and rib curves, the influence of borehole density and the detector combination on the properties of the curves, and the adequate detector combination for standoff compensation could be discussed. It was also confirmed that spine and rib slopes can be expressed as proportional to source-to-detector distance ratio between far and near detectors. The result of this experiment was also effectively applied for understanding the basic concept of spine and rib slopes.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.5-6
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• 2016

항공전자와 같은 실시간 시스템을 위한 어플리케이션은 신뢰성을 보장하는 것이 중요하다. 기존의 동적 분석 도구가 사용하는 Sampling기법이나 Instruction측정은 성능 저하 구간을 올바르게 탐지하지 못하기 때문에 프로그램의 품질을 상승시키기 어렵고 디버깅 비용을 증가시킨다. 본 논문은 이러한 문제의 해결을 위해 함수 별 실행 시간을 측정하고, 함수의 수행 구조를 추적하여 성능저하구간을 직관적으로 식별할 수 있는 수행시간 분석 도구를 제시한다.

• Journal of Scientific & Technological Knowledge Infrastructure
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• s.5
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• pp.31-40
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• 2001

한국인의 인체 절단면 영상으로부터 인체의 3차원 데이터를 생성하였다. 다양한 종류의 3차원 렌더링 영상을 제작하고 이를 기반으로 하는 웹 기반정보시스템을 구축하였다. 인체 영상 정보시스템은 크게 렌더링에 필요한2차원 데이터를 생성하는 단계, 3차원 렌더링 데이터를 생성하는 단계, 영상을 데이터베이스화하고 이를 서비스하기 위한 시스템 구현 단계의 세 부분으로 나눌수 있다. 렌더링을 위한 2차원 영상처리는 절단면 영상의 분할과 정렬을 포함한다. 분할은 절단면 영상에 보여지는 인체의 부위를 구분하도록 하는 절차이고, 정렬은 왜곡된 영상 위치를 바로잡기 위한 절차이다. 3차원 렌더링은 절단면 영상들로부터 3차원 모델의 뷰를 생성하는 절차이다. 병렬처리를 통한 광선 추적 볼륨 렌더링 기법을 사용하여 잘라보기 및 돌려보기 렌더링 뷰를 생성한다. 각 절단면 영상 및 렌더링 영상은 인체영상 브라우저 및 검색기가 접근할 수 있도록 웹 시스템에 로드 하였다. 브라우저는 인체의 위치를 시각적으로 탐색 할 수 있도록 구현되었다. 각 단계별 기술적인 내용을 소개한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.642-644
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• 2022

In this paper, we propose a dynamic Web-Dashboard application so that resource information can be accessed anytime, anywhere, and management efficiency improvement analysis through big data analysis using various progressive analysis functions. It provides visualization and analytics to provide rich analytical insights to track resource location, predict repurchase duration, or find cost savings and efficiencies.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.43-49
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• 2017

In the analyzed cardiac CT algorithm applied when comparing the MAR self-made metal artifact reduction in pacemaker inserted phantom degree. Result of comparing the energy value by CT showed a decrease in the CT value in the case of BKG 40 KeV in WSA maximum decreased to 663.2% in the case of 140 KeV BHA were increased a maximum of 56.2%. In addition, the maximum was decreased by approximately 145% based on a 70 KeV artifacts in CT value comparison by type WSA, BHA was to increase up to approximately 46.38%. MAR Algorithm is believed to provide a more quality cardiac CT image if the energy changes, or have the effect that by type and irrespective of reduced metal artifacts occurrence of artifacts applied to the pacemaker when tracking a heart CT scan after inserting MAR algorithm.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.2233-2237
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• 2008

기존 댐저수지 유입량 산정은 수위-저수량곡선에 댐축에서 측정된 수위를 적용하여 시간당 저수량변화를 계산한 후 방류량을 감안하여 산정하고 있으나, 특히 홍수시 저수지내의 수위가 균일하지 않아 유입량 산정 시 오차 원인이 되고 있다. 홍수기 댐 저수지의 운영에 있어서 가장 큰 불확실도를 가지고 있는 유입량의 정확한 모의를 위해서는 유역 상류 유입부 유량뿐 아니라 저수지 내에서의 수위관측 필요하며, 또한 기존 방법에 의한 유입량 계산의 오차 규명 필요하다. 이러한 문제점을 해결하기 위해서는 GIS를 이용한 저수지의 저수위-저류량곡선 개선 및 댐저수지 구간별 수위관측을 통한 실시간 홍수 유입량 산정 시스템 도입이 절실히 요구되고 있는 실정이다. 본 연구에서 현행 댐 저수지에서 운영되고 있는 수위관측소를 포함하여 관측지점을 확대하고 실시간 수위관측이 가능한 통신체계를 구축하고자 하였다. 관측지점의 확대는 기존의 문제점을 해결하는데 있어 주요 지점의 수면 프로파일을 구축하여 호내 유입량 산정에 대한 재검토를 진행하고자 하였으며, 이를 위해 구간별 수위 모의가 가능한 HEC-RAS 모형을 이용하여 저수지 내의 수면곡선 분포를 모의하고 저수지 내에서 관측한 수위자료와 비교하였다. 또한 관측된 수위자료의 체계적인 관리 체계 구축을 위해 실시간 모니터링이 가능하고, 통신망의 안전성 확보를 통한 결측 자료가 발생하지 않도록 USN Gateway와 CDMA를 연동하여 통신망을 구성하였다. 나아가, 댐 저수지 유입량 산정에 대한 재검토와 실시간 수위관측 방법에 대한 신기술 도입을 통하여 물관리 부서에 즉시 적용이 가능하도록 유입량 산정 방법과 센서 기술 적용 방법 및 확장성을 제시하였다.