• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.479-480
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• 2023

현대 사회는 출생아가 줄어들고 고령화 현상이 빠르게 진행 중이다. 20~30대의 사회 복지 종사자가 줄어들고 노인 인구는 늘어나는 반비례 현상이 나타나고 있다. 보호자가 없는 노인에게 낙상 사고와 같은 위급상황이 발생한다면 골든타임을 놓칠 수도 있을 것이다. 따라서, 본 논문에서는 낙상 사고 발생 시, 빠른 시간 내에 실시간 모니터링을 통해 노인 복지사가 상황을 인지할 수 있게 하는 시스템을 개발하였다. 미디어파이프 포즈 모델을 이용하여 관찰 대상의 움직임을 포착하도록 하였고 PTZ 카메라의 서보 모터 제어를 통해 포착한 관찰 대상을 추적하도록 하였다. 주요 장면은 사진으로 저장해 웹 서버로 전송하고, 심박수 측정 센서와 와이파이 통신 모듈이 장착된 아두이노 보드가 실시간으로 웹 서버로 전송하여, 전담 관리자는 사진을 통해 상황을 인식하고 심박수를 보고 얼마나 위급한지 알 수 있도록 하였다.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.226-232
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• 2000

Purpose :This study was performed to find out the prognostic factors affecting local control in early glottic cancer treated with radiation therapy alone. Materials and Methods :We analysed 37 patients of histologically confirmed early glottic cancer treated at Chonnam National University Hospital between July Im and December 1995, retrospectively. Age of patients ranged from 30 to 73 years (median; 59 years). Thirty-five (95$\%$) patients were male. Histological type was all squamous cell carcinoma. According to the staging system of 1997 American Joint Committee on Cancer, 37 patients were restaged as follows: Tla; U (73$\%$), Tlb; 3 (8$\%$), 72: 7 (19$\%$). Radiation therapy was done using 6 MV X-ray of linear accelerator The range of total radiation dose delivered to the glottic lesion was between 5,040 cGy and 7,020 cGy (median; 6,600 cGy). Median follow-up period was U months. local control rates were calculated by Kaplan-Meier method. Generalized Wilcoxon test was used to evaluate the difference of control rates between comparable groups. Multivariate analysis using Cox proportional hazard model was done to find out prognostic factors affecting local control. Results:5 year survival rate of 37 patients was 89$\%$. Local control rate of 37 patients was 74$\%$ in 5 years. We included age, 7-stage, anterior commissure involvement, fraction size, total radiation dose, treatment time of radiotherapy as potential prognostic factors in univariate and multivariate analysis. As a result, treatment time had statistical significance in local control rate in both univariate (p=0.026) and multivariate (p=0.017) analysis. Complication was not recorded except one patient with hypothyroidism. Conclusion :This study revealed that overall treatment time of radiation was a significant factor affecting local control rate.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.230-236
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• 2001

Purpose : To evaluate treatment results in terms of local control, complications and survival after reirraidiation in recurrent cervical cancer following definite radiation therapy. Material and methods : From November 1987 through March 1998, eighteen patients with recurrent cervical cancer following definite radiation therapy were subsequently treated with reirradiation at Keimyung University Dongsan Medical Center. In regard to the initial FIGO stage, one patient was stage la, five were stage IIa, three were IIb, two were IIb and two were IVa. The age range was 37 to 79 years old with median age of 57. The time interval from initial definite radiation therapy to recurrence ranged from 6 to 122 months with a median of 58 months. The recurrent sites were the uterine cervix in seven patients, vagina in ten and pelvic lymph node in one. Reirradiation was peformed with external radiation and intracavitary radiation in twelve patients, external radiation and implantation in four and external radiation alone in two. The range of external radiation dose was $2,100\~5,400\;cGy$ and the range of the total radiation dose was $3,780\~8,550\;cGy$. The follow-up periods ranged from 8 to 20 months with median of 25 following reirradiation. Results : Fourteen of eighteen patients $(78\%)$ had local control just after reirradiation. The two year disease free survival (2YDFS) rate was $53.6\%$. There were statistically significant differences in the 2YDFS according to both recurrent site (2YDFS $28.5\%$ in uterine cervix, $71.4\%$ in vagina, (p=0.03)) and the total dose (2YDFS $71.8\%$ in >6,000 cGy , $25\%$ in $\leq6,000$ cGy, p=0.007). Seven of ten patients who were followed for more than 20 months remain alive and disease free (7/18, $39\%$). Patients treated with external radiation and intracavitary radiation had a higher rate of 2YDFS. Seven patients including 4 patients with no local control experienced local failure in the uterus or vagina and two patients died with distant metastasis. Complications included rectal bleeding in 3 patients, bowel obstruction treated with surgery in two, hematuria in one, radiation cystitis in two, soft tissue swelling in two and vaginal necrosis spontaneously healed in one. There was no statistical difference in complications according to the total dose or the time to recurrence from initial radiation. Conclusion : In patients with recurrence following definite radiation therapy in the uterine cervical cancer, reirradiation may be effective but requires an effort to reduce radiation induced severe complications.

• Radiation Oncology Journal
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• v.29 no.1
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• pp.20-27
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• 2011

Purpose: This study was designed to evaluate the results of local control, survival rate, prognostic factors, and failure pattern in locally advanced esophageal cancer. Materials and Methods: We retrospectively studied 50 patients with locally advanced esophageal cancer treated with concurrent chemoradiotherapy at Keimyung University Dongsan Medical Center from June of 1999 to August of 2008. Seven patients with inappropriate data were excluded, and 43 patients were analyzed. There were 39 males and four female patients ranging in age from 43 to 78 years (median, 63 years). There were seven patients with stage IIA and 36 with stage III. Irradiation from 46 Gy to 63 Gy (median, 54 Gy) was carried out 5 days per week, 1.8 Gy once a day. There were eight patients with neo-adjuvant chemotherapy, and we mostly used 5-fluorouracil, cisplatin with 3 cycles for concurrent chemotherapy. The range of follow up periods was from 2 to 82 months (median, 15.5). Results: There were nine patients that exhibited a cornplete response, 23 that exhibited a partial response, 9 that exhibited no response, and 2 that exhibited disease progression. The median survival time was 15 months. Two-year and 5-year survival rates were 36.5% and 17.3%, respectively. Two-year and 5-year disease-free survival rates were 32.4% and 16%, respectively. Treatment failure occurred in 22 patients (51.2%). Patterns of failure were categorized as local failure in 18 patients and distant metastasis in four patients. In a univariate analysis for prognostic factors related to overall survival and disease-free survival, the hemoglobin levels during chemoradiotherapy (${\geq}$ 12 vs. <12, p=0.02(p=0.1) and the response to the treatments (CR/PR vs. NR/PD, p=0.002/p< 0.0001) were statistically significant. In a multivariate analysis, only response to the treatments was revealed to be statistically significant. There was no statistical significance associated with patient age, gender, disease stage, T-stage, smoking history, tumor location, or neo-adjuvant chemotherapy. Conclusion: Our survival rate was similar to those of other institutions. Local recurrence was the main reason for failure. It is suggested that further prospective studies should be performed to improve local control.

• Progress in Medical Physics
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• v.23 no.2
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• pp.91-98
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• 2012

Verification of internal organ motion during treatment and its feedback is essential to accurate dose delivery to the moving target. We developed an offline based internal organ motion verification system (IMVS) using cine EPID images and evaluated its accuracy and availability through phantom study. For verification of organ motion using live cine EPID images, a pattern matching algorithm using an internal surrogate, which is very distinguishable and represents organ motion in the treatment field, like diaphragm, was employed in the self-developed analysis software. For the system performance test, we developed a linear motion phantom, which consists of a human body shaped phantom with a fake tumor in the lung, linear motion cart, and control software. The phantom was operated with a motion of 2 cm at 4 sec per cycle and cine EPID images were obtained at a rate of 3.3 and 6.6 frames per sec (2 MU/frame) with $1,024{\times}768$ pixel counts in a linear accelerator (10 MVX). Organ motion of the target was tracked using self-developed analysis software. Results were compared with planned data of the motion phantom and data from the video image based tracking system (RPM, Varian, USA) using an external surrogate in order to evaluate its accuracy. For quantitative analysis, we analyzed correlation between two data sets in terms of average cycle (peak to peak), amplitude, and pattern (RMS, root mean square) of motion. Averages for the cycle of motion from IMVS and RPM system were $3.98{\pm}0.11$ (IMVS 3.3 fps), $4.005{\pm}0.001$ (IMVS 6.6 fps), and $3.95{\pm}0.02$ (RPM), respectively, and showed good agreement on real value (4 sec/cycle). Average of the amplitude of motion tracked by our system showed $1.85{\pm}0.02$ cm (3.3 fps) and $1.94{\pm}0.02$ cm (6.6 fps) as showed a slightly different value, 0.15 (7.5% error) and 0.06 (3% error) cm, respectively, compared with the actual value (2 cm), due to time resolution for image acquisition. In analysis of pattern of motion, the value of the RMS from the cine EPID image in 3.3 fps (0.1044) grew slightly compared with data from 6.6 fps (0.0480). The organ motion verification system using sequential cine EPID images with an internal surrogate showed good representation of its motion within 3% error in a preliminary phantom study. The system can be implemented for clinical purposes, which include organ motion verification during treatment, compared with 4D treatment planning data, and its feedback for accurate dose delivery to the moving target.

• Progress in Medical Physics
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• v.18 no.1
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• pp.27-34
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• 2007

Respiration sating radiotherapy technique developed In consideration of the movement of body surface and Internal organs during respiration, is categorized into the method of analyzing the respiratory volume for data processing and that of keeping track of fiducial landmark or dermatologic markers based on radiography. However, since these methods require high-priced equipments for treatment and are used for the specific radiotherapy. Therefore, we should develop new essential method whilst ruling out the possible problems. This study alms to obtain body surface motion by using the couch based computer-controlled motion phantom (CBMP) and US sensor, and to develop respiration gating techniques that can adjust patients' beds by using opposite values of the data obtained. The CBMP made to measure body surface motion is composed of a BS II microprocessor, sensor, host computer and stopping motor etc. And the program to control and operate It was developed. After the CBMP was adjusted by entering random movement data, and the phantom movements were acquired using the sensors, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using a rabbit, the real-time respiration gating techniques were drawn by operating the phantom with the opposite values of the data. The result of analysing the acquisition-correction delay time for the data value shows that the data value coincided within 1% and that the acquistition-correction delay time was obtained real-time $(2.34{\times}10^{-4}sec)$. And the movement was the maximum movement was 6 mm In Z direction, In which the respiratory cycle was 2.9 seconds. This study successfully confirms the clinical application possibility of respiration gating techniques by using a CBWP and sensor.

• Journal of the Korea Society of Computer and Information
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• v.19 no.8
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• pp.35-44
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• 2014

This paper proposes a 3D pointing interface that is designed for the efficient application of a hand mouse. The proposed method uses depth images to secure high-quality results even in response to changes in lighting and environmental conditions and uses the normal vector of the palm of the hand to perform 3D pointing. First, the hand region is detected and tracked using the existing conventional method; based on the information thus obtained, the region of the palm is predicted and the region of interest is obtained. Once the region of interest has been identified, this region is approximated by the plane equation and the normal vector is extracted. Next, to ensure stable control, interpolation is performed using the extracted normal vector and the intersection point is detected. For stability and efficiency, the dynamic weight using the sigmoid function is applied to the above detected intersection point, and finally, this is converted into the 2D coordinate system. This paper explains the methods of detecting the region of interest and the direction vector and proposes a method of interpolating and applying the dynamic weight in order to stabilize control. Lastly, qualitative and quantitative analyses are performed on the proposed 3D pointing method to verify its ability to deliver stable control.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.682-691
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• 2005

We present a two-step evolution system that produces controllable virtual creatures in physically simulated 3D environment. Previous evolutionary methods for virtual creatures did not allow any user intervention during evolution process, because they generated a creature's shape, locomotion, and high-level behaviors such as target-following and obstacle avoidance simultaneously by one-time evolution process. In this work, we divide a single system into manageable two sub-systems, and this more likely allowsuser interaction. In the first stage, a body structure and low-level motor controllers of a creature for straight movement are generated by an evolutionary algorithm. Next, a high-level control to follow a given path is achieved by a neural network. The connection weights of the neural network are optimized by a genetic algorithm. The evolved controller could follow any given path fairly well. Moreover, users can choose or abort creatures according to their taste before the entire evolution process is finished. This paper also presents a new sinusoidal controller and a simplified hydrodynamics model for a capped-cylinder, which is the basic body primitive of a creature.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.161-170
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• 1998

기존에 건설된 교통시설의 운영효율을 극대화하기 위한 지능형 교통체계의 한 분야인 ATIS는 도로를 이용하는 통행자에게 편리성을 제공하는 동시에 도로를 효율적으로 운영할 수 있는 정보체계이다. ATIS 체계하에서 통행자에게 신뢰성 있는 정보를 제공하기 위해서는 교차로서의 회전에 의한 지체를 정확하게 반영함은 물론이고 실시간으로 변화하는 교통상황을 반영할 수 있는 동적인 최단경로 탐색 알고리즘이 요구된다. 하지만 기존에 발표된 동적인 최단경로 탐색 알고리즘은 회전에 대한 정보를 반영하지 못하며 정적인 최단경로 탐색 알고리즘은 회전에 대한 정보를 반영하지 못하며 정적인 탐색알고리즘 조차 회전에 대한 정보를 정확히 반영하지 못한다. 본 연구에서는 이러한 이유에서 알고리즘 내부에서 회전을 반영하기 위해 수정형 덩굴망 알고리즘의 표지기법을 이용하여 동적인 최단경로 탐색알고리즘을 개발하였다. 본 연구에서 개발한 동적 최단경로 탐색 알고리즘은 정적인 상태의 수정형 덩굴망 알고리즘에 시간에 따라 변화하는 교통상황을 반영하기 위해 시간에 대한 변수를 추가하였다. 이렇게 해서 알고리즘은 시간대별로 변화하는 통행시간을 고려하여 최단 경로를 탐색하게 되며 출발시점을 기준으로 표지를 설정하여 모든 앞선 시간에 대해 경로를 고려하도록 하였다. 매 단계에서 전 노드를 추적하여 회전에 관한 정보를 반영하도록 하였다. 따라서 본 연구에서 개발한 최단경로 탐색 알고리즘은 교차로에서의 회전에 대한 정보와 통행금지 등을 정확히 반영하며 실시간으로 변화하는 통행시간을 반영함으로써 신뢰성 있는 노선 정보를 ATIS를 이용하는 통행자들에게 제공하는데 활용될 수 있는 기법이다.적으로 세부적 차종분류로 접근한다.의 영향들을 고려함으로써 가로망 설계 과정에서 가로망의 상반된 역할인 이동성과 접근성의 비교가 가능한 보다 현실적인 가로망 설계 모형을 구축하고자 한다. 지금까지 소개된 가로망 설계모형들은 용량변화에 대한 설계변수의 형태에 따라 이산적 가로망 설계 모형과 연속적 가로망 설계모형으로 나뉘어지게 된다. 본 논문의 경우, 계산속도의 향상 측면에서는 연속적 가로망 설계 모형을 도입할 수 있지만, 이때 요구되는 도로용량이 이산적인 변수(차선 수)로 결정되어야만 신호제어 변수를 결정할 수 있기 때문에, 이산적 가로망 설계 모형이 사용된다. 하지만, 이산적 설계모형의 경우 조합최적화 문제이므로 정확한 최적해를 구하기 위해서는 상당한 시간이 소요되며, 경우에 따라서는 국부 최적해에 빠지게 된다. 이러한 문제를 극복하기 위해, 우선 이상적 모형의 근사화, 혹은 조합최적화문제를 위해 개발된 Simulated Annealing기법의 적용, 연속적 모형의 변수를 이산화하는 방법 등 다양한 모형들을 고려해 본 뒤, 적절한 모형을 적용할 것이다. 가로망 설계 모형에서 신호제어를 고려하기 위해서는 주어진 가로망에 대한 통행 배정과정에서 고려되는 통행시간을 링크통행시간과 교차로 지체시간을 동시에 고려해야 하는데, 이러한 문제의 해결을 위해서 최근 활발히 논의되고 있는 교차로에서의 신호제어에 대응하는 통행배정 모형을 도입하여 고려하고자 한다. 이를 위해서 지금까지 연구되어온 Global Solution Approach와 Iterative Approach를 비교, 검토한 뒤 모형에 보다 알맞은 방법을 선택한다. 차량의 교차로 통행을 고려하는 perf

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.214-214
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• 1999

다이아몬드를 반도체용 열방산용기판 등으로 사용하기 위해서는 수백 $\mu\textrm{m}$ 두께의 대면적 웨이퍼가 요구된다. 이를 위해서 DC are jet CVD, MW PACVD, DC PACVD 등이 개발되어, 현재 4"에서 8"까지의 많은 문제를 일으키고 있다. 본 연구에서는 multi-cathode DC PACVD법에 의한 4" 다이아몬드 웨이퍼의 합성과 합성된 막의 특성변화에 대한 연구를 수행하였다. 또한, 웨이퍼의 휨과 crack 발생거동과 대한 고찰을 통래 휨과 crack이 없는 웨이퍼의 제작방법을 고안하였다. 사용된 음극의 수는 일곱 개이며, 투입된 power는 각 음극 당 약 2.5kW(4.1 A-600V)이었다. 사용된 기판의 크기는 직경 4"이었다. 합성압력은 100Torr, 가스유량은 150sccm, 증착온도는 125$0^{\circ}C$~131$0^{\circ}C$, 수소가스네 메탄조성은 5%~8%이었다. 합성 중 막에 인가되는 응력은 합성 중 증착온도의 변화에 의해 제어하였다. 막의 결정도는 Raman spectroscopy 및 열전도도를 측정을 통해 분석하였다. 성장속도 및 다이아몬드 peak의 반가폭은 메탄조성 증가(5%~8%)에 따라 증가하여 각각 6.6~10.5$\mu\textrm{m}$/h 및 3.8~5.2 cm-1의 분포를 보였다. 6%CH4 및 7%CH4에서 합성된 웨이퍼에서 측정된 막의 열전도도는 11W/cmK~13W/cmK 정도로 높게 나타났다. 막두께의 uniformity는 최대 3.5%로 매우 균일하였다. 막에 인가되는 응력의 제어로 직경 4"k 합성면적에서 두께 1mm 이상의 균열 및 휨이 없는 다이아몬드 자유막 웨이퍼를 합성할 수 있었다.다이아몬드 자유막 웨이퍼를 합성할 수 있었다.active ion에 의해 sputtering 이 된다. 이때 plasma 처리기의 polymer 기판 후면에 magnet를 설치하여 높은 ionization을 발생시켜 처리 효과를 한층 높여 주었다. 이 plasma 처리는 표면 청정화, 표면 etching 이 동시에 행하는 것과 함께 장시간 처리에 의해 표면에서는 미세한 과, C=C기, -C-O-의 극성기의 도입에 의한 표면 개량이 된다는 것을 관찰할 수 있다. OPP polymer 표면을 Ar 100%로 plasma 처리한 경우 C-O, C=O 등의 carbonyl가 발생됨을 알 수 있었다. C-O, C=O 등의 carbynyl polor group이 도입됨에 따라 sputter된 Al의 접착력이 향상됨을 알 수 있으며, TEM 관찰 결과 grain size도 상당히 작아짐을 알 수 있었다.onte-Carlo 방법으로 처리하였다. 정지기장해석의 경우 상용 S/W인 Vector Fields를 사용하였다. 이를 통해 sputter 내 플라즈마 특성, target으로 입사하는 이온에너지 및 각 분포, 이들이 target erosion 형상에 미치는 영향을 살펴보았다. 또한 이들 결과로부터 간단한 sputtering 모델을 사용하여 target으로부터 sputter된 입자들이 substrate에 부착되는 현상을 Monte-Carlo 방법으로 추적하여 성막특성도 살펴보았다.다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품 개발에 따른 새로운 수요 창출과 수익률 향상, 기존의 기능성 안료를 나노(nano)화하여 나노 입자를 제조, 기존의 기능성 안료에 대한 비용 절감 효과등을 유도 할 수 있다. 역시 기술적인 측면에서도 특수소재 개발에 있어 최적의 나노 입자 제어기술 개발 및 나노입자를 기능성 소재로 사용하여 새로운 제품의 제조와 고압 기상