• Journal of Korea Multimedia Society
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• v.7 no.9
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• pp.1246-1254
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• 2004

This paper presents a image coding method that is well adaptive to close-range video transmission because of its low titrate and simple coding procedure. At first, it reduces temporal redundancies by performing image DPCM between previous frame and current frame, and makes wavelet transformed image of this difference image. Then, the coefficients are quantized selectively by using the coefficient values of base level and mid-frequency level because inter-level redundancies are widely exists in multi-resolution images. Finally quantized coefficients are made iron the function that implies the target bitrate, the average coefficient energy, and the value of the level. The proposed method shows the effective Performance in the experiments using the continuous motion images and transition images.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.156-156
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• 2012

최근 우리나라의 대부분을 차지하는 중소규모 하천 또는 도시하천은 하천수 및 하천변 지하수 이용의 증가와 토지이용변화 등으로 인해 하천의 건천화가 점증하고 있어 하천의 생태와 건전한 환경이 악화되고 있는 실정이다. 본 연구는 이러한 중소규모 하천 또는 도시하천의 도시화율에 따른 정량화된 건천화의 평가지표를 제시하고 하천 관리지표로 활용하며, 건천화 원인을 분석하여 실용적인 건천화 해소대책을 제시하는데 그 목적이 있다. 이를 위하여 건천화 원인조사 및 원인별 영향 평가에 대하여 국내외 연구사례를 조사, 분석하여 도시화율에 따른 건천화 평가 기준을 개발하고, 연구지역에 적용하여 도시화율에 따른 정량적인 건천화 평가를 수행하였다. 본 연구의 대상유역은 남천, 갑천, 경안천, 왕숙천으로 총 4개 유역으로 최근 도시화에 따라 불투수율 증가, 지하수 사용량 증가 등으로 건천화가 진행중인 하천이다. 각 유역은 본 연구에서 제안하는 건천화 평가기법에 따라 본 연구에서 제안하는 건천화 등급 1~5심도로 평가되었으며, SWMM_GE 프로그램으로 분석된 유출량과 다변량 분석 방법을 이용하여 불투수율과 지하수사용량에 따른 기저유출 관계식을 산출하였다. 연구 결과는 향후 대상유역의 하천유지유량 확보 등 유역의 물건전화 정책에 도움이 될 것으로 판단된다.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.619-624
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• 2008

Background: Secondary spontaneous pneumothorax is caused by various underlying lung diseases, and this is despite that primary spontaneous pneumotherax is caused by rupture of subpleural blebs. The treatment algorithm for secondary pneumothorax is different from that for primary pneumothorax. We studied the recurrence rate, the characteristics of recurrence and the treatment outcomes of the patients with secondary spontaneous pneumothorax. Material and Method: Between March 2005 to March 2007, 85 patients were treated for their first episodes of secondary spontaneous pneumothorax. We analyzed the characteristics and factors for recurrence of secondary spontaneous pneumothorax by conducting a retrospective review of the medical records. Result: The most common underlying lung disease was pulmonary tuberculosis (49.4%), and the second was chronic obstructive lung disease (27.6%), The recurrence rate was 47.1% (40/85). The second and third recurrence rates were 10.9% and 3.5%, respectively. The mean follow up period was $21.1{\pm}6.7$ months (range: $0{\sim}36$ month). For the recurrence cases, 70.5% of them occurred within a year after the first episode. The success rates according to the treatment modalities were thoracostomy 47.6%, chemical pleurodesis 74.4%, blob resection 71% and Heimlich valve application 50%. Chemical pleurodesis through the chest tube was the most effective method of treatment. The factor that was most predictive of recurrence was 'an air-leak of 7 days or more' at the first episode. (p=0.002) Conclusion: The patients who have a prolonged air-leak at the first episode of pneumothorax tend to have a higher incidence of recurrence. Further studies with more patients are necessary to determine the standard treatment protocol for secondary spontaneous pneumothorax.

• Tuberculosis and Respiratory Diseases
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• v.62 no.5
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• pp.398-405
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• 2007

Background: There is little data on the 3 year prognosis and quality of life of patients on long-term (>72 hour) mechanical ventilation in a medical intensive care unit (MICU). Methods: Patients with long-term mechanical ventilation from May 2003 through July 2003 in MICU of Asan Medical Center, Seoul were enrolled in this studay. The survival rates were observed prospectively at 1, 3, 6, 12, 24, 36 months, and the quality of life of survivor was measured at 12 months by using Short Form 36 (SF-36). Results: The survival rate at 1, 3, 6, 12, 24 and 36 months was 54.8% (40/73), 39.7% (29/73), 30.1% (22/73), 20.5% (15/73), 18.3% (13/71) and 16.9% (12/71), respectively. There was a similar survival rate regardless of the diseases that required mechanical ventilation. A neoplasm or chronic liver disease had a worse survival rate than chronic lung or kidney disease (p<0.05). Each SF-36 domain except for the Role-emotional was inferior to the general population. Conclusions: The survival rate of patients with mechanical ventilation more than 72 hours is decreases continuously until 12 months but is relatively constant from 12 to 36 months. In these patients quality of life is also decrased.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.2
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• pp.125-131
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• 2007

Objective: The aim of this study was to compare GnRH antagonist and agonist flare-up treatment in the management of poor responder patients. Methods: One hundred forty-four patients from Jan. 1, 2002 to Aug. 31, 2005 undergoing IVF/ICSI treatment who responded poorly to the previous cycle (No. of oocyte retrieved$\leq$5) and had high early follicular phase follicle stimulating hormone (FSH>12 mIU/ml were selected. Seventy-five patients received agonist flare-up protocol and 71 patients received antagonist protocol. We analyzed the number of oocytes retrieved, number of good embryos (GI, GI-1), total dose of hMG administered, implantation rate, cycle cancellation rate, pregnancy rate, live birth rate. Results: The cancellation rate was high in antagonist protocol (53.5% vs. 30.1%). The number of oocyte retrieved, the number of good embyos were high in agonist flare-up group. There was no statistical difference between GnRH agonist flare up protocol and GnRH antagonist protocol in implantation rate (14.5%, 10.1%), clinical pregnancy rate per transfer (29.4%, 21.2%) and live birth rate per transfer (21.6%, 18.2%). Although the result was not statistically significant, GnRH agonist flare up group showed a nearly doubled pregnancy rate and live birth rate per initial cycle than GnRH antagonist group. Conclusions: The agonist flare-up protocol appears to be slightly more effective than the GnRH antagonist protocol in implantation rate, pregnancy rate, live birth rate but shows statistically no significance. Agonist flare-up protocol improved the ovarian response in poor responders. However, based of the result of the study, we can expect improved ovarian response in poor responders by GnRH agonist flare up protocol.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.67-72
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• 2003

제주도 동부지역에 설치한 심부관측정과 지하수 개발공에 대한 시추코아 지질검층, EC 및 수온검층, 지하수위 관측, 수질조사 등의 자료를 기초로 이 지역의 지하지질 분포와 지하수 부존특성에 대해 해석을 실시하였다. 제주도 동부 해발 200m 이하지역은 평균 해수면 하 90~120m 깊이까지 투수성이 좋은 용암류 누층으로 이뤄져 있으며, 일부지역에서는 서귀포층 상부에 유리쇄 설성 각력암층(hyaloclastite breccia)이 두껍게 분포하고 있어 담수지하수의 확산과 해수의 유입이 잘 일어날 수 있는 지질상태를 이루고 있다. 특히 서귀포층은 G-H비에 의한 담.염수 경계면 분포 깊이보다 깊은 위치에 존재하고 있어 제주도 서부지역에서처럼 담수지하수를 저류 해주는 역할을 기대하기 어려운 것으로 판단된다. 제주도 동부지역 지하수체는 수직적으로 담수지하수, 저염지하수, 염수지하수로 구분할 수 있으며, Ghyben-Herzberg 원리가 적용되는 담수렌즈(기저지하수) 두께는 일반적인 G-H비 보다 훨씬 얇은 평균 1:20의 비율을 나타냈다. 담수렌즈는 대체로 해안으로부터 내륙쪽 8km 지역까지 광범위하게 발달하고 있으며, 담수렌즈 포장량은 822백만톤(공극율 5%)에서 1,970백만톤(공극율 12%)의 범위로 추정되었다.

• The Korean Journal of Nuclear Medicine
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• v.37 no.3
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• pp.178-189
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• 2003

Purpose: Cellular uptakes of $^{99m}Tc-sestamibi(MIBI)\;and\;\;^{99m}Tc-tetrofosmin$ into cancer cell lines expressing multidrug resistance(MDR) were investigated and compared. The effects of verapamil and cyclosporin A, well-known multidrug resistant reversing agents, on cellular uptakes of both tracers were also compared. Materials and Methods: Doxorubicin-resistant HCT15/CL02 human colorectal cell and doxorubicin-resistant K562(Adr) and vincristine-resistant K562(Vcr) human leukemic cells were studied. RT-PCR analysis was used for the detection of mdr1 mRNA expression. MDR-reversal effects with verapamil and cyclosporine A were evaluated at different drug concentrations after incubation with MIBI and tetrofosmin for 1, 15, 30, 45 and 60 min, using single-cell suspensions at $1{\times}10^6cells/ml$ incubated at $37^{\circ}C$. Radioactivity in supernatants and pellets were measured with gamma well counter. Results: The cellular uptakes of MIBI and tetrofosmin in K562(Adr) and K562(Vcr) were lower than those of parental K562 cell. In HCT15/CL02 cells and K562(Adr) cells, there were no significant difference in cellular uptakes of both tracers, but cellular uptake of MIBI was higher than that of tetrofosmin in K562(Vcr) cells. Coincubation with verapamil resulted in a increase In cellular uptakes of MIBI and tetrofosmin. Verapamil increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 11.9- and 6.8-fold, by K562(Adr) cell by 14.3- and 8-fold and by K562(Vcr) cell by 7- and 5.7-fold in maximum, respectively. Cyciosporin A increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 10- and 2.4-fold, by K562(Adr) cell by 44- and 13-fold and by K562(Vcr) cell by 18.8- and 11.8-fold in maximum, respectively Conclusion: Taking together, MIBI and tetrofosmin are considered as suitable radiopharmaceuticals for defecting multidrug resistance. However, MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators. Since cellular uptakes of both tracers might differ in different cell types, further experiments regarding differences in cellular uptakes between cell types should be explored.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.147-152
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• 2021

This study is a retrospective analysis of the results of tests at three general hospitals in Busan that perform mammography using digital mammography devices. There were 5,320 people in the study, and the results of their breast cancer screening were analyzed to verify the efficacy of breast cancer screening for digital mammography. The average age of patients who performed breast cancer screening was 57.7 years (range 30 to 87 years), and the cancer detection rate was 26, with 4.6 cases per 1,000 people. According to the cancer detection rate by risk factor in patients who conducted breast cancer screening, breast cancer was found in patients without underlying diseases more than in patients with underlying diseases. Additional ultrasound examinations show that the gastronomic rate identified is 3.6%, which is relatively very low compared to that of the Film-Screen system.

• Applied Microscopy
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• v.33 no.4
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• pp.315-323
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• 2003

The fine structural characteristics of the spinnerets and spigots of the silk producing apparatus in the adult funnel-web spider, Agelena limbata, were analysed with the light and scanning electron microscopes. Silk producing apparatus of this spider was composed of three pairs of spinnerets (anterior, median, posterior) and four different types of spigots-ampullates, tubuliforms, pyriforms and aciniforms. By the examination of their ultrastructural characteristics, it has been revealed that each spigot on the spinnerets are connected through the typical silk gland within abdominal cavity. Among the three pairs of spinnerets, the posterior pairs were highly elongated and has most characteristic features. Two pairs of large ampullates were connected to anterior spinneret and another two pairs of small ampullates to median spinnerets. Spigots of the tubuliforms were observed only in female and were connected both of median and posterior spinnerets respectively. While spigots of the pyriforms were connected on the anterior spinnerets but aciniforms on both of median and posterior spinnerets respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2313-2327
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• 1994

As the communication environment evolves, there is an increasing need for multiresolution image coding. To meet this need, the entrophy constratined vector quantizer(ECVQ) for coding of image pyramids by spline wavelet transform is introduced in this paper. This paper proposes a new scheme for image compression taking into account psychovisual feature both in the space and frequency domains : this proposed method involves two steps. First we use spline wavelet transform in order to obtain a set of biorthogonal subclasses of images ; the original image is decomposed at different scale using a pyramidal algorithm architecture. The decomposition is along the vertical and horizontal directions and maintains constant the number of pixels required the image. Second, according to Shannon's rate distortion theory, the wavelet coefficients are vectored quantized using a multi-resolution ECVQ(entropy-constrained vector quantizer) codebook. The simulation results showed that the proposed method could achieve higher quality LENA image improved by about 2.0 dB than that of the ECVQ using other wavelet at 0.5 bpp and, by about 0.5 dB at 1.0 bpp, and reduce the block effect and the edge degradation.