• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.72-81
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• 1994

Total 55 patients with nonsmall cell lung cancer treated with radiation therapy at Department of Therapeutic Radiology, Yeungnam University Hospital, between May-1 1986 and April-30 1993 were retrospectively analyzed by clinical characteristics, failure patterns, follow up duration and survival ratio according to prognostic factors. Obtained results were as follows : 1. Male to female ratio was 17.3 2. Sixth and seventh decades were predominant age group. 3. The patients were 8 in stage I-II, 34 in stage IIIA, 13 in stage IIIb, respectively. 4. Forty five patients out of 55 were squamous cell carcinoma. 5. Primary tumor were originated from upper lobe bronchi predominantly. 6. The size of the primary tumor, lymph node involvement and the degree of differentiation were important in evaluation of prognosis. 7. In conclusion, for patients with poor prognostic factors systemic chemotherapy and multidisciplinary approach were recommended for better treatment outcome and improvement of survival.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.41-48
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• 1995

Purpose : The adjuvant postoperative radiotherapy has been usually applied to the patients with unfavorable prognostic factors after radical operation in early cervical cancer. We focused on the evaluation of the survival status and failure patterns of the patients with postoperative radiotherapy. Materials and Methods : We retrospectively analyzed ninety patients with FIGO stage IB and IIA cervix cancer who received postoperative pelvic irradiation at Chonnam University Hospital between August 1985 and December 1988, Seventy-eight patients had adequate follow-up information for survival analysis. Median follow-up time of these patients was 64 months. Results : The 5 year overall and disease free survival rate of ninety patients was $80.0\%$ and $80.2\%$, respectively. The prognostic significance to the survival was determined by multivariate analysis. Adequacy of resection margin(p=0.005) and lymph node status(p=0.005) appeared to be independent prognostic factors. Recurrence occurred in 13 patients, 5 in the pelvis and 8 at distant sites. The median time to recurrence was 19 months(range:3-39 months). The pelvic recurrence was more prevalent in the group of patients with adenocarcinoma, depth of stromal invasion more than 10mm and use of chemotherapy. The distant failure was more prevalent in the group of positive resection margin or positive lymph node with statistical significance. Conclusion : Patients with pelvic lymph node or surgical margin involvement clearly constitute a high risk group in this analysis and should be considered as candidates for some form of adjuvant therapy.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.103-103
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• 1993

Fine needle aspiration biopsy(FNAB) is widely used in screening of head and neck(H&N) masses because it has high accuracy and few damage. The 235 cases of FNAB were performed on patient with H&N mass at the Department of Otolaryngology, Hanyang University Hospital during 1 years, from March 1985 to February 1992. The 188 of 235 were proven histologically, clinically. The results obtained were as follows ; 1) FNAB for malignant H&N mass shows sensitivity of 81.5% specificity of 96.8%. 2) FNAB for malignant LN shows sensitivity of 86.0%, specificity of 88.9%. 3) FNAB for salivary gland shows sensitivity of 66.7%, specificity 81.8%. 4) FNAB for soft tissues, bone, and intraoral lesions shows sensitivity of 90%, specificity 95.8%. 5) FNAB for tuberculosis shows false negative of 55.2%. 6) The result of FNAB was not closely related with location or size of neck nodes.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.69-72
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• 2008

EZTOMO is a crosswell seismic tomography software system. The system has capability of event picking, raytracing, inversion, error analysis, and visualization of the processing results. Waveform of the first arrival signal has been utilized to select the event of the first motion, and uncertainty measured in estimation of the first breaks has been utilized to improve the inversion process.

• The Journal of Engineering Geology
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• v.3 no.3
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• pp.231-239
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• 1993

This paper presents a result on the determination of velocity distribution by a tomographic inversion of crosshole seismic traveltimes in transversely isotropic(aniso tropic) media. The crosshole traveltimes used in this study are synthetic ones computed by ray tracing for some models having isotropic and transversely isotropic velocity distributions. The traveltimes are inverted by a general ART and ansotropic ART which considers the transversely isotropic effect during inver sion. The aniotropic ART gives accurate velodty distributions of transversely isotropic and isotropic models, while the isotropic ART determines accurate velocities only for the isotropic model but inaccurate for the transversely isotropic one. Therefore, the anisotropic ART may be used in case where no information is known on the isotropy or transverse isotropy of a survey area.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.894-902
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• 1996

Background : Tumor angiogenesis is the growth of new vessels toward and within tumor. It has been demonstrated that the growth of tumor beyond a certain size requires angiogenesis and it is closely involved in tumor progression and metastasis. The finding that intensity of neovascularization correlates independently with metastasis may lead to identification of patients in whom radical surgery should be supplemented by systemic treatment. Method : We have collected paraffin blocks of bronchoscopic biopsy of patients with non-small cell lung cancer. We highlighted the vessel by staining endothelial cell with JC70 monoclonal antibody(to CD31) immunohistochemically and counted microvessels under 200 X field using light microscopy. Results : 1) The mean microvessel count was $32.7{\pm}20.8$ (9-96) in total 29 cases. 2) There were no correlations between microvessel counts and pathologic cell type, T staging, node melastasis(N) and hematogenous metastasis(M) (p>0.05). 3) The median follow-up duration was 15 months(2-46) and there was no correlation between the microvessel counts and survival rate of lung cancer patients (p>0.05). Conclusion : Tumor angiogenesis seems to be an important prognostic factor suggesting the probability of metastasis. But the microvessel count in the bronchoscopic biopsy specimen was inadequate and very limited. There has been no data about angiogenesis of lung cancer in korea yet So the study of tumor angiogenesis using resected lung tumor specimen would be demanded.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.309-315
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• 2002

Purpose : To evaluate the result of conservative management on recurrence, survival and prognostic factors of patient with operable breast cancer. Materials and Methods : Fifty three patients, treated for localized breast cancer by lumpectomy or quadrantectomy followed by radiotherapy between January 1985 and December 1996, were retrospectively studied. All patients followed up for at least five years. Their median age was 43 years $(range\;24\~72)$. The tumor stages were as follows : T1 in 30 patients, T2 in 21, Tis in 2. Thirty-eight patients had negative and 15 had positive axillary nodes. The histological types were 42 infiltrating ductal, 2 infiltrating lobular, and 2 intraductal carcinomas with 7 other histologies. The tumor locations were the outer quadrant in 38 breasts, the inner quadrant in 13 and central in 2. Radiation doses of $46\~50\;Gy$ were given to the entire breast areas with additional doses of 14-18 Gy delivered to the tumor bed areas. Results : The overall five and 10 yea actuarial and disease free survivals were $94.3\%\;and\;92.4\%,\;91.2\%\;and\;81\%$, respectively. The overall five year survivals were $100\%$ in stage I and IIa, and $66.7\%$ in stage IIb and IIIa tumors. Seven patients failed either locally or distantly. Incidence of local failure and distant metastasis for the first failure were $7.5\%\;and\;5.7\%$, respectively. Local recurrence appeared within 2 years of treatment at the primary site and after more than 8 years outside of primary lesion, whereas distant metastasis appeared between 2 and 6 years following treatment. The overall recurrences were high at a young age (< or = 35 years), with 5 out of 12 (2 local, 3 distant), and in T2 lesions with 5 out of 21 (1 local, 3 distant, and 1 in both). Distant metastasis was high in the positive axillary lymph node group with 4 out of 15 $(26.6\%)$. A high incidence in the axillary node was noted at a young age with 7 out of 12 $(58.3\%)$ and in T2 lesions with 8 out of 21 $(38.4\%)$. A young age, positive axillary node and large tumor size were all related with poor survival. Conclusion : Based on this study, lumpectomy or quadrantectomy, followed by radiation appears to be an adequate therapeutic method in operable breast cancer. A long term follow-up is necessary because a recurrence of breast can occur long time after treatment. The poor prognostic group, especially young patients with an aggressive biological behavior needs more effective treatment modalities to improve their survival.

• Geophysics and Geophysical Exploration
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• v.14 no.2
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• pp.146-151
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• 2011

A method to evaluate and to reduce the source- and receiver- consistent noise in a cross-well travel time data was proposed. These systematic noises, which can cause some serious effects on the result of a travel time tomography, can be considered as the source and receiver statics. The method evaluates the statics through a curve-fitting of the first arrival travel times in the common source and common receiver gathers. Feasibility study was conducted on a synthetic data which simulates the cross-well travel time tomography to detect a small scale tunnel in a uniform background medium. First arrival travel times at a given source and receiver points are computed by a raytracing method, and the source consistent- and receiver consistent noises are added to the record. In case of the added noise with rms amounting to 25% of the maximum expected anomalous travel time delays, it is confirmed that the method successfully extracted the noise at the 7th step of iteration.

• Geophysics and Geophysical Exploration
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• v.14 no.2
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• pp.140-145
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• 2011

In order to analyze the influence of the noise on a cross-well traveltime tomography to detect a small scale low velocity body in a homogeneous medium, the first arrival travel times were computed one a tunnel model by a finite-difference ray tracing scheme. Three different types and four different intensity levels of white noises were added to the computed first arrival travel times, and velocity tomograms were constructed using an iterative inversion method (SIRT). Tomograms with the noise intensity up to 10% of the maximum traveltime delay in the tunnel model, showed the exact location of the tunnel. However, the velocity shown at the tunnel location was not close to air velocity but only slightly less than the velocity of the background medium. The additive random noise showed significantly less degree of influence on the resulting tomogram than the source- and receiver consistent noise.

• Geophysics and Geophysical Exploration
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• v.22 no.1
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• pp.12-20
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• 2019

The first-arrival traveltime calculation method based on the damped wave equation overcomes the shortcomings of ray-tracing methods. Since this algorithm needs to solve the damped wave equation, numerical modeling is essential. However, it is not desirable to use the finite-difference method (FDM), which has good computational efficiency, for simulating the land seismic data because of irregular topography. Thus, the finite-element method (FEM) which requires higher computational cost than FDM has been used to correctly describe the irregular topography. In this study, we computed first-arrival traveltimes in an irregular topographic model using FDM incorporating embedded boundary method (EBM) to overcome this problem. To verify the accuracy and efficiency of the proposed algorithm, we compared our results with those of FEM. As a result, the proposed method using EBM not only provided the same accuracy as the FEM but also showed the improved computational efficiency.