• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.2
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• pp.81-92
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• 2001

According to analyses of high-resolution seismic profiles (air gun, sparker, and SBP) and a deep-drill core(YSDP 105) in the mid-eastern Yellow Sea, stratigraphic and geoacoustic models have been established and seismo-acoustic modeling has been fulfilled using ray tracing of finite element method. Stratigraphic model reflects seismo-, litho-, and chrono-stratigraphic sequences formed under a significant influence of Quaternary glacio-eustatic sea-level fluctuations. Each sequence consists of terrestrial to very-shallow-marine coarse-grained lowstand systems tract and tidal fine-grained transgressive to highstand systems tract. Based on mean grain-size data (121 samples) of the drill core, bulk density and P-wave velocity of depositional units have been inferred and extrapolated down to a depth of the recovery using the Hamilton's regression equations. As goo-acoustic parameters, the 121 pairs of bulk density and P-wave velocity have been averaged on each unit of the stratigraphic model. As a result of computer ray-tracing simulation of the subsurface strata, we have found that there are complex ray paths and many acoustic-shadow zones owing to the presence of irregular layer boundaries and low-velocity layers.

• Tuberculosis and Respiratory Diseases
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• v.55 no.2
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• pp.140-153
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• 2003

Background : The cell-mediated immune reaction to tuberculosis infection involves a complex network of cytokines. The extent of inflammation, tissue damage and severity of the disease suggested to be determined by the balance between extent and duration of the proinflammatory cytokine response versus those of the suppressive cytokines. The systemic cytokine response in pathogenesis of tuberculosis can be assessed by measuring serum cytokine levels. Method : Serum interleukin-1 beta(IL-$1{\beta}$), IL-2, IL-4, IL-6, IL-10, IL-12(p40), tumor necrosis factor-alpha(TNF-${\alpha}$), interferon-gamma(IFN-${\gamma}$) and transforming growth factor-beta(TGF-${\beta}$) levels were measured in 83 patients with pulmonary tuberculosis, 10 patients with endobronchial tuberculosis before treatment and 20 healthy subjects by using a sandwich ELISA. In patients with pulmonary tuberculosis, they were divided into mild, moderate and far advanced group according to the severity by ATS guidelines. To compare with those of pretreatment levels, we measured serum IL-$1{\beta}$, IL-2, IL-4, IL-6, IL-10, IL-12(p40), TNF-${\alpha}$, IFN-${\gamma}$ and TGF-${\beta}$ levels in 45 of 83 patients with pulmonary tuberculosis after 2 and 6 months of treatment. Results : 1) In sera of patients with active pulmonary tuberculosis(n=83), IL-$1{\beta}$, IL-6(p<0.05), TNF-${\alpha}$, and IFN-${\gamma}$ were elevated and TGF-${\beta}$ was decreased comparing to control. IL-2, Il-12(p40), IL-4 and IL-10 were similar between the patients with tuberculosis and control. 2) In endobronchial tuberculosis, IL-6 and TNF-${\alpha}$ were elevated and TGF-${\beta}$ was decreased comparing to control. IL-12(p40) seemed to be elevated comparing to pulmonary tuberculosis. 3) Far advanced tuberculosis showed markedly elevated IL-6 and IFN-${\gamma}$ level(p<0.05). 4) The significant correlations were noted between IL-1, IL-6 AND TNF-${\alpha}$ and between IL-12, Il-2 and IL-4(p<0.01). 5) After 2 and 6 months of standard treatment, the level of IL-6 and IFN-${\gamma}$ was significantly decreased(p<0.05). Conclusion : These results showed that an altered balance between cytokines is likely to be involved in the extent of inflammation, tissue damage and severity of the disease tuberculosis. But, it should be considered diversities of cytokine response according to type of tuberculosis and immunity in clinical application and interpreting future studies.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.1
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• pp.9-17
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• 2014

Purpose: The purpose of this study was to compare zirconia implants with titanium implants from the view point of biomechanical stability and histologic response on osseointegration when those were placed with xenograft materials. Materials and methods: Specimens were divided into two groups; the control group was experimented with eighteen titanium implants which had anodized surface and the experimental group was experimented with eighteen sandblasted zirconia (Y-TZP) implants. At the tibias of six pigs, implants were installed into bone defect sites prepared surgically and treated with resorbable membranes and bovine bone. Two pigs were sacrificed after 1, 4 and 12 weeks respectively. Each implant site was sampled and processed for histologic and histomorphometric analysis. The stability of implants was evaluated with a $Periotest^{(R)}$. And the interfaces between bone and the implant were observed with a scanning electron microscope. Results: In stability analysis there was no significant difference between Periotest values of the control group and the experimental group. In histologic analysis with a light microscope after 4 weeks, there was new bone formation with the resorption of bovine bone and the active synthesis of osteoblasts in both groups. In bone-implant contact percentage there was significant difference between both groups (P<.05). In bone area percentage there was no significant difference between both groups. In analysis of both groups with a scanning electron microscope there was a gap between bone and a surface at 4 weeks and it was filled up with bone formed newly at 12 weeks. Conclusion: When accompanied by xenograft using membrane, bone to implant contact percentage of zirconia implants used in this experiment was significantly less than that of the titanium implants by surface treatment of anodic oxidation. So, it is considered that the improvement of zirconia implant is needed through ongoing research on surface treatment methods for its practical use.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.291-301
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• 1998

Purpose : A retrospective study was conducted comparing single daily fraction (SDF) thoracic radiotherapy (TRT) with twice daily (BID) TRT to determine the potential benefit of BID TRT in limited-stage small cell lung cancer (SCLC). Endpoints of the study were response. survival, pattern of failure, and acute toxicity. Materials and Methods : Between November 1989 to December 1996, 78 patients with histologically proven limited-stage SCLC were treated at the Department of Therapeutic Radiology, Chungnam National University Hospital. Of these, 9 were irradiated for palliative intent, and 1 had recurrent disease. Remaining 68 patients were enrolled in this study. There were 26 patients with a median age of 58 years, and 22 (85$\%$) ECOG performance score of less than 1 in SDF TRT. There were 42 patients with a median age of 57 years, and 36 (86$\%$) ECOG performance score of less than 1 in BID TRT By radiation fractionation regimen, there were 26 in SDF TRT and 42 in BID TRT. SDF TRT consisted of 180 cGy, 5 days a week. BID TRT consisted of 150 cGy BID, 5 days a week in 13 of 42 and 120 cGy BID, in 29 of 42. And the twice daily fractions were separated by at least 4 hours. Total radiotherapy doses were between 5040 and 6940 cGy (median, 5040 cGy) in SDF TRT and was between 4320 and 5100 cGy (median, 4560 cGy) in BID TRT. Prophylactic cranial irradiation (PCI) was recommended for patients who achieved a CR. The recommended PCI dose was 2500 cGy/10 fractions. Chemotherapy consisted of CAV (cytoxan 1000 mg/$m^2$, adriamycin 40 mg/$m^2$, vincristine 1 mg/$m^2$) alternating with VPP (cisplatin 60 mg/$m^2$, etoposide 100 mg/$m^2$) every 3 weeks in 25 (96$\%$) of SDF TRT and in 40 (95$\%$) of BID TRT. Median cycle of chemotherapy was six in both group. Timing for chemotherapy was sequential in 23 of SDF TRT and in 3 BID TRT, and concurrent in 3 of SDF TRT and in 39 of BID TRT Follow-up ranged from 2 to 99 months (median, 14 months) in both groups. Results : Of the 26 SDF TRT, 9 (35$\%$) achieved a complete response (CR) and 14 (54$\%$) experienced a partial response (PR). Of the 42 BID TRT, 18 (43$\%$) achieved a CR and 23 (55$\%$) experienced a PR. There was no significant response difference between the two arms (p=0.119). Overall median and 2-year survival were 15 months and 26.8$\%$, respectively. The 2-year survivals were 26.9$\%$ and 28$\%$ in both arm, respectively (p=0.51). The 2-rear survivals were 35$\%$ in CR and 24.2$\%$ in PR, respectively. The grade 2 to 3 esophageal toxicities and grade 2 to 4 neutropenias were more common in BID TRT (p=0.028 0.003). There was no difference in locoregional and distant metastasis between the two arms (p=0 125 and 0.335, respectively). The most common site of distant metastasis was the brain. Conclusion : The median survival and 2-year survival were 17 months and 20.9$\%$ in SDF TRT with sequential chemotherapy, and 15 months and 28$\%$ in BID TRT with concurrent chemotherapy, respectively. We did not observe a substantial improvement of long-term survival in the BID TRT with concurrent chemotherapy compared with standard schedules of SDF TRT with sequential chemotherapy. The grade 2 to 3 esophageal toxicities and glade 2 to 4 neutropenias were more common in BID TRT with concurrent chemotherapy. Although the acute toxicities were more common in BID TRT with concurrent chemotherapy than SDF TRT with sequential chemotherapy, a concurrent chemotherapy and twice daily TRT was feasible. However further patient accrual and long-term follow up are needed to determine the potential benefits of BID TRT in limited-stage SCLC.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Radiation Oncology Journal
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• v.27 no.2
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• pp.55-63
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• 2009

Purpose: This study was performed to objectively evaluate the rate of tumor response to hypofractionated radiotherapy for advanced squamous cell carcinomas of the head and neck. Materials and Methods: Thirty-one patients with advanced squamous cell carcinoma of the head and neck, who were treated by hypofractionated radiotherapy with 3 Gy per fraction for palliative purpose between 1998 and 2008, were reviewed retrospectively. Every tumor-volume was measured and evaluated from CT (computed tomography) images obtained before and 2~3 months after radiotherapy. The radiation toxicity was assessed during and after radiotherapy. A statistical analysis was performed to investigate overall survival, progressionfree survival, and the prognostic factors for survival and response. Results: The median age of the study patients was 70 years. In addition, 85% of the patients were in stage 4 cancer and 66.7% had an ECOG performance status of 1~2. The mean tumor-volume was 128.4 cc. Radiotherapy was administered with a total dose of 24~45 Gy (median: 36 Gy) over 10~25 days. Twenty-nine patients were treated with 30 Gy or more. The observed complete response rate was 12.9% and the partial response rate was 61.3%. Median survival time was 8.9 months and the 1-year progression-free survival rate was 12.9%. The treatment response rate was confirmed as a prognostic factor in the rate of survival. The primary site, stage, tumor-volume, radiotherapy field and overall radiation-dose showed a significant relationship with survival and treatment response. No grade 4 toxicity was observed during and after radiotherapy. Conclusion: There was an objective tumor-regression in about 74% of patients treated by hypofractionated radiotherapy. Further evaluation is needed to select the appropriate fraction-size and patient who may require the additional radiotherapy.

• Journal of Hospice and Palliative Care
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• v.16 no.4
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• pp.205-215
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• 2013

Most terminally ill cancer patients experience various physical and psychological symptoms during their illness. In addition to pain, they commonly suffer from fatigue, anorexia-cachexia syndrome, nausea, vomiting and dyspnea. In this paper, I reviewed some of the common non-pain symptoms in terminally ill cancer patients, based on the National Comprehensive Cancer Network (NCCN) guidelines to better understand and treat cancer patients. Cancer-related fatigue (CRF) is a common symptom in terminally ill cancer patients. There are reversible causes of fatigue, which include anemia, sleep disturbance, malnutrition, pain, depression and anxiety, medical comorbidities, hyperthyroidism and hypogonadism. Energy conservation and education are recommended as central management for CRF. Corticosteroid and psychostimulants can be used as well. The anorexia and cachexia syndrome has reversible causes and should be managed. It includes stomatitis, constipation and uncontrolled severe symptoms such as pain or dyspnea, delirium, nausea/vomiting, depression and gastroparesis. To manage the syndrome, it is important to provide emotional support and inform the patient and family of the natural history of the disease. Megesteol acetate, dronabinol and corticosteroid can be helpful. Nausea and vomiting will occur by potentially reversible causes including drug consumption, uremia, infection, anxiety, constipation, gastric irritation and proximal gastrointestinal obstruction. Metoclopramide, haloperidol, olanzapine and ondansetron can be used to manage nausea and vomiting. Dyspnea is common even in terminally ill cancer patients without lung disease. Opioids are effective for symptomatic management of dyspnea. To improve the quality of life for terminally ill cancer patients, we should try to ameliorate these symptoms by paying more attention to patients and understanding of management principles.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.453-473
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• 1992

Background: National survey was performed to estimate the incidence of sarcoidosis in Korea. The clinical data of confirmed cases were analysed for the practice of primary care physicians and pulmonary specialists. Methods: The period of study was from January 1991 to December 1992. Data were retrospectively collected by correspondence with physicians in departments of internal medicine, dermatology, ophthalmology and neurology of the hospitals having more than 100 beds using returning postcards. In confirmed and suspicious cases of sardoidosis, case record chart for clinical and laboratory findings were obtained in detail. Results: 1) Postcards were sent to 523 departments in 213 hospitals. Internal medicine composed 41%, dermatology 20%, ophthalmology 20% and neurology 19%. 2) Postcards were returned from 241 departments (replying rates was 48%). 3) There were 113 confirmed cases from 50 departments and 10 cases. The cases were composed from internal medicine (81%), dermatology (13%), ophthalmology (3%) and neurology (3%). 78 confirmed cases were analysed, which were composed from department of internal medicine (92%), dermatology (5%), and neurology (3%). 4) The time span for analysed cases was 1980 to 1992. one case was analysed in 1980 and the number gradually increased to 18 cases in 1991. 5) The majority of patients (84.4%) were in the age group of 20 to 49 years. 6) The ratio of male to female was 1 : 1.5. 7) The most common chief complains were respiratory symptoms, dermatologic symptoms, generalized discomforts, visual changes, arthralgia, abdominal pains, and swallowing difficulties in order. 16% of the patients were asymptomatic. 8) Mean duration between symptom onset and diagnosis was 2 months. 9) The most common symptoms were respiratory, general, dermatologic, ophthalmologic, neurologic and cardiac origin in order. 10) Hemoglobin, hematocrits and platelet were in normal range. 58% of the patients had lymphopenia measuring less than 30% of white cell count. The ratio of CD4 to CD8 lymphocytes was $1.73{\pm}1.16$ with range of 0.43 to 4.62. ESR was elevated in 43% of the cases. 11) Blood chemistry was normal in most cases. Serum angiotensin converting enzyme (S-ACE) was $66.8{\pm}58.6\;U/L$ with the range of 8.79 to 265 U /L. Proteinuria of more than 150 mg was found in 42. 9% of the patients. 12) Serum IgG was elevated in 43.5%, IgA in 45.5%, IgM in 59.1% and IgE in 46.7%. The levels of complement C3 and C4 were in the normal range. Anti-nuclear antibody was detected in 11% of the cases. Kweim test was performed in 3 cases, and in all cases the result was positive. 13) FVC was decreased in 17.3%, FEV1 in 11.5%, FEV1/FVC in 10%, TLC in 15.2%, and DLco in 64.7%. 14) PaO2 was decreased below 90 mmHg in 48.6% and PaCO2 was increased above 45 mmHg in 5.7%. 15) The percentage of macrophages in BAL fluid was $51.4{\pm}19.2%$, lymphocytes $44.4{\pm}21.1%$, and the ratio of CD4 to CD8 lymphocytes was $3.41{\pm}2.07$. 16) There was no difference in laboratory findings between male and female. 17) Hilar enlargement on chest PA was present in 87.9% (bilaterally in 78.8% and unilaterally in 9.1%). 18) According to Siltzbach's classification, stage 0 was 5%, stage 158.3%, stage 228.3%, and stage 38.3%. 19) Hilart enlargement on chest CT was present in 92.6% (bilaterally 76.4% and unilaterally in 16.2%). 20) HRCT was done in 16 cases. The most common findings were nodules, interlobular thickening, focal patchy infiltrations in order. Two cases was normal finding. 21) Other radiologic examinations showed bone change in one case and splenomegaly in two cases. 22) Gallium scan was done in 12 cases. Radioactivity was increased in hilar and mediastinal lymph nodes in 8 cases and in parenchyme in 2 cases. 23) The pathologic diagnosis was commonly performed by transbrochial lung biopsy (TBLB, 47.3%), skin and mediastinal lymph nodes biopsy (34.5%), peripheral lymph nodes biopsy (23.6%), open lung biopsy (18.2%) and bronchial biopsy in order. 24) The most common findings in pathology were non·caseating granuloma (100%), multi-nucleated giant cell (47.3%), hyalinized acellular scar (34.5%), reticulin fibrin network (20%), inclusion body (10.9%), necrosis (9.1%), and lymphangitic distribution of granuloma (1.8%) in order. Conclusion: Clinical, laboratory, radiologic and pathologic findings were summarized. This collected data will assist in finding a test for detection and staging of sarcoidosis in Korea in near future.

• Journal of the Korean earth science society
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• v.23 no.6
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• pp.461-473
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• 2002

Concept mapping is a device for representing the conceptual structure of a subject discipline in a two dimensional form which is analogous to a road map. In the teaching and learning of earth science, each concept depends on its relationships to many others for meaning. Using concept mapping in teaching helps teachers and students to be more aware of the key concepts and relationships among them. The purpose of this study is to investigate the effect of the use of concept mapping on science achievement and the scientific attitude in ocean units of earth science. The results of this study are as follows; first, the science achievement of a group of concept mapping teaching is significantly higher than that of the group of traditional teaching. Also, when the achievement levels are compared among different cognitive ability groups, the effect is more significant in mid or lower level student groups than in high level groups. The use of concept mapping is more effective when the concepts have a distinct concept hierarchy. Second, the scores of the test of ‘attitude toward scientific inquiry’ and ‘application of scientific attitude’ of the group of concept mapping teaching are significantly higher than those of the group of traditional teaching, whereas the scores of the test of ‘interest in science learning’ of concept mapping teaching is not different from those of group of traditional teaching. Third, the survey on the use of concept mapping shows a positive response across the tested groups. The use of concept mapping is more beneficial in fostering the comprehension of the topic. A concept map of student's own construction facilitates the assessment of learning, thus promising the usefulness of concept mapping as a means of evaluation. In regard to retention aspect, concept mapping is considered to be more effective in confirming and remembering the topic, while less effective in the aspects of activity and interest. In conclusion, the use of concept maps makes learning an active meaningful process and improves student's academic achievement and scientific attitude. If the concept mapping is more effectively as an active teaching strategy, more meaningful learning will be attained.

• Journal of Korea Technology Innovation Society
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• v.10 no.1
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• pp.73-97
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• 2007

R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.