• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.17 no.3
• /
• pp.139-148
• /
• 2012

The short-term variation of salinity and temperature in a dyked estuarine environment is mainly controlled by the freshwater discharge from the dyke. We examined the distribution of salinity and temperature by the freshwater discharge in the Yeongsan River estuary using the CTD data obtained from 8 stations through three surveys in June (weak discharge) and August (intensive discharge), 2010. During the weak discharge in June, the surface salinity showed 30-32.5 psu and its horizontal gradient was relatively high around Goha-do (0.25~0.32 psu/km). On the other hand, the salinity of the bottom layer was almost constant in the range of 33 psu. Water temperature ranged $19{\sim}21^{\circ}C$ and displayed higher gradient in north-south direction than the gradient of east-west direction. During the intensive freshwater discharge on August 12, the salinity dropped to 9~26 psu. The maximum horizontal gradient of surface salinity reached 3.8 psu/km in the north of Goha-do where the strong salinity front was formed, and the horizontal salinity gradient of bottom layer was 0.28 psu/km. The horizontal gradient of water temperature was $-0.45^{\circ}C/km$ in the surface and $-0.12^{\circ}C/km$ in the bottom with high surface temperature near the dyke and decreasing gradually to the river mouth. After 3 days of the intensive discharge ($3^{rd}$ survey), the surface salinity increased to 22~26 psu. However, there still existed relatively high horizontal gradient around Goha-do. In the mean time, the bottom salinity decreased to 26.5~27.5 psu, but its gradient was not big as much as the surface gradient. According to time series of CTD profile near the dyke, the discharged fresh water jetted down temporarily and then recovered gradually with the recovering speed of 0.4 m/hour for the discharge case of $13{\times}10^6$ ton. Due to the combined effects of freshwater discharge and surface heating during the summer of 2010, the Yeongsan estuary, in general, underwent intensified vertical stratification, which in turn caused the inhibition of vertical mixing, especially inside area of estuary. Based on the spatial distribution of salinity and temperature, the Yeongsan estuary can be divided into three regions: the Goha-do area with strong horizontal gradient of salinity and temperature, inner estuary from Goha-do to the dyke with low salinity, and outer estuary from Goha-do to the coasts with relatively high salinity.

• Journal of the Korean Arthroscopy Society
• /
• v.15 no.2
• /
• pp.83-91
• /
• 2011

Purpose: Microfracture has been used as a first-line treatment to repair articular cartilage defects. In this study, a new technique using an extracelluar matrix biomembrane to cover the cartilage lesions after microfracture was evaluated in terms of cartilage repairability and clinical outcome compared with conventional microfracture technique in a prospective randomized trial. Materials and Methods: A total of 53 patients (59 cases) without osteoarthritis who had focal full thickness articular cartilage lesions were randomly assigned in two group. Seventeen patients (17 cases) underwent conventional microfracture procedure (control group) and thirty-six patients (42 cases) received microfracture and placing biomembrane cover (ArtiFilm$^{TM}$) concomitantly (experimental group). Clinical assessment was done through 6 months postoperatively using the subjective International Knee Documentation Committee IKDC questionnaire, and visual analog scale (VAS) for pain and satisfaction. Magnetic resonance imaging (MRI) was performed at 6 months after the operation in all patients. Results: In clinical outcomes, the significant difference was observed between both groups in IKDC, but not in VAS for pain and for satisfaction (final outcomes of IKDC, p=0.001; VAS for pain, p=0.074; VAS for satisfaction, p=0.194). The MRI showed good to complete defect fill (67 to 100%) in 33 patients (78.6%) of experimental group and 4 patients (23.5%) of control group, respectively. In control group, 9 of 17 patients (52.9%) showed poor defect fill (less than 33%), whereas 5 (11.9%) in experimental group (p=0.001). Assessment of peripheral integration revealed no gap formation in 35 patients (83.3%) in experimental group and 6 patients (35.3%) in control group (p=0.001). No serious complications or adverse effects related to the biomembrane were found. Conclusion: Good short-term follow-up clinical results were obtained in the group whose cartilage defects in the knee joint were covered with biomembrane after the microfracture, with the MRI findings confirming the excellent regeneration of the defective cartilage area. This suggests that the surgery to cover the defective area with biomembrane (ArtiFilm$^{TM}$) after the microfracture procedure is a safe, more effective treatment to induce cartilage regeneration.

• Journal of the Korean Arthroscopy Society
• /
• v.11 no.2
• /
• pp.92-98
• /
• 2007

Purposes: The purpose of this study was to report surgical technique of double bundle anterior cruciate ligament(ACL) reconstruction and to compare the short-term clinical results between arthroscopic single-bundle and double-bundle ACL reconstruction. Materials and Methods: From May 2005 to May 2006, ninety-eight patients were underwent ACL reconstruction. We designed prospective study with sixty-one patients who were revealed isolated ACL injury. We serially checked clinical and radiologic data preoperatively and postoperatively. We compared single-bundle with double-bundle ACL reconstruction patients with preoperative datas and postoperatively 1-year data. There were 30 single bundle reconstruction and 31 double bundle reconstruction. Stability was assessed objectively by anterior stress radiographs with the $Telos^{(R)}$ device and the maximal manual test with the KT-2000 arthrometer. The clinical results were assessed by IKDC(International Knee Documentation Committee) and OAK(Orthopadische Arbeitsgruppe Knie) scores. Also, we evaluated postoperative thigh circumference and range of motion. All of operations were done by only one surgeon. Results: At single-bundle reconstruction group, preoperative AP instability which was checked by $Telos^{(R)}$ device and the maximal manual test with the KT-2000 arthrometer was $7.9{\pm}3.3$ and $7.4{\pm}2.0$, respectively. At double-bundle reconstruction group, it was $8.3{\pm}3.5$ and $7.9{\pm}3.2$, respectively. Residual AP laxity checked at 1 year after operation was $1.9{\pm}1.2$ and $2.2{\pm}1.6$ in single-bundle reconstruction group, and $1.1{\pm}0.9$ and $1.0{\pm}1.0$ in double-bundle reconstruction group. So, double-bundle reconstruction had better results in both anterior stress radiographs with the $Telos^{(R)}$ device and the maximal manual test with the KT-2000 arthrometer, and there were significant differences in statistics. But, clinical results such as IKDC(International Knee Documentation Committee) scores, OAK(Orthopadische Arbeitsgruppe Knie) scores, thigh circumference and range of motion had no significant difference between two groups. Conclusions: On the basis of stability, the side-to-side anterior laxity of double-bundle ACL reconstruction was significantly better than that of single-bundle reconstruction, although there were no significant differences in the other clinical measures among them.

• Journal of agricultural medicine and community health
• /
• v.27 no.1
• /
• pp.21-31
• /
• 2002

The aim of this study was to analyse and conduct the comprehensive geriatric assessment for the elderly in rural area. The subjects were 388 older people aged 65 years or older living in the community. Data for comprehensive assessment such as physical, mental, functional, social and environmental conditions were collected from January to February, 2001 through a person-to-person interview. Of the total 388 olders, 169(43.6%) were men and 219(56.4%) were women. Mean ages of men and women were $73.5{\pm}6.4$ and $74.0{\pm}6.2$ years respectively. Three common diseases of the elderly were arthralgia(51.6%), chronic back pain(33.2%) and hypertension(18.6%), and higher in women than in men. Impairment rate of vision, hearing and bowel or bladder control was 59.0%, 20.1%, and 28.4% respectively. But that of lover extremities 3.4%. In terms of cognitive function, short term memory loss was found in 33.7% of males and 44.7% of females. The percentage of fully independent in the six ADL items was 72.2% in men and 58.9% in women. In the social supportive system, 49.5% of the elderly were living with spouse, and 22.9% living alone, 26.3% having care giver. These results will provide basic data for the development of community-based health program, which gives appropriate health service for the elderly living in the community.

• Korean Journal of Ecology and Environment
• /
• v.41 no.3
• /
• pp.348-359
• /
• 2008

The objectives of the study were to elucidate functional modifications in relation to hydrological, physico-chemical and ecological aspects in Daechung Reservoir by the upper dam constructions of Youngdam Reservoir and analyze temporal and spatial dynamic patterns using trophic parameters of TN, TP, chlorophyll (CHL), and Secchi depth (SD). Hydrological data such as inflow, precipitation, and water levels before (BDC, 1995$\sim$2000) and after (ADC, 2001$\sim$2006) the dam construction showed that precipitation had greater correlations with inflow volume in the BDC (r=0.964, p=0.002) than in the ADC (r=0.857, p=0.029). This outcome indicates that the upper dam construction influenced the inflow and water level of Daechung Reservoir. One of the greatest changes after the dam construction was decreases of nutrient contents (TN, TP) and increases of algal biomass (as CHL) as the water residence time increases. Values of CHL had greater relations with TP in the ADC (r=0.412, p<0.001) than the BDC (r=0.249, p<0.001), indicating that CHL had greater response at a given phosphorus in the ADC. Thus, algal yield at a given TP (CHL : TP ratios) increased in the ADC, resulting in a greater CHL-TP relations. Long-term interannual TP, TN, SD, and CHL showed greater variations in the riverine zone (RZ) than any other transition (TZ) and lacustrine zones (LZ). This phenomenon was mainly attributed to rapid hydrological response in the riverine zone (RZ) to flow reductions (short water residence time) from the upper dam, resulting in ambient contents of nutrients and light regime along with functional relations of CHL-TP.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.19 no.3
• /
• pp.169-179
• /
• 2014

Monthly mean surface heat fluxes in the southeastern Yellow Sea are calculated using directly observed airsea variables from an ocean buoy station including short- and longwave radiations, and COARE 3.0 bulk flux algorithm. The calculated monthly mean heat fluxes are then compared with previous estimates of climatological monthly mean surface heat fluxes near the buoy location. Sea surface receives heat through net shortwave radiation ($Q_i$) and loses heat as net longwave radiation ($Q_b$), sensible heat flux ($Q_h$), and latent heat flux ($Q_e$). $Q_e$ is the largest contribution to the total heat loss of about 51 %, and $Q_b$ and $Q_h$ account for 34% and 15% of the total heat loss, respectively. Net heat flux ($Q_n$) shows maximum in May ($191.4W/m^2$) when $Q_i$ shows its annual maximum, and minimum in December ($-264.9W/m^2$) when the heat loss terms show their annual minimum values. Annual mean $Q_n$ is estimated to be $1.9W/m^2$, which is negligibly small considering instrument errors (maximum of ${\pm}19.7W/m^2$). In the previous estimates, summertime incoming radiations ($Q_i$) are underestimated by about $10{\sim}40W/m^2$, and wintertime heat losses due to $Q_e$ and $Q_h$ are overestimated by about $50W/m^2$ and $30{\sim}70W/m^2$, respectively. Consequently, as compared to $Q_n$ from the present study, the amount of net heat gain during the period of net oceanic heat gain between April and August is underestimated, while the ocean's net heat loss in winter is overestimated in other studies. The difference in $Q_n$ is as large as $70{\sim}130W/m^2$ in December and January. Analysis of long-term reanalysis product (MERRA) indicates that the difference in the monthly mean heat fluxes between the present and previous studies is not due to the temporal variability of fluxes but due to inaccurate data used for the calculation of the heat fluxes. This study suggests that caution should be exercised in using the climatological monthly mean surface heat fluxes documented previously for various research and numerical modeling purposes.

• Korean Security Journal
• /
• no.58
• /
• pp.81-106
• /
• 2019

This study analyzed safety management system against disasters perceived by local residents of Chungcheongbuk-do and then examined the policy directions to be considered in order for local governments to improve the safety level of residents and build an effective safety management system against disasters. The findings were as follows. First, in their recognition of risks of safety against disasters, recognition on the possibility of the occurrence of natural disasters was higher than that of social disasters or safety accidents. Secondly, also in the aspect of the importance of category of safety management against disasters, they recognized that of natural disasters far higher than others. Third, they showed satisfaction higher than average with basic job performance of local governments related with safety management, whereas they showed relatively less satisfaction with the aspects of check and publicity of risk factors, and short-term restoration system out of phased job performance. Fourth, in the aspect of capability of local governments for safety management against disasters, they rated positively capability of the responsible departments and the professionality, whereas they relatively underestimated the scale or budget of safety-related organizations. Fifth, the policy directions to be taken for safety against disasters by local governments included strengthening of regular education like experience-based training, expansion of education among local residents, more support for relevant facilities and resources, activation of residents-participating campaigns, improvement of apparatus and personnel treatment related with firefighting and security, frequent patrol and oversight, more exercises against disasters. So, to strengthen safety management system against disasters in local governments and build a effective responding system may need to extend programs assisting vulnerable class to safety against disasters, build a community-friendly safety management system, extend the cooperation system by participation of residents, enhance collaboration and support system with safety-related bodies like police, firefighters.

• Journal of Chest Surgery
• /
• v.35 no.11
• /
• pp.792-798
• /
• 2002

Although there is a controversy on the optimal timing for active infective endocarditis(IE), recently good results of early surgical intervention have been published. Herein, we analyzed the results of surgery for active IE according to the duration of preoperative antibiotic treatment. Material and Method : Retrospectively, we analyzed 51 patients who underwent operation for active IE at the department of thoracic and cardiovascular surgery of Samsung medical center from Mar. 1995 to Oct. 2001. Male to female ratio was 39:12, mean age of the patients was 44.5$\pm$17.8 years(range : 13~74). Infected valves were mitral valve in 17(33.3%), aortic valve in 15(29.4%), mitral and aortic valve in 12(23.5), and tricuspid valve in 5(9.8%) cases. Among them, prosthetic valve endocarditis was present in 10(19.6%) cases. Infecting organism was Staphylococcus in 19(37.3%), Streptococcus in 17(33.3%), Enterococcus in 3(5.9%), fungus in 3(5.9%), and other bacteria in 5(9.8%) cases. Organism was not isolated in 6(11.8%) cases, and two organisms were isolated in 4(7.8%) cases. Dividing these patients into two groups according to the duration of preoperative antibiotic treatment(A: less than 7 days, B: more than 8 days), we compared the surgical results between the two groups. Result : There were 16 cases in group A and 35 in group B. Annular reconstruction was performed in 10(62.5%) cases in group A and 10(28.6%) cases in group B, which has statistically significance(p＜0.05). There was one early death in group B. Forty nine patients(96.1%) except two were followed up with mean follow-up duration of 28.7 $\pm$ 23.6 months. Endocarditis was recurred in one in group A, and two in group B. Three late deaths occurred in group B. Recurrence rate and survival were not statistically different between the two groups. Conclusion : Early surgery for active IE showed good results as the result of that which was performed after prolonged antibiotic treatment; therefore, we believe that early surgery for active If could effectively eradicate the infection.

• Journal of Chest Surgery
• /
• v.34 no.9
• /
• pp.672-679
• /
• 2001

Background: Surgical correction of partial anomalous pulmonary venous connection to the superior vena cava has been associated with postoperative venous obstruction and sinus node dysfunction. In this paper we describe our current approach and its short-term results. Material and Method: Between April 1999 and January 2000, 5 consecutive patients, ranging from 2 months to 66 years old, underwent corrective operation for partial anomalous pulmonary venous connection to the superior vena cava at Sejong General Hospital and Daegu Catholic University Medical Center. Surgical correction involved diversion of the pulmonary venous drainage to the left atrium using a right atrial flap(2 patients) or prosthetic patch(3 patients) with division of the superior vena cava superior to the restore site of the pulmonary veins and reimplantation on the right atrial appendage to restore systemic venous drainage. Result: All patients were discharged between postoperative day 9 and 15 without complications. One Russian boy returned to his country, therefore, he was lost to follow-up after discharge. Remaining 4 patients were asymptomatic and in normal regular sinus rhythm at a mean follow-up of 17.75$\pm$4.27 months. Follow-up echocardiographic study (range, 12 to 24 months) revealed no incidence of narrowing of the venous pathways or of residual shunt. Conclusion: Our current approach is relatively simple and reproducible in achieving unobstructive pulmonay venous and SVC pathways. By avoiding incision across the cavoatrial junction, surgical injury to the sinus node and its artery may be minimized. The presented surgical technique can be safely and effectively applied to the selected patients.

• Journal of Chest Surgery
• /
• v.40 no.5 s.274
• /
• pp.341-350
• /
• 2007

Background: We present here the early and midterm surgical results for infective endocarditis and we especially focus on the effect of aggressive reconstruction or root implantation after wide debridement. Material and Method: Between January 1995 and Jun 2006, we enrolled 79 adult infective endocarditis patients who underwent surgical treatment. There were 63 and 16 native and prosthetic valve endocarditis cases, respectively. They included 27 cases of culture negative endocarditis. With performing valve replacement or repair, 28 of the patient underwent a more aggressive surgical option, for example, aortic root replacement or reconstruction, or heart base reconstruction etc. Result: There were statistical relationships between the in-hospital mortality and staphylococcal infection, urgent-based operation and operation during the active phase of endocarditis. Wide debridement and aggressive reconstruction were not related to either the post operative mortality or the early morbidity. Culture negative endocarditis was not related to the postoperative mortality and morbidity. Conclusion: Physicians must pay attention to patients' medical treatment during the preoperative period of the infective endocarditis. If surgery is considered for treating infective endocarditis, it should be performed before the downhill course of the disease so that the surgical outcome is improved. Wide debridement and more aggressive reconstruction are also warranted.