• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.3
• /
• pp.272-278
• /
• 2017

Purpose: The aim of the present prospective clinical study was to assess the cumulative survival rate (CSR) of Neobiotech implants restored with fixed partial prosthesis in relation to its potential risk factors. Materials and methods: Thirty six partially edentulous patients received Neobiotech implants and implant supported fixed partial prosthesis at Korea University Guro Hospital Dental Center from November 2009 until November 2011. The observation period was set from the implant placement and the last clinical visit until December 2015. Implant survival rate was determined using the Kaplan-Meier method. The relationship between implant survival rate and the potential risk factors were analysed using the multi Cox proportional analysis (P<.05). Results: A total of 69 implants were placed in 36 patients after a mean observation period of 45.9 months. Two out of 69 implants failed before loading, yielding a 5-year cumulative survival rate of 97.1%. The maxillary implants have a lesser CSR than the mandibular implants based on log rank test analysis (maxilla=91.3%; mandible=100% P<.05). However, the multi Cox proportional analysis showed that implant location has no significant correlation with implant failure (P>.05). Conclusion: Neobiotech implants showed predictable results with a 5 year cumulative survival rate of 97.1%.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.31 no.1
• /
• pp.10-19
• /
• 2015

Purpose: The aim of the present study was to evaluate the long-term survival of implants retrospectively and determine the risk factors associated with implant failure. Materials and Methods: Of all implants that were placed at the Department of Periodontology of the Dental Hospital of Gangneung-Wonju National University from January 1998 to December 2012, 2265 implants that were followed up until June 2013 were included in this study. Data were collected from clinical and radiographic examinations from previous visits. The information gathered included gender, age, smoking status, implant diameter, implant length, surface of implant, location of implant within the dental arch, surgical techniques and existence of complications. Results: The survival rate before loading was 98.9%. The cumulative survival rate after 5 years of loading was 97.2%, and after 15 years of loading was 95.2%. In a simple logistic regression analysis, gender (P = 0.016), smoking status (P = 0.001), location of implant (P = 0.020) and existence of complications (P = 0.002) were statistically associated with implant failure and included in the multiple regression analysis. As a result of multiple logistic regression analysis, the variables statistically associated with implant failure (P < 0.05) were smoking status (P = 0.049) and existence of complications (P < 0.001). Conclusion: The cumulative survival rate of dental implants after 15 years of loading was 95.2% and that the variables statistically associated with implant failure were smoking status and existence of complications.

• Horticultural Science & Technology
• /
• v.35 no.4
• /
• pp.393-401
• /
• 2017

One-year old pear (Pyrus pyrifolia L.) trees of a new commercial cultivar 'Manpungbae', recently developed in South Korea, were planted in 2001 (planting year 1) and trained to four trellis systems: Y-trellis, Y-II-trellis, pergola, and vase-pergola. To evaluate training systems in the local area (southern Korea), tree growth responses were compared for each trellis system from planting years 3 to 8. For trees trained to Y-trellis and pergola systems, a high proportion of land covered by tree canopy was maintained over the study duration, with 70-80% coverage in year 8. Eight-year cumulative yield per tree was increased in the vase-pergola system with a low planting density and an additional scaffold. Compared with other systems, cummulative yield use efficiency was greatest in Y-II-trellis and pergola systems in years 5 and 8. Compared with Y-II-trellis and vase-pergola systems, the 8-year cumulative yield per hectare was two fold greater for trees trained to the Y-trellis (103 tons) and pergola systems (101 tons). Use of the pergola system improved average fruit weight and fruit soluble solid contents, as well as net income in year 8. Given that we observed reduced fruit productivity and increased labor hours (pruning and orchard work), we consider the Y-trellis and pergola systems to be less valuable trellis systems than the others evaluated.

• Journal of Environmental Impact Assessment
• /
• v.26 no.1
• /
• pp.68-77
• /
• 2017

In order to estimate the non-point pollution loads from each watersheds among 209 watersheds, the calibration and validation of HSPF model were carried out based on 2012 in 2013 years. In the case of flow rate, R2 of calibration and validation were 0.71~0.93 and 0.71~0.79, which were relatively good values. With the respect to calibration of water quality, % differences between measured and simulated values were 0.4 ~ 9.7 of DO, BOD 0.5 ~ 30.2% and TN 1.9~28.6% except for Hwhangkang B site. In case of validation, DO was 0.2 ~ 13.7%, BOD 1.3~23% and TN 0.5~24.3% excluding Hwhangkang B. However, since the concentration of TP was very small compared with other items, the range of difference was large as 0.8~55.3%. level. As the result of calculating annual accumulative BOD loads for each watershed, it was found that RCH 123 (Uryeong, Gyeongsangnamdo), RCH 121 (Jinju, Gyeongsangnamdo) and RCH 92 (Daegu) were the high ranked. The unit watersheds including various landuse type susch as forest and agricultural sites in mainstream areas have a higher BOD nonpoint pollution load than those in dam regions. However, the results of the annual cumulative loading of the basins for nutrients did not appear to be consistent with the BOD annual cumulative loading ranks. Other factors that represent watershed characteristics such as landslope and soiltypes, including landuse pattern, have been found to be closely related to nonpoint pollutant loads.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.4
• /
• pp.36-43
• /
• 2011

The forward collision of vehicles in high speed can cause a chain collisions and high fatality rate. Most of the forward collisions are caused by insufficient braking distance due to detection time of driver and safe distance. Also, accumulated detection time of driver is cause of chain collisions after the forward collision. The FVCWS prevents the forward collision by maintaining the safety distance inter-vehicle and reducing detection time of driver. However the FVCWS can cause chain collisions because the system that interacts only forward vehicle has accumulated detection time of driver. In this paper, we analyze forward and chain collisions of normal vehicles and FVCWS vehicles on static traveling scenario. And then, we analyze and compare V2V based FVCWS with them after explaining the system. The V2V FVCWS reduces detection time of driver alike FVCWS as well as remove accumulated detection time of driver by broadcasting emergence message to backward vehicles at the same time. Therefore, the system decrease possibility of forward and chain collisions. All backward normal vehicles and 3~4 backward FVCWS vehicles have possibility of forward and chain collisions in result of analysis. However V2V FVCWS vehicles almost do not chain collisions in the result.

• Journal of Digital Convergence
• /
• v.11 no.11
• /
• pp.545-551
• /
• 2013

This study aimed to compare the effects of microcurrent stimulation and rest on the fatigue index by applying both to subjects who had accumulated fatigue after performing short-duration physical activity. The experiment was performed at S University from December 2012 to February 2013, on 22 healthy men in their 20s, who were right-handed, and without peripheral or musculoskeletal diseases. All subjects lifted a 10-kg box lift and lower 100 times in 15 minutes. Immediately after that, muscle fatigue index (Median Frequency: MF) and blood fatigue index (Creatine Kinase Lactate: CK, Lactate Dehydrogenase: LDH) were measured by using surface electromyography. The subjects were divided into two groups, and microcurrent stimulation and rest were mediated to the experimental and control groups, respectively, for 20 minutes. After intervention, muscle fatigue index and blood fatigue index were measured and the changes in the accumulated fatigue index were compared. Both groups manifested significantly decreased cumulative fatigue after applying the mediation compared to the pre-intervention level (p < .05), the only exception being the fatigue index of the left erector spinae in the rest group. Compared to the rest group, the microcurrent stimulation group showed a significant decrease in muscle fatigue index (p < .05) but no significant differences were found in the blood fatigue index. Given the results of this study, microcurrent stimulation is considered to be helpful in muscle fatigue recovery for workers who have to perform repetitive movements lifting weights, and additional studies on the correlations of the fatigue recovery with respect to the long-term follow-up of fatigue index and mediation time are necessary.

• The Korean Journal of Financial Management
• /
• v.23 no.2
• /
• pp.27-56
• /
• 2006

This paper analyzes whether corporations which have done capital reduction fulfill the objectives of their capital reduction as planned and also asks how did the capital reduced corporations fare in terms of stock returns, by investigating the capital reduced corporations on the Exchange and the Kosdaq between 2000 and 2004. Most capital reduced companies aim to improve their capital structure. Debt to Equity ratio among financial ratios has improved significantly after capital reduction, yet the profitability of corporations wasn't up to expectations. The analysis of cumulative abnormal returns (CARs) indicates that the CARs were below '0' during whole investigation period. Besides, the CARs of companies listed on the Kosdaq have plummeted to -53.5%. Half of the companies on the Kosdaq in this sample which have reduced their capital to avoid delisting have been eventually delisted after capital reduction. This Study concludes that simple capital reduction without having value-added projects is not beneficial to shareholders.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.648-648
• /
• 2015

이 연구는 수자원 환경을 전반적으로 객관화, 계량화하는 새로운 방법이 성공적임을 소개한다. 기존의 계량법이 일강수량, 월 강수량, 년 강수량 등등, 단순한 수학적 합계에 치중한 결과 가중 중요한 강수의 시간 분포를 간과하였다. 이 단점을 해결하여, 1) 구체적으로 매 시간, 매일 남아 있다고 추정되는 물의 양 만을 합산하는 방법을 택했다. 시간적 감소함수를 이용하여, 강수 후 유출과 증발 등으로 사라지는 물의 양을 고려한 것이다. 2) 합산기간을 객관화하였다. 기본 합산 기간을 365일로 하고, 물 부족 또는 물 과잉이 지속될 경우는 지속되는 기간만큼, 합산기간을 늘이는 방법을 택했다. 따라서 다른 지수들이 임의로 3개월 또는 12개월 등등으로 기간을 결정하는 단점을 해결했다. 이렇게 계산되는 4차원 강수지수(4-Dimensional Rain Index, 4RI)는 1) 일별유효강수지수 (AWRI), 2) 일별가뭄지수(EDI), 3) 일별 홍수지수(FI), 4) 시간별 장기 물지수(LWI), 5) 시간별 단기 물지수(SWI) 등 5개가 기본지수이다. AWRI는 매일 남아 있는 물의 양이다. 이로 인해, 전 지구의 수자원과 재해위험의 시공간적 분포의 정량화 분석이 정밀해졌다. 지구상에서 물 집중이 가장 강한 곳은 캄보디아 내의 한 지점이며 시기는 7월 말이고, 가장 약한 곳은 사하라 사막의 한 지역임이 확인되었다. 또 한국에서 발생하는 갈수기와 풍수기가 정의되었고, 이들의 각 지역별 특성과 차이가 정량적으로 드러났다. 시간적 분포 또한 명확하게 드러나, 각종 저수지의 물 관리나 농?임산물의 생산관리에 획기적 전환점이 마련되었다. 각 국가별로, 각 지역별로 이런 분석은 향후도 무수히 시도되어야 할 것이다. EDI는 매일의 AWRI를 그 날짜의 평균치와 비교한 값이다. 장기가뭄 및 단기가뭄의 강도를 모두 가장 정밀하게 표현한다. FI는 일별로 홍수, 산사태, 침수, 토사 (이하 홍수 등이라 칭함)의 위험을, LWI는 장기 누적된 강수량에 의한 돌발적 홍수 등의 위험을, SWI는 단기 누적된 강수량에 의한 돌발적 홍수 등의 위험을 잘 반영한다. 이들은 모두 시간적으로 산발적인 호우에 의한 홍수 등의 위험을 한 개의 지수로 표현해 주는 장점이 있다. 강수 후 홍수가 발생하기 까지는 시간차이가 있기 때문에, 특히 호우 경보에는 SWI가, 홍수 경보에는 LWI가 아주 효과적이다. 결론적으로 5개의 4차원 강수지수는 물환경의 시공간적 분포진단과 예측, 그리고 조기경보에 혁명적 진화를 초래함이 확인되었다. 따라서 추후 모든 강수기후와 연관된 연구는 연강수량 등의 단순 합산보다, 4차원 강수지수를 먼저 사용하는 것이 바람직 할 것임이 제안되었다.

• Journal of the Daesoon Academy of Sciences
• /
• v.48
• /
• pp.407-443
• /
• 2024

The relationship between finance, natural disasters and epidemics, the Liang Province Rebellion of mostly Qiang ethnic groups, and the occurrence of displaced persons in the Later Han Dynasty, is examined in this article. Also explored is the financial crisis that had started accumulating in the Later Han Dynasty, as well as the Yellow Turban Rebellion and the displacement of the people. It is argued in this research that the financial crisis had an influence on the occurrence. The Yellow Turban Rebellion began in 184, seventeenth year of Lingdi's reign. The rebellion was an incident that occurred due to a complex combination of natural calamities and man-made disasters. Various natural disasters during the Lingdi period, poor measures for immigration, and Lingdi's refusal to accept Yangci and Liu Tao's advice that the immigrants should return home were the direct causes of the Yellow Turban Rebellion. In short, the increase in military spending due to natural disasters and the Liang Province Rebellion caused financial deterioration were the direct causes of the Yellow turban rebellion. The Yellow Turban Rebellion was suppressed in less than a year. Therefore, the Yellow Turban Rebellion itself was not the cause of the collapse of the Later Han Dynasty. It was rather case that the great fire in South Palace in Luoyang, the capital of Later Han Dynasty, in 185, the increase in taxes of 10 qian per mu (畝) to rebuild the palace, the open and compulsory encouragement of the trafficking of official posts, and the exploitation of civil servants, which destabilized the population. Thereupon, rebellions broke out among the people in various places. Therefore, unlike the Yellow Turban Rebellion, the collapse of the Later Han Dynasty should be viewed as primarily the result of man-made calamities rather than natural disasters.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.6
• /
• pp.817-825
• /
• 1999

Background : Forceps biopsy, bronchial brushing, and bronchial washing are used in conjunction with bronchoscopy to provide specimens for histologic and cytologic analysis in patients with suspected lung cancer. This study was performed to evaluate how many times brushing should be done and how much fluid should be used during bronchial washing for increasing diagnostic yield, and to evaluate which combination of these procedures gives the highest diagnostic yield. Methods : Forty patients, with suspected lung cancer, who had bronchoscopically visible lesions were enrolled in this prospective study. During one bronchoscopic examination four forceps biopsies, four bronchial brushings, and bronchial washing were done in all patients. The patients were divided into four groups by the amount of normal saline used for bronchial washing; group I, 10 ml ; group II, 20ml ; group III 30ml, and group IV, 40ml. We analyzed the results in 36 patients confirmed as lung cancer. Results : The diagnostic sensitivity of bronchial washing before and after forceps biopsy and bronchial brushing were 36% and 28%, respectively. The cumulative diagnostic sensitivity of bronchial washing was 47% and significantly higher than that of bronchial washing before or after forceps biopsy and bronchial brushing (p<0.05). The diagnostic sensitivity of bronchial washing with saline of 30ml was significantly higher than that of bronchial washing with saline of 10ml or 20ml (p<0.05). The diagnostic sensitivity of the first brushing was 75%, the second brushing 78%, the third brushing 83%, and the fourth brushing 67%. With repeated brushing up to three times, the diagnostic sensitivity increased to 92% (p<0.05). However, inclusion of the fourth brushing did not give a further increase of the diagnostic sensitivity. The diagnostic sensitivity of forceps biopsy was 86%. The diagnostic sensitivities of forceps biopsy by the type of bronchial lesion were as follows: tumor, 88%; infiltration, 67%; infiltration with nodularity, 80%; and collapse, 100%. The combination of forceps biopsy and bronchial washing gave a diagnostic sensitivity of 89%. The diagnostic sensitivity of combining forceps biopsy with bronchial brushing was 97%. Addition of bronchial washing did not increase the diagnostic yield over forceps biopsy and bronchial brushing. Conclusion : In patients with central lung cancer, forceps biopsies and repeated brushings up to three times should be done for maximal diagnostic yield.