• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1115-1123
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• 2008

When constructing projects such as road embankments, bridge approaches, dikes or buildings on soft, compressible soils, significant settlements may occur due to the consolidation of these soils under the superimposed loads. The compressibility of the soil skeleton of a soft clay is influenced by such factors as structure and fabric, stress path, temperature and loading rate. Although it is possible to determine appropriate relations and the corresponding material parameters in the laboratory, it is well known that sample disturbance due to stress release, temperature change and moisture content change can have a profound effect on the compressibility of a clay. The early research of Tezaghi and Casagrande has had a lasting influence on our interpretation of consolidation data. The 24 hour, incremental load, oedometer test has become, more or less, the standard procedure for determining the one-dimensional, stress-strain behavior of clays. An important notion relates to the interpretation of the data is the ore-consolidation pressure ${\sigma}_p$, which is located approximately at the break in the slope on the curve. From a practical point of view, this pressure is usually viewed as corresponding to the maximum past effective stress supported by the soil. Researchers have shown, however, that the value of ${\sigma}_p$ depends on the test procedure. furthermore, owing to sampling disturbance, the results of the laboratory consolidation test must be corrected to better capture the in-situ compressibility characteristics. The corrections apply, strictly speaking, to soils where the relation between strain and effective stress is time independent. An important assumption in Terzaghi's one-dimensional theory of consolidation is that the soil skeleton behaves elastically. On the other hand, Buisman recognized that creep deformations in settlement analysis can be important. this has led to extensions to Terzaghi's theory by various investigators, including the applicant and coworkers. The main object of this study is to suggestion the modified compression index value to predict settlements by back calculating the $C_c$ from different numerical models, which are giving best prediction settlements for multi layers including very thick soft clay.

• Journal of Preventive Medicine and Public Health
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• 제45권5호
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• pp.283-290
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• 2012

Objectives: People who have chronic diseases, as well as gait imbalance or psychiatric drug use, may be susceptible to injuries from falls and slips. The purpose of this study was to evaluate the effect of musculoskeletal diseases on incidental fall-related injuries among adults in Korea. Methods: We analyzed data from the 4th Korea National Health and Nutrition Examination Survey (2007-2009), which are national data obtained by a rolling survey sampling method. The 1-year incidence of fall-related injuries was defined by health service utilization within the last year due to injury occurring after a slip and fall, and musculoskeletal diseases included osteoarthritis, rheumatoid arthritis, osteoporosis, and back pain. To evaluate the effects of preexisting musculoskeletal diseases, adults diagnosed before the last year were considered the exposed group, and adults who had never been diagnosed were the unexposed group. Results: The weighted lifetime prevalence of musculoskeletal disease was 32 540 per 100 000 persons. Musculoskeletal diseases were associated with a higher risk of fall-related injury after adjustment for sex, age, residence, household income, education, occupation, visual disturbance, paralysis due to stroke, and medication for depression (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.03 to 1.93). As the number of comorbid musculoskeletal diseases increased, the risk of fall-induced injuries increased (p-value for trend <0.001). In particular, patients who had any musculoskeletal condition were at much higher risk of recurrent fall-related injuries (OR, 6.20; 95% CI, 1.06 to 36.08). Conclusions: One must take into account the risk of fall-related injuries and provide prevention strategies among adults who have musculoskeletal diseases.

• 대한예방한의학회지
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• 제19권3호
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• pp.1-10
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• 2015

Objectives : The purpose of this study was to reveal the prevalence of Mibyeong and its symptoms including fatigue, pain, sleep disturbance, dyspepsia, depression, anxiety and anger by using the national survey. Methods : Questionnaires were collected by Gallup Korea. Participants were chosen through stratified sampling method based on area, gender and age. Questionnaire was designated to confirm the recognition, managing of Mibyeong, investigation of life habit, medical history, basic information, QoL questionnaires (Short Form-12, EuroQol-5D) and understanding of Mibyeong medical service conditions. Generally all questionnaires were used for survey the Mibyeong status in public except QoL questionnaires. Questionnaires were fulfilled by professional surveyor as face to face interview. Descriptives was used for data analysis and the results were expressed as percentage ratios (%) Results : 1,101 of people were acquired in this study. Eighty point two (80.2%) percent of participants did not know the concept of Mibyeong accurately even though 80.6% complained of Mibyeong related symptoms. Among them, fatigue was accounted for the highest response (70.7%)in this study. Sixty point four percent of participants identified non-smoking, stop drinking, eating habits and sleeping habits as a way to manage their Mibyeong related symptoms. In addition, exercising (60.8%), visiting medical institution (58.4%) and taking health functional food (52.7%) were presented. Only 23.1% among people with symptoms Mibyeong visited medical facilities. Moreover, the quality of life was found to be significantly correlated with health status. Conclusions : This study could contribute to express the importance of announcing the concept of Mibyeong and status to Korean public. Moreover, more Mibyeong studies should be conducted in the future to evaluate the Mibyeong status objectively.

• 조명전기설비학회논문지
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• 제15권6호
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• pp.65-72
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• 2001

본 논문에서는 UPS용 인버터의 강인한 디지털제어를 위하여 인버터 출력측 LC필터의 커패시터 전압과 전류의 2중 제어루프로 구성된 새로운 제어기법을 제안한다. 제안된 전압·전류의 2중 제어루프는 전압 제어루프의 커패시터 전압을 전류 제어루프의 커패시터 전류의 위상중심으로 두고, 2중 데드비트 제어를 수행함으로써 커패시터 전류의 위상지연이 보상된 완전한 진상전류 제어가 가능하게 된다. 전류 제어루프는 디지털 제어기의 시간 지연요소를 시스템의 고유한 파라미터로 가정한 2차 데드비트 제어기로 설계하여 디지털 제어기의 고유한 연산 지연시간에 의한 성능저하를 개선한다. 또한, 외란에 의한 데드비트 제어의 영향을 제거하기 위하여 부하전류 예측기법을 전류 제어루프에 부가하여 외란을 피드포워드 보상함으로써 외란에 강인한 전류제어를 수행한다.

• 한국멀티미디어학회논문지
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• 제17권2호
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• pp.124-131
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• 2014

본 논문에서는 4-채널 전위계 센서의 배열을 이용한 비접촉 제스처 인식 알고리즘을 제안한다. 주변의 전기장 변화에 민감한 전위계 센서를 스마트기기의 제스처인식에 활용하기 위해서 실내 환경에서 극저주파 대역 EMI(Electro Magnetic Interference) 및 PLN(Power Line Noise) 영향을 최소화하였다. AC 형태의 입력 데이터 값에 10Hz LPF(Low Pass Filter) 및 H/W 샘플링 속도를 고려한 최대 버퍼 값 추출 알고리즘을 적용하여 선형적인 DC 형태의 데이터로 변형한다. 추가적으로 칼만 필터를 적용함으로써 노이즈를 최소화하며, 센서간의 배열을 고려한 데이터 차분 과정을 통해 목표물의 2차원적 움직임 정보를 추출한다. 추출된 데이터 값과 peak 값의 시차정보를 이용하여 DTW(Dynamic Time Warping) 제스처 인식 및 보정 알고리즘을 구현하였으며, 다섯가지 동작 시나리오 테스트 결과 95% 이상의 높은 인식률을 보였다.

• 한국패류학회지
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• 제30권3호
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• pp.259-271
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• 2014

This study was conducted to investigate the impact of sand addition to an intertidal for the development of the Manila clam habitat on benthic community structure. For this, we focused on the spatio-temporal changes in the surface sediment condition and benthic community structure including Manila clam before and after the event. Study site was the lower part of Ojjeom tidal flat in Gonam-myeon, Taean-gun where sand added to on July 2010. We set three stations at each of sand adding area (experimental plot) and non sand-adding area (control plot) and did sampling works ten times from June 2010 to October 2011. Directly after the event, surface sediments changed to very coarse sand, but the state was not maintained over two months because of seasonal sedimentation and finally got back to the original grain sizes in eight months. The number of species and density were temporarily reduced right after the event and polychaetes such as Sternaspis scutata, Ampharete arctica were most negatively affected by the event. However, the number of species and density quickly recovered from the reduction in four to six weeks owing to the recolonization by the existing species and species in the vicinity of the plot. However, despite the recovery of ecological indies, species composition was continuously changed from one to another, thereby community structure stayed unstable condition, especially in some stations with finer sediment in their original condition. After sand addition, density of Manila clam was prominently increased at only one station with coarser sediment in its original condition.

• 대한장애인치과학회지
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• 제2권1호
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• pp.10-16
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• 2006

The aim of the present study was to investigate the dental caries experience in disabled people according to the handicapped types in Korea. This study subjects based on the national disabled survey 2004 were collected by designed cluster sampling and interviewed with structured questionnaire in order to examine dental caries and sociodemographic status. The subjects were attending the special schools and private or public welfare institutions for crippled disorder, encephalopathy disorder, mental retardation, visual disturbance, and hearing defect. Oral examination was conducted by 13 trained dentists. 1,307 of handicapped people were finally analysed. ANOVA and Cochran-Mantel-Hanzel analysis were adapted for statistical analysis. The results were as follows; Dental caries prevalence, DMFT(Decayed, missing, filled teeth), and DMFS(Decayed, missing, filled surfaces) of disabled people were higher in crippled disorder and mental retardation than the others. There were significant differences in dental caries prevalence, DMFT, and DMFS according to the disabled. DMFT was significantly higher than national population in every age group except in 12-14 year-old and more than 35 group. It was likely that the experience level of dental caries was significantly different according to the handicapped types in Korea and higher than the people without handicap.

• Journal of Ecology and Environment
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• 제44권2호
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• pp.90-97
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• 2020

Background: Natural forests are generally considered to be less prone to biological invasions than other modified ecosystems, particularly when canopy cover is high. Few decades of management of degraded forests by local communities in Nepal has increased canopy cover and altered disturbance regimes. These changes might have reduced the abundance of invasive alien plant species (IAPS) in forests. To understand the status of IAPS in such forests, we studied two community managed Shorea robusta forests (Sundari and Dhusheri) of Nawalpur district in central Nepal. In these two forests, vegetation sampling was done using circular plots 10 m radius at forest edge, gaps, and within canopy. Variation of IAPS richness and cover across these microhabitats were compared, and their variation with tree canopy cover and basal area analyzed. Result: Altogether 14 IAPS were recorded in the study forests; among them Chromolaena odorata, Ageratum houstonianum, and Lantana camara had the highest frequency. Mikania micrantha was at the early stage of colonization in Sundari Community Forest (CF) but absent in Dhuseri CF. Both IAPS cover and richness was higher at forest edge and gap than in canopy plots and both these attributes declined with increasing canopy cover and tree basal area. Conclusion: The results indicate that increase in canopy cover and closure of forest gaps through participatory management of degraded forests can prevent plant invasions and suppress the growth of previously established IAPS in Shorea robusta forests of Nepal. This is the unacknowledged benefit of participatory forest management in Nepal.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권1호
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• pp.70-79
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• 2016

This paper proposes a low-power range-scaled 14b 30 MS/s pipeline-SAR composite ADC for high-performance CIS applications. The SAR ADC is employed in the first stage to alleviate a sampling-time mismatch as observed in the conventional SHA-free architecture. A range-scaling technique processes a wide input range of 3.0VP-P without thick-gate-oxide transistors under a 1.8 V supply voltage. The first- and second-stage MDACs share a single amplifier to reduce power consumption and chip area. Moreover, two separate reference voltage drivers for the first-stage SAR ADC and the remaining pipeline stages reduce a reference voltage disturbance caused by the high-speed switching noise from the SAR ADC. The measured DNL and INL of the prototype ADC in a $0.18{\mu}m$ CMOS are within 0.88 LSB and 3.28 LSB, respectively. The ADC shows a maximum SNDR of 65.4 dB and SFDR of 78.9 dB at 30 MS/s, respectively. The ADC with an active die area of $1.43mm^2$ consumes 20.5 mW at a 1.8 V supply voltage and 30 MS/s, which corresponds to a figure-of-merit (FOM) of 0.45 pJ/conversion-step.

• Tuberculosis and Respiratory Diseases
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• 제46권5호
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• pp.723-728
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• 1999

Pulmonary embolism from metallic mercury is rare. It may occur after a deliberate intravenous injection of mercury as a suicide gesture, in the presence of drug abuse or severe psychiatric disturbance, with the hope of increasing athletic and sexual performance, and accidentally during right heart catheterization while sampling blood with mercury containing syringes. We have experienced the first case of pulmonary embolism associated with intravenous mercury injection in Korea. The blood mercury level remain elevated within the toxic range to date. This may be due to the continued absorption of embolized mercury. Multifocal areas of patchy perfusion defects are in both upper lung fields on perfusion scan of lung. Few of the abnormalities of respiratory or renal function reported previously were demonstrated. We report the case of a young male patient presenting with a clinical picture of pulmonary embolism, in whom widespread deposit of metallic mercury were demonstrated throughout both lungs and elsewhere in the body.