• 한국측량학회지
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• 제21권2호
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• pp.147-154
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• 2003

근거리 수치사진측량은 카메라의 취급이 비교적 간단하고 카메라의 노출점을 임의로 결정하여 카메라와 대상물의 관계를 자유로이 조정할 수 있으므로 소규모지역 또는 지상의 대상물을 측정하는데 효과적으로 이용될 수 있다. 이에, 본 연구에서는 휴대가 간편하고 수치영상의 자체 저장능력을 가진 디지털 카메라를 이용하여 촬영조건의 다양한 변화에 따른 위치오차를 분석하며, 광속 조정을 통하여 높은 정확도의 부화소 좌표를 획득하여 3차원 모니터링을 위한 기초 자료와 근거리 수치 사진측량기법의 국부지역모형생성의 활용방안을 모색하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.465-469
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• 2006

In recent years there has been considerable interest in the construction of super high-rise buildings. From the prior art, various procedures and devices for surveys during and after the phase of erection of a high-rise building are known. High-rise buildings are subject to strong external tilt effects caused, for instance, by wind pressures, unilateral thermal effects by exposure to sunlight, and unilateral loads. Such effects are a particular challenge in the phase of construction of a high-rise building, in as much as the high-rise building under construction is also subject to tilt effects, and will at least temporarily lose its - as a rule exactly vertical - alignment. Yet construction should progress in such a way that the building is aligned as planned, and particularly so in the vertical, when returning into an un-tilted basic state.It is essential that a straight element be constructed that theoretically, even when moving around its design centre point due to varying loads, would have an exactly vertical alignment when all biasing conditions are neutralised. Because of differential raft settlement, differential concrete shortening, and construction tolerances, this ideal situation will rarely be achieved. This paper describes a procedure developed by the authors using GPS observations combined with a network of precision inclination sensor to provide reliable coordinated points at the top of the worldwide highest-rise building under construction in Dubai.

• Journal of Preventive Medicine and Public Health
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• 제56권4호
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• pp.368-376
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• 2023

Objectives: Recent research indicates a potential association between workplace violence and an increased risk of cardiovascular disease (CVD) in the working-age population. However, the relevant evidence in the United States is sparse. Thus, this study was conducted to explore the possible relationship between workplace violence and CVD among United States workers. Methods: We utilized cross-sectional data from the 2015 National Health Interview Survey, which included a representative sample of 18 380 workers, to investigate the associations between workplace violence and the prevalence of CVD using logistic regression. Workplace violence was determined based on self-reported threats, bullying, or harassment at work over the past 12 months, supplemented with additional information regarding frequency. CVD included all forms of heart disease and stroke. Results: A total of 1334 workers reported experiences of workplace violence, and 1336 workers were diagnosed with CVD. After adjustment for covariates, participants who reported any instance of workplace violence had significantly higher odds of having CVD (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.35 to 2.30) than those who reported no such violence. Furthermore, the highest odds of CVD (OR, 1.80; 95% CI, 1.23 to 2.63) were observed among those frequently exposed to workplace violence. Even occasional exposure to workplace violence was associated with 74% excess odds of CVD. Conclusions: Our study indicates an association between workplace violence and CVD in United States workers, exhibiting a dose-response pattern.

• 한국환경보건학회지
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• 제36권5호
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• pp.402-410
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• 2010

The objectives of this study were to evaluate the air quality surrounding an indoor swimming pool, to estimate the cancer risk based on the airborne exposure to trihalomethanes (THMs), and to examine the ventilation efficiency by Computational Fluid Dynamics (CFD). Chlorine and THMs were measured poolside, and in the staff room and reception area. The indoor swimming pool was modeled using the Airpak program, with ventilation drawings and actual survey data. Temperature, flow and mean age of the air were analyzed. Levels of chlorine poolside, and in the staff room, and reception area were $203\;{\mu}g/m^3$, $5\;{\mu}g/m^3$, and $10\;{\mu}g/m^3$, respectively. Chloroform was the dominant THM in all sampling sites and mean concentrations were $16.30\;{\mu}g/m^3$, $0.51\;{\mu}g/m^3$, and $0.06\;{\mu}g/m^3$ poolside, in the staff room and reception area, respectively. Bromodichloromethane and Dibromochloromethane levels were respectively estimated as $10.3\;{\mu}g/m^3$ and $1.7\;{\mu}g/m^3$ poolside, $1.3\;{\mu}g/m^3$ and $0.1\;{\mu}g/m^3$ in the staff room, and were not detected in the reception area. The cancer risks from inhalation exposure to THMs were estimated between $3.37{\times}10^{-7}$ and $1.84{\times}10^{-5}$. A short circulation phenomenon was observed from the supply air vents to the exhaust air vents located in the ceiling. A high temperature layer was formed within one meter of the ceiling, and a low temperature layer was formed under this layer due to the low velocity and high temperature of the supply air, and the improper locations of the supply air vents and exhaust air vents. The stagnation was evident at the above adult pool and the mean age of the air was 22 minutes. Disinfection by-products in the indoor swimming pool were present in higher concentrations than in the outdoor air. In order to increase the removal of pollutants, adjustment was required of the supply air volume and the supply/exhaust position.

• 한국산업보건학회지
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• 제20권1호
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• pp.19-28
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• 2010

This study was designed to investigate the effect of increased blood and tibia lead on the change of bone mineral density in retired male lead workers. One hundred nine retired male lead workers who worked in 4 different lead industries and 51 nonoccupationally lead exposed male subjects were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured by broadband ultrasound attenuation(BUA) at left calcaneous bone area with broadband ultrasound attenuation method of QUS-2(Metra Biosystems Inc, USA). Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.711) and these two variables were negatively correlated with BUA in bivariate analysis. BUA and tibia lead showed significant main effects on the change of blood lead after adjusting covariates. The effect modification by the level of BMD (low: lower than the median of BUA and high: higher than the median of BUA) was observed between the association of tibia lead and blood lead after adjustment of covariates. The subjects who had higher BMD seemed to have lower blood lead by the increase of tibia lead than those of lower BMD. In the multiple regression analysis of blood lead and tibia lead on BUA after adjustment of covariates, only blood lead showed statistically significant effect on BUA. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.

• 한국콘텐츠학회논문지
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• 제9권6호
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• pp.256-265
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• 2009

레이저 출력은 20w에서 100w까지 연속적으로 조절이 되고 노출시간은 0.01초에서 수초 사이로 조절이 가능 하다. 펄스동작은 레이저 빔을 주기적으로 차단할 수가 있고 슈퍼펄스는 0.1$\sim$1ms사이에서 방전을 이루어지며, 순간적인 레이저 출력은 5$\sim$10 까지 증가된다. 특히, 자궁암의 경우 자궁구 내벽에서 악성세포를 제거해야 하므로 펄스에 대한 튜브출력의 안정이 매우 중요하다. 따라서, 본 연구에서는 영전압 스위칭동작을 확보하여 컨버터 1 차측 주 회로에 고주파 변압기 누설인덕턴스($L_1$) 증가 및 직렬 인덕터 없이 안정된 소프트 스위칭 동작영역이 확보, 인덕터($L_f$)전류의 순환전류 경로차단 컨버터 1차측 주회로 스위칭소자와 고주파 변압기의 도통손실이 크게 줄어, 고주파 2차측 정류부($D_5,\;D_6$)도 소프트 스위칭 되고, 스위칭손실 흡수분을 부하로 회생할 수 있는 특징을 갖고, 튜브안정화가 되어 설계 및 제작하여 실험한 결과, 기존장비에 비해 10%의 향상된 결과를 가져왔고, 추후 시스템적으로 보완을 하면 우수한 결과가 될 것으로 사려 된다.

• Korean Journal of Radiology
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• 제24권7호
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• pp.681-689
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• 2023

Objective: Three-dimensional rotational angiography (3D-RA) is increasingly used for the evaluation of intracranial aneurysms (IAs); however, radiation exposure to the lens is a concern. We investigated the effect of head off-centering by adjusting table height on the lens dose during 3D-RA and its feasibility in patient examination. Materials and Methods: The effect of head off-centering during 3D-RA on the lens radiation dose at various table heights was investigated using a RANDO head phantom (Alderson Research Labs). We prospectively enrolled 20 patients (58.0 ± 9.4 years) with IAs who were scheduled to undergo bilateral 3D-RA. In all patients' 3D-RA, the lens dose-reduction protocol involving elevation of the examination table was applied to one internal carotid artery, and the conventional protocol was applied to the other. The lens dose was measured using photoluminescent glass dosimeters (GD-352M, AGC Techno Glass Co., LTD), and radiation dose metrics were compared between the two protocols. Image quality was quantitatively analyzed using source images for image noise, signal-to-noise ratio, and contrast-to-noise ratio. Additionally, three reviewers qualitatively assessed the image quality using a five-point Likert scale. Results: The phantom study showed that the lens dose was reduced by an average of 38% per 1 cm increase in table height. In the patient study, the dose-reduction protocol (elevating the table height by an average of 2.3 cm) led to an 83% reduction in the median dose from 4.65 mGy to 0.79 mGy (P < 0.001). There were no significant differences between dose-reduction and conventional protocols in the kerma area product (7.34 vs. 7.40 Gy·cm², P = 0.892), air kerma (75.7 vs. 75.1 mGy, P = 0.872), and image quality. Conclusion: The lens radiation dose was significantly affected by table height adjustment during 3D-RA. Intentional head off-centering by elevation of the table is a simple and effective way to reduce the lens dose in clinical practice.

• Journal of Nutrition and Health
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• 제45권4호
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• pp.347-361
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• 2012

Limited studies are available concerning the effect of heavy metal exposure on cardiovascular diseases. As environmental pollution increases, food contamination, including heavy metal contamination of fish, also increases. However, researches based on the intake of heavy metals, cardiovascular disease, and fish intakes are inconclusive. We assessed an association of heavy metal exposure with cardiovascular disease and fish intake in a nationally representative group of general Korean adults. We used data from the combined 2008-2010 Korean National Health and Nutrition Examination Survey (KNHANES), and analyzed the data of 5,139 Koreans who participated in KNHANES. All participants were older than 20 years, and were diagnosed with stroke, ischemic heart disease, or hypertension. The mean blood cadmium, lead concentration, and mercury concentration of subjects were $1.07{\pm}0.01{\mu}g/L$, $2.49{\pm}0.02{\mu}g/dL$, and $5.19{\pm}0.08{\mu}g/L$, respectively. We used the survey logistic regression model to account for the complex sample design of the cardiovascular disease risk in order to estimate the odds ratios (OR). After adjusting for age, education, income, alcohol, smoking, and BMI, the increase of serum cadmium in blood was associated with the increase in the prevalence of hypertension. Further, the increase in blood cadmium concentration was associated with the increase of both systolic blood pressure (SBP) and diastolic blood pressure (DBP). Although higher fish intakes were significantly associated with higher blood mercury concentration (p for trend < 0.0001), fish intakes did not affect either blood cadmium or lead concentration. Comparing the highest fish intake group with the lowest intake group, the OR of hypertension was 0.31 (95% CI: 0.19-0.59) in the crude model for total fish. However, these associations were no longer significant after the adjustment for potential confounding factors. In conclusion, cadmium in blood was associated with an increased risk of hypertension in the general Korean adult population. However, we found no evidence of a clear relationship between cardiovascular disease and frequency of fish consumption.

• 한국산업보건학회지
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• 제11권1호
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• pp.56-69
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• 2001

Objectives : This study was designed to develop and standardize a checklist for ergonomic risk factors, and to provide ergonomic guidelines for managing cumulative trauma disorders (CTDs) in automobile assembly lines. Methods : The Checklist for Ergonomic Risk Factors (CERF-1) was developed based on the results of previous studies, and then modified after performing pilot study. Information on the symptoms possibly related with CTDs was obtained using a self-reported Questionnaire from 465 automobile assembly workers. Their job conditions were examined to assess risk factors through both direct observation and video analysis. Results : Rate of detecting risky job through CERF-1 was 85.6%, and was similar to that (88.8%) by Occupational Safety and Health Adminstration(OSHA) checklist but higher than that (63.7%) by American National Standards Institute(ANSI) Z-365. Relationship of the exposure scores derived from CERF-1 with levels of symptom was greater (r=0.49) than OSHA (r=0.28) and ANSI Z-365 (r=0.22). Considering the relationship, jobs scoring higher than 16 could be classified as the Risk Job. and lower than 16 as the Low Risk Job. Sensitivity and specificity of the Risk Job were 92.5 % and 31.5 %, respectively. Odds ratio (OR) after age adjustment was 5.69 (95 % confidence interval 3.15-10.29) for the Risk Job, and these ORs were significantly different from those of the Low Risk Job. The exposure scores were Quite valid, in that the scores at the main survey were significantly correlated with those at the follow-up survey, as suggested by test-retest(r=0.88) and inter-rater reliability(r=0.80). Conclusions : The CERF-1, developed in this study, will be an efficient tool for evaluation of risk jobs for CTDs in automobile assembly lines, and can be used easily by health care providers.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.437-444
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• 2009

Purpose: Transgender is a disorder of gender identity, who have appropriate chromosomal, hormonal and anatomical characteristics corresponding to their sexual phenotype but feel strongly with respect to their sexual identity, that they belong to the opposite sex. There is a persistence discomfort and sense of inappropriateness about one's assigned sex in a person who has reached puberty. Transgender is a psychiatric problem, but surgical method provides more satisfactory adjustment for patients. In gender reassignment surgery for female to male transgender, mastectomy, nipple reduction, hysterectomy, oophorectomy and phalloplasty are included. And as the final operation, recommended for scrotoplasty and artificial testes insertion. So we investigated the necessity and method of scrotoplasty in the final operation of female to male transgender. Method: The authors have long term follow-up of 75 cases female to male transgender during January, 1991 to February, 2008. Among them, 13 cases were evaluated in this study. During phalloplasty, the labium major skin preserved. And this labium majoral skin flap was made for the neoscrotum. At least six months later, artificial testes were inserted in neoscrotum with local anesthesia. Middle sized (3 cm diameter) artificial testes(silicon gel or carving soft silicone implant) were used because of the limitation of the neoscrotum. We evaluated the questionnaire and interview about the postoperative satisfaction in configuration of reconstructed scrotum, and the necessity of operation, the postoperative psychosocioeconomic improvement and limitation of body exposure activities such as swimming, public bathing. Results: Based on this study, satisfaction of reconstructed scrotum after scrotoplasty was improved(92%). The necessity of scrotoplasty was in 92.3% and the postoperative psychosocioeconomic well - being improvement was 77% in answers. Less limitation of activities requiring body exposure was 54% in answers. Most of the patients were satisfied with the results of surgical operation inspite of the operative procedure had some postoperative complications. Conclusion: This study was reported that the scrotoplasty in female to male transgender is not only a conversion of external genitalia but also an improvement of psychosocial state. Most patients sincerely hope to this operation, so we improve our surgical method for more good results.