• 대한환경공학회지
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• 제37권1호
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• pp.45-51
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• 2015

폴리브롬화 디페닐에테르는 강한 소수성과 큰 분자량을 지닌 물질로 수체에 쉽게 용존되지 않으며, 이로 인해 다른 환경매체에 비해 수환경에 대한 연구는 많지 않다. 그러나 하 폐수처리장으로부터 수환경으로의 질량부하, 침적토에서의 재부유 현상 그리고 부유 입자 및 콜로이드로부터의 분배현상은 무시할 수 없는 영향을 미칠 것이다. 따라서 수환경 중 폴리브롬화 디페닐에테르를 조사하는 것은 중요하면서도 어려운 작업이다. 최근에 수환경에서 소수성물질을 모니터링 할 때의 어려움을 극복하기 위한 방안으로 반투과성막장비와 같은 수동적 시료채취 기법이 사용되고 있다. 수동적 시료채취를 사용하면 시료채취 기간 동안 주변환경인자의 변동을 조절하며 미량으로 존재하는 폴리브롬화 디페닐에테르를 검출하고 장기간에 거쳐 재현성 있는 모니터링 결과를 얻을 수 있다. 따라서 본 연구에서는 반투과성막장비(SPMD)를 수질 모니터링 장비로서 활용하는 가능성을 확인하고자 하였다. 강둑에서 그랩, 혼합 시료채취법과 SPMD를 적용하여 다양한 수질시료 채취기법에 따른 시간적 변동과 농도 차이를 확인하고 SPMD를 사용하여 폴리브롬화 디페닐에테르의 수환경 중 농도를 예측할 수 있는지 평가하였다.

• 한국해양공학회지
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• 제24권1호
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• pp.166-171
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• 2010

In this paper, the front-end of a digital receiver with a 25 kHz carrier frequency, 5 kHz symbol rate, and any excess-bandwidth is designed using two basic facts. The first is known as the uniform sampling theorem, which states that the sampled sequence might not suffer from aliasing even if its sampling rate is lower than the Nyquist sampling rate if the analog signal is a bandpass one. The other fact is that if the sampling rate is 4 times the center frequency of the sampled sequence, the front-end processing complexity can be dramatically reduced due to the half of the sampled sequence to be multiplied by zero in the demixing process. Furthermore, the designed front-end is simplified by introducing sub-filters and sub-sampling sequences. The designed front-end is composed of an A/D converter, which takes samples of a bandpass filtered signal at a 20 kHz rate; a serial-to-parallel converter, which converts a sampled bandpass sequence to 4 parallel sub-sample sequences; 4 sub-filter blocks, which act as a frequency shifter and lowpass filter for a complex sequence; 4 synchronized switches; and 2 adders. The designed front-end dramatically reduces the computational complexity by more than 50% for frequency shifting and lowpass filtering operations since a conventional front-end requires a frequency shifting and two lowpass filtering operations to get one lowpass complex sample, while the proposed front-end requires only four filtering operation to get four lowpass complex samples, which is equivalent to one filtering operation for one sample.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4971-4975
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• 2015

Background: Several methods have been presented for the evaluation of the endometrium in patients with abnormal uterine bleeding, which include minimal invasive and invasive approaches such as diagnostic curettage or endometrial biopsy by Pipelle. Many studies have been performed in order to compare two methods; diagnostic curettage and outpatient endometrial biopsy. This investigation compared sampling adequacy, endometrial histopathology, failure rates, duration and costs between diagnostic curettage in a hospital and endometrial biopsy. Materials and Methods: This single blind clinical trial was performed on 130 patients older than 35 years who was referred to Amir training hospital in 2013 for elective diagnostic curettage because of abnormal uterine bleeding. For all patients eligible for the study, an endometrial sample by Pipelle was taken without anesthesia or dilatation. Then under general anesthesia diagnostic curettage was performed by sharp curette. Sampling duration was calculated and both samples were sent to the same pathologist. The diagnostic values of two methods in the diagnosis of normal endometrium, endometrial hyperplasia and carcinoma were compared. The costs of these two methods were also compared. Data analysis was performed by SPSS (version 16.0) software. Chi-Square, Fisher, and Pearson tests were used and were considered statistically significant at P values less than 0.05. Results: Two methods were agreed upon 88% of sampling adequacy and 94% of pathological results. Specificity of 100% and sensitivity of 90% for detection of proliferative endometrium, secretory endometrium, simple hyperplasia without atypia and 100% for cancer were recorded. Pipelle diagnostic accuracy in comparison with curettage, have been reported over 97%, so the failure rate in this study was below 5%. Sensitivity of Pipelle for detection of atrophic endometrium was reported below 50%. Duration and cost was lower in Pipelle versus curettage. Conclusions: It is concluded that due to high agreement and cohesion coefficient between curettage and Pipelle on the issue of sampling adequacy, histopathology finding (except atrophic endometrium), low failure rate, duration of sampling and cost, Pipelle can be introduced as a suitable alternative of diagnostic curettage.

• 분석과학
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• 제18권4호
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• pp.338-343
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• 2005

본 연구에서는 실온조건에서 황성분의 채취에 사용하는 두 가지 백 방식의 시료회수율을 비교 분석하였다. 이를 위해, 가스-타잇 주사기 내부에서 원표준시료를 희석하여 검량선을 작성하였다. 그리고 이에 대비하여 테들러 백이나 플리에스터 백으로 희석한 표준시료를 이용하여 검량선을 확보하였다. 가스타잇 주사기로 확보한 검량선과 백으로 확보한 검량선의 기울기를 비교하는 방식으로 백방식의 시료 손실 또는 회수율을 비교분석한 결과, 테들러 백의 경우 평균 87%의 회수율, 폴리에스터 백의 경우 평균 77% 수준의 회수율이 관측되었다. 결과적으로 백방식으로 시료를 채취할 경우, 시료의 손실이 확인되었다. 따라서 백방식의 현장시료 채취를 할 경우, 시료의 손실에 대한 가능성을 염두에 두고 이와 관련된 여러 가지 인자들을 동시에 검정하는 것이 중요하다고 결론지을 수 있다.

• 한국산업보건학회지
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• 제25권2호
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• pp.194-201
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• 2015

Objectives: The purpose of this study is to assess the exposure level to dust and airborne microorganisms among employed workers in a clothing shopping center. Materials and Methods: On-site investigation of a clothing shopping center was performed between October and November 2012. The hazardous substances measured in this study are particulate matter(Total dust, respirable dust) and airborne microorganisms (Total airborne bacteria, total airborne fungi). Results: The highest geometric mean levels of particulate matter(total dust, respirable dust) for personal sampling were $1.735(SD:0.883)mg/m^3$ for total dust and $0.0711(SD:0.008)mg/m^3$ for respirable dust, respectively. Those for area sampling were $0.625(SD:0.091)mg/m^3$ for total dust and $0.0718(SD:0.012)mg/m^3$ for respirable dust, respectively. The highest geometric averaged concentrations of airborne microorganisms(Total airborne bacteria, total airborne fungi) were detected at $1,181(SD:105)cfu/m^3$ for total airborne bacteria and $683(SD:114)cfu/m^3$ for total airborne fungi, respectively. Concentrations of particulate matters and airborne microorganism in clothes shopping center did not correlate significantly with environmental factors such as temperature or relative humidity. Conclusions: Exposure levelshave not been established for service workers. Thus, health risk assessment for this group is very difficult. Health guidelines for service workers should be established as soon as possible.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1655-1658
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• 2004

In this paper, we design and implement remote servo motor control system with real-time micro embedded operating system. The system, where controller and camera image grabber are mounted, handles control commands transmitted from a remote PC web browser. A hard real-time servo motor driver running on the real-time micro embedded OS and then a digital control application which confirms precise sampling time intervals is constructed. Frame grabber images transmitted from camera are saved in a image data format to view on remote PC web browser.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 추계 학술대회지
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• pp.225-226
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• 2000

• Journal of Power Electronics
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• 제11권3호
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• pp.304-310
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• 2011

The power series approximation method is proposed for real time implementations of a discrete flux observer. The proposed method improves the performance of the discrete flux observer in the case of a low sampling rate and high speed range, where the simple discrete flux observer converted by the Euler method cannot estimate the actual flux precisely. The performance of discrete flux observers with different orders of approximation is compared to find out the proper order of approximation. The validity of the proposed method is verified through simulation and experiment.

• 한국환경보건학회지
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• 제41권6호
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• pp.369-379
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• 2015

Objectives: The lack of reliable information on environmental pollution and health impacts related to asbestos contamination from abandoned mines has drawn attention to the need for a community health study. This study was performed to evaluate asbestos-related health symptoms among residents near abandoned asbestos mines located in the Chungcheong Provinces. In addition, exposure assessment for asbestos is needed although the exposure to asbestos was in the past. Methods: Past exposure to asbestos among inhabitants near abandoned asbestos mines was estimated by using surface sampling of deposited dust in indoor and outdoor residences. A total of 54 participants were divided into two groups with (34 cases) and without (20 controls) diseases related to asbestos. Surface sampling of deposited dust was carried out in indoor and outdoor residences by collecting 105 samples. Deposited dust for sampling was analyzed by polarization microscope (PLM) and scanning electron microscope?energy dispersive x-ray spectrometer (SEM-EDX) to detect asbestos. Subsequently, the elements of the deposited dust with asbestos were analyzed by SEM-EDX to assess the contribution of sources such as abandoned mines, slate and soil. Results: Among the 105 samples, asbestos was detected by PLM in 29 (27.6%) sampling points, and detected by SEM in 56 (48.6%) sampling points. Asbestos in indoor residences was detected by PLM in four sampling points, and by SEM in 12 sampling points. Asbestos detection in indoor residences may be due to ventilation between indoors and outdoors, and indicates long-term exposure. The asbestos detection rate for outdoor residences in the case group was higher than that in the control group. This can be explained as the case group having had higher exposure to asbestos, and there has been continuous exposure to asbestos in the control group as well as the case group. Conclusion: Past residential asbestos exposure may be associated with asbestosis among local residents near abandoned asbestos mines. Odds ratios were calculated for asbestos detection in outdoor residence by logistic regression analysis. Odds ratio between asbestos detection and asbestosis pulmonum was 3.36 (95% CI 0.90-12.53) (p=0.072), adjusting for age, sex, smoking status and work history with multi-variable logistic regression by PLM analysis method.

• 한국습지학회지
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• 제20권4호
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• pp.314-321
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• 2018

비점오염원을 정량화하기 위해 국립환경과학원의 강우유출수 조사방법은 복합토지이용 유역 모니터링 방법으로 유출 초기 24시간동안은 1시간간격으로 채수 하는 것을 제안하였다. 그러나 고빈도 샘플링은 현장 및 분석 인력 및 비용이 과다해질 수 있다. 따라서, 본 연구는 1시간 간격 샘플링 방식에 비해 더 긴 샘플링 간격이 부하 추정에 미치는 영향을 조사하기 위해 풍영정천 유역을 토지이용현황에 따라 농촌 소유역, 도시 소유역, 유역말단으로 구분하여 채수 1시간간격과 다른 채수 시간간격에 따른 부하량의 차이를 비교하였다. BOD와 T-P는 4시간 간격까지는 부하량의 차이가 통계적으로 유의하지 않았지만, 1시간 간격 채수에 따른 부하량과 다른 채수간격 부하량의 차이가 10% 이하가 합리적이라고 판단 할 때 BOD와 T-P 모두 3시간 간격의 채수가 적합한 것으로 나타났다. 본 연구 결과는 효과적인 모니터링 체계를 구축하는데 활용될 수 있을 것으로 판단된다.