• 제목/요약/키워드: sampling variation

검색결과 640건 처리시간 0.029초

양산단계 군수품에 대한 정부품질보증활동 실효성 향상 방안 (Suggestions on Enhancing the Effectiveness of Government Quality Assurance Activities for Military Supplies in Production Stage)

  • 신병철;황우열;안남수;김덕환;이계림;장봉기;변재현
    • 품질경영학회지
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    • 제44권1호
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    • pp.153-166
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    • 2016
  • Purpose: Government quality assurance (QA) activities in Korea, which is carried out by the Defense Agency for Technology and Quality, is not effective due to 1) the obscureness of the QA implementation method, 2) the gap between QA activities of provisions and those conducted in the fields, and 3) the variation in subjective judgement among the QA personnel. The purpose of this paper is to propose some suggestions to enhance the effectiveness of government QA activities for military supplies in the production stage. Methods: QA activities for military supplies are investigated and problematic aspects are deduced for the production stage. To secure the effectiveness of the QA activities, Defense Contract Management Agency of the United Sates is benchmarked and five improvement methods are presented. Results: Five improvement aspects are 1) reflecting special terms and conditions of government mandatory inspection in contract, 2) classifying QA personnel, 3) making use of data collection and analysis template compulsory, 4) providing checklist for process review, and 5) establishing guidelines for sampling plans for product examination. Conclusion: Suggestions of this paper can lead to consistency and balance in government QA activities, reducing military suppliers' complaints and enhancing the effectiveness of QA effort, and ultimately contributing to the quality improvement of military supplies.

아산호의 생태학적 연구 1.이화학적 특성과 영양상태 (Ecological Studies on the Asan Reservoir. 1. Physicochemical chracteristics and Trophic Status)

  • 전상호;신윤근
    • 생태와환경
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    • 제35권3호통권99호
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    • pp.181-186
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    • 2002
  • 본 연구는 1997년 3월부터 11월가지 아산호 19개 정점에서 부영양화 정도를 평가하기 위하여 이화학적 환경요인을 조사하였다. 수온은 의 $8.3{\sim}35.3{\circ}^C$범위였고 여름철에 수온 약층이 형성되는 것으로 나왔으며 용존산소량도 같은 경향을 보였다. 투명도는 0.1~1m의 범위로 매우 낮았으며 SS는 11.3~2143.3mg/l의 범위로 강우량과 식물플랑크톤의 현존량에 의해 영향을 받는 것으로 나타났다. 영양염 농도는 지천에서 높고 하류로 갈수록 낮아지는 경향을 보였으며 계절적으로는 녹조현상이 일어난 여름과 초가을에 낮았고 초봄과 겨울에는 높았다. Carlson 의한 부양양화도 (Trophic State Index)를 가지고 판정한 아산호의 영양상태는 과영양 상태이었다.

서산지역의 대기질 경년변화 특성에 관한 연구 (A Study on the Trends of Air Quality and Characteristics in Seosan Area of Korean Penninsula)

  • 손병현;박동소
    • 한국산학기술학회논문지
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    • 제9권3호
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    • pp.779-786
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    • 2008
  • 본 연구에서는 1998년부터 2006년까지 9년 동안의 서산 지역 대기오염물질 농도 변화 특성을 조사하였다. 조사 결과, 최근 3년 동안 CO와 $O_3$을 제외한 $SO_2,\;NO_2$ 및 PM-10은 농도 변화가 거의 없는 안정화 단계를 보였다. $NO_2$, CO 및 $SO_2$의 월평균농도 변화는 여름철에 감소하다. 겨울철에 증가하는 경향을 보였으며 $O_3$과 PM-10은 봄철에 높은 농도를 보이며, 강수가 집중되는 여름철에 가장 낮은 농도분포를 보였다. 2006년 12월까지 오존의 1시간 기준치인 0.1 ppm을 초과한 횟수는 동문동이 68회, 독곶리 93회였고 8시간 기준치인 0.06 ppm을 초과한 횟수는 동문동 210회, 독곶리 213회였다. 또한 미세먼지의 경우 24시간기준인 $150{\mu}g/m^3$을 초과한 횟수가 동문동 25회, 독곶리 54회로 나타났다.

장기모니터링을 통한 지하수계의 이해 - 광릉소유역 사례 연구 (Understanding the Groundwater System through the Long-term Monitoring - a case Study of Gwangneung Headwater Catchment)

  • 이재민;우남칠
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제17권4호
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    • pp.51-62
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    • 2012
  • Effects of climate change on groundwater system requires understanding the groundwater system in temporal and spatial scales through the long-term monitoring. In this study, the spatio-temporal variations of groundwater were analyzed through the continuous observation of water level, electrical conductivity (EC) and water temperature with automatic data-loggers and sampling in a Gwangneung catchment, Korea, for the four years from 2008 to 2011. Groundwater monitoring were performed at the nest-type wells, MW1 and MW2, located in upsteam and downstream of the catchment, respectively. During the survey period, both the total amount of annual precipitation and the frequency of concentrated rainfall have increased resulting in the elevation of runoff. Water level of MW1 showed no significant fluctuations even during the rainy season, indicating the confined groundwater system. In contrast, that of MW2 showed clear seasonal changes, indicating the unconfined system. The lag-time of temperature at both wells ranged from one to three months depending on the screened depths. Results of chemical analyses indicated that major water compositions were maintained constantly, except for the EC decreases due to the dilution effect. Values of the stable-isotope ratios for oxygen and deuterium were higher at MW2 than MW1, implying the confined system at the upstream area could be locally developed.

지역별 에어로졸 화학성분 농도 및 광학특성 비교 (Comparison of the concentration characteristics and optical properties of aerosol chemical components in different regions)

  • 소윤영;송상근;최유나
    • 한국환경과학회지
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    • 제28권1호
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    • pp.107-123
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    • 2019
  • The aerosol chemical components in $PM_{2.5}$ in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) ($26{\mu}g/m^3$ and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC ($21.7Mm^{-1}$) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

Experience of nursing students about the barriers to patient education: a qualitative study in Iran

  • Abbasi, Mohammad;Rabiei, Leili;Masoudi, Reza
    • Korean journal of medical education
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    • 제30권4호
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    • pp.327-337
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    • 2018
  • Purpose: Patient education is a dynamic and continuous process that should be implemented during the entire time of hospital stay and even afterward. Studies have shown the typically poor quality of patient education in Iran and its failure to convey the required knowledge and skills to patients. The purpose of this study was to survey the experience of nursing students in regard to the challenges of patient education in hospitals. Methods: This qualitative study was conducted using the conventional qualitative content analysis approach on a sample of 21 undergraduate nursing students (4th semester and beyond), which was drawn from the Qom Nursing and Midwifery School through purposive sampling with maximum variation. Data were collected through semi-structured interviews conducted over a period of 45 to 75 minutes, and were analyzed using the conventional qualitative content analysis. Results: Results were derived from the experiences of 21 nursing students (nine males, 12 females) about the research subject. The primary themes identified in the study were the student-related, patient-related, instructor-related, education environment-related, and curriculum-related barriers to patient educations. Conclusion: Participants believed that patient education in Iranian hospitals is faced with many challenges. Nursing instructors and curriculum planners should ensure more emphasis on patient education at the initial semesters of nursing education curriculum and make sure that it is included in the evaluation of students. Hospital officials should provide a dedicated education environment with suitable facilities, tools, and atmosphere for patient education. Also, special education programs need to be developed for less educated patients.

Damage index based seismic risk generalization for concrete gravity dams considering FFDI

  • Nahar, Tahmina T.;Rahman, Md M.;Kim, Dookie
    • Structural Engineering and Mechanics
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    • 제78권1호
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    • pp.53-66
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    • 2021
  • The determination of the damage index to reveal the performance level of a structure can constitute the seismic risk generalization approach based on the parametric analysis. This study implemented this concept to one kind of civil engineering structure that is the concrete gravity dam. Different cases of the structure exhibit their individual responses, which constitute different considerations. Therefore, this approach allows the parametric study of concrete as well as soil for evaluating the seismic nature in the generalized case. To ensure that the target algorithm applicable to most of the concrete gravity dams, a very simple procedure has been considered. In order to develop a correlated algorithm (by response surface methodology; RSM) between the ground motion and the structural property, randomized sampling was adopted through a stochastic method called half-fractional central composite design. The responses in the case of fluid-foundation-dam interaction (FFDI) make it more reliable by introducing the foundation as being bounded by infinite elements. To evaluate the seismic generalization of FFDI models, incremental dynamic analysis (IDA) was carried out under the impacts of various earthquake records, which have been selected from the Pacific Earthquake Engineering Research Center data. Here, the displacement-based damage indexed fragility curves have been generated to show the variation in the seismic pattern of the dam. The responses to the sensitivity analysis of the various parameters presented here are the most effective controlling factors for the concrete gravity dam. Finally, to establish the accuracy of the proposed approach, reliable verification was adopted in this study.

Variation of Medicinal Plants Species Richness along Vertical Gradient in Makawanpur District, Nepal

  • Gaire, Damodar;Jiang, Lichun;Yadav, Vijay Kumar;Shah, Jit Narayan;Dhungana, Sunita;Upadhyaya, Anju;Manjan, Shiv Kumar;Heyojoo, Binod Kumar
    • Journal of Forest and Environmental Science
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    • 제37권2호
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    • pp.104-115
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    • 2021
  • The research attempted to analyze the medicinal plant species richness in the vertical gradient from lower to the highest elevation of Makawanpur, focusing on the relationship between species richness and elevation which is very important for conservation and management of species diversity. Inventory was carried out in the study area by taking sampling intensity of 0.5% in the effective area. Altogether, 42 sample plots were laid in the field with the help of GIS software maintaining 50 m altitude difference. High species diversity was found in the herbs species whereas shrubs have comparatively low species diversity. The maximum species richness is found in herbs and poles whereas shrubs and trees have relatively low species richness. Research showed that species richness of medicinal plants increased with altitudinal gradient. While analyzing the species richness from 350 to 2,550 m (msl), the highest species richness was received with the elevation ranges from 1,800 m to 2,300 m. There was a positive relationship between species richness and altitudinal gradient in the study area. In addition, we have recorded the high value medicinal plants after 1,800 m altitude and rarely within 1,000 m. Medicinal plants correlated both positive and negative relationships with the increased altitude. The altitudinal response has positively seen except density (n/ha) of Shrubs. Domestication and cultivation of high value medicinal plants should be promoted in community forest including private lands. Training, workshops and awareness programs should be conducted to make people aware about medicinal plants resource utilization, conservation and commercialization of available medicinal plants.

Profiling of T Cell Receptor β-Chain Complimentary Determining Regions 3 Repertoire in Subarachnoid Hemorrhage Patients Using High-Throughput Sequencing

  • Kim, Bong Jun;Ahn, Jun Hyong;Youn, Dong Hyuk;Jeon, Jin Pyeong
    • Journal of Korean Neurosurgical Society
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    • 제64권4호
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    • pp.505-513
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    • 2021
  • Objective : The adaptive immune response following subarachnoid hemorrhage (SAH) is not well understood. We evaluated and compared the T cell receptor (TCR) immune repertoire of good-grade and poor-grade SAH patients to elucidate the T cell immunology after ictus. Methods : Peripheral blood from six SAH patients was collected at two different times, admission and at the 7-day follow-up. Composition and variation of the TCR β-chain (TCRB) complimentary determining regions (CDR) 3 repertoire was examined using high-throughput sequencing; the analysis was based on sampling time and disease severity (good vs. poor-grade SAH). Results : Clonality at admission and follow-up were 0.059 (0.037-0.038) and 0.027 (0.014-0.082) (median, 25th-75th percentile). Poor-grade SAH (0.025 [0.011-0.038]) was associated with significantly lower clonality than good-grade SAH (0.095 [0.079-0.101]). Poor-grade SAH patients had higher diversity scores than good-grade SAH patients. CDR length was shorter in good-grade SAH vs. poor-grade SAH. Differences in clonotype distribution were more prominent in TCRBV gene segments than TCRBJ segments. TCRBV19-01/TCRBJ02-04 and TCRBV28-01/TCRBJ02-04 were the most increased and the most decreased V-J pairs in the 7-day follow-up compared to admission in good-grade SAH. The most increased and decreased V-J pairs in poor-grade SAH patients were TCRBV28-01/TCRBJ02-06 and TCRBV30-01/TCRBJ02-04, respectively. Conclusion : The TCRB repertoire is dynamic in nature following SAH. TCRB repertoire may facilitate our understanding of adaptive immune response according to SAH severity.

Comparison of Machine Learning-Based Radioisotope Identifiers for Plastic Scintillation Detector

  • Jeon, Byoungil;Kim, Jongyul;Yu, Yonggyun;Moon, Myungkook
    • Journal of Radiation Protection and Research
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    • 제46권4호
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    • pp.204-212
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    • 2021
  • Background: Identification of radioisotopes for plastic scintillation detectors is challenging because their spectra have poor energy resolutions and lack photo peaks. To overcome this weakness, many researchers have conducted radioisotope identification studies using machine learning algorithms; however, the effect of data normalization on radioisotope identification has not been addressed yet. Furthermore, studies on machine learning-based radioisotope identifiers for plastic scintillation detectors are limited. Materials and Methods: In this study, machine learning-based radioisotope identifiers were implemented, and their performances according to data normalization methods were compared. Eight classes of radioisotopes consisting of combinations of 22Na, 60Co, and 137Cs, and the background, were defined. The training set was generated by the random sampling technique based on probabilistic density functions acquired by experiments and simulations, and test set was acquired by experiments. Support vector machine (SVM), artificial neural network (ANN), and convolutional neural network (CNN) were implemented as radioisotope identifiers with six data normalization methods, and trained using the generated training set. Results and Discussion: The implemented identifiers were evaluated by test sets acquired by experiments with and without gain shifts to confirm the robustness of the identifiers against the gain shift effect. Among the three machine learning-based radioisotope identifiers, prediction accuracy followed the order SVM > ANN > CNN, while the training time followed the order SVM > ANN > CNN. Conclusion: The prediction accuracy for the combined test sets was highest with the SVM. The CNN exhibited a minimum variation in prediction accuracy for each class, even though it had the lowest prediction accuracy for the combined test sets among three identifiers. The SVM exhibited the highest prediction accuracy for the combined test sets, and its training time was the shortest among three identifiers.