• 대기
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• 제26권3호
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• pp.461-471
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• 2016

A quality check algorithm for the Weather Information Service Engine pulsed Doppler wind lidar is developed from a view point of spatial and temporal consistencies of observed wind speed. Threshold values for quality check are determined by statistical analysis on the standard deviation of 3-component of wind speed obtained by a wind lidar, and the vertical gradient of horizontal wind speed obtained by a radiosonde system. The algorithm includes carrier-to-noise ratio (CNR) check, data availability check, and vertical gradient of horizontal wind speed check. That is, data sets whose CNR is less than -29 dB, data availability is less than 90%, or vertical gradient of horizontal wind speed is less than $-0.028s^{-1}$ or larger than $0.032s^{-1}$ are classified as 'doubtful', and flagged. The developed quality check algorithm is applied to data obtained at Bucheon station for the period from 1 to 30 September 2015. It is found that the number of 'doubtful' data shows maxima around 2000 m high, but the ratio of 'doubtful' to height-total data increases with increasing height due to atmospheric boundary height, cloud, or rainfall, etc. It is also found that the quality check by data availability is more effective than those by carrier to noise ratio or vertical gradient of horizontal wind speed to remove an erroneous noise data.

• 대기
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• 제22권3호
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• pp.299-307
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• 2012

This study is aimed to validate errors for detected suspicious temperature data using various quality control procedures for 61 weather stations in the Republic of Korea. The quality control algorithms for temperature data consist of four main procedures (high-low extreme check, internal consistency check, temporal outlier check, and spatial outlier check). Errors of detected suspicious temperature data are judged by examining temperature data of nearby stations, surface weather charts, hourly temperature data, daily precipitation, and daily maximum wind direction. The number of detected errors in internal consistency check and spatial outlier check showed 4 days (3 stations) and 7 days (5 stations), respectively. Effective and objective methods for validation errors through this study will help to reduce manpower and time for conduct of quality management for temperature data.

• 한국CDE학회논문집
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• 제18권3호
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• pp.177-188
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• 2013

The construction industry consists of various and massive architectural information as an architectural process includes a variety of design stages with cooperation of many disciplines. Particularly, architectural information is generated and managed through the life cycle of a building, from conceptual design stage to the construction and maintenance. A Building Information Model (BIM) serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle from inception onward. BIM technology accomplished quantitative development being utilized in various disciplines. However, it is necessary to develop environment and requirement for qualitative improvement of BIM based project. Particularly, requirement is very important for architectural design evaluations. The purpose of this study is to develop and apply of quality control check-list for improving the quality of architectural design in BIM environments. To achieve this purpose, the authors have investigated case study for open BIM data quality control (software, guideline and application case) and classified quality control targets according to physical/logical quality control and data quality. In addition, the authors have defined open BIM based quality control process and developed quality control check-list. Finally, the authors have developed automatic quality check system using requirements for efficient quality control based on open BIM.

• 대기
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• 제26권4호
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• pp.541-551
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• 2016

A real-time quality control algorithm for $PM_{10}$ concentration measured by Continuous Ambient Particulate Monitor (FH62C14, Thermo Fisher Scientific Inc.) has been developed. The quality control algorithm for $PM_{10}$ data consists of five main procedures. The first step is valid value check. The values should be within the acceptable range limit. Upper ($5,000{\mu}g\;m^{-3}$) and lower ($0{\mu}g\;m^{-3}$) values of instrument detectable limit have to be eliminated as being unrealistic. The second step is valid error check. Whenever unusual condition occurs, the instrument will save error code. Value having an error code is eliminated. The third step is persistence check. This step checks on a minimum required variability of data during a certain period. If the $PM_{10}$ data do not vary over the past 60 minutes by more than the specific limit ($0{\mu}g\;m^{-3}$) then the current 5-minute value fails the check. The fourth step is time continuity check, which is checked to eliminate gross outlier. The last step is spike check. The spikes in the time series are checked. The outlier detection is based on the double-difference time series, using the median. Flags indicating normal and abnormal are added to the raw data after quality control procedure. The quality control algorithm is applied to $PM_{10}$ data for Asian dust and non-Asian dust case at Seoul site and dataset for the period 2013~2014 at 26 sites in Korea.

• 대기
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• 제29권4호
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• pp.501-509
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• 2019

Asian Dust is a meteorological phenomenon that sand particles are raised from the arid and semi-arid regions-Taklamakan Desert, Gobi Desert and Inner Mongolia in China-and transported by westerlies and deposited on the surface. Asian dust results in a negative effect on human health as well as environmental, social and economic aspects. For monitoring of Asian Dust, Korea Meteorological Administration operates 29 stations using a continuous ambient particulate monitor. Kim et al. (2016) developed an automatic quality check (AQC) algorithm for objective and systematic quality check of observed PM₁₀ concentration and evaluated AQC with results of a manual quality check (MQC). The results showed the AQC algorithm could detect abnormal observations efficiently but it also presented a large number of false alarms which result from valid error check. To complement the deficiency of AQC and to develop an AQC system which can be applied in real-time, AQC has been modulated. Based on the analysis of instrument status codes, valid error check process was revised and 6 status codes were further considered as normal. Also, time continuity check and spike check were modified so that posterior data was not referred at inspection time. Two-year observed PM₁₀ concentration data and corresponding MQC results were used to evaluate the modulated AQC compared to the original AQC algorithm. The results showed a false alarm ratio decreased from 0.44 to 0.09 and the accuracy and the probability of detection were conserved well in spite of the exclusion of posterior data at inspection time.

• 지적과 국토정보
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• 제50권2호
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• pp.81-100
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• 2020

본 연구는 풍수해로부터 발생 가능한 피해를 추정하기 위한 공간정보 DB 활용 방안과 공간정보의 품질 점검 기준을 제안하고자 하였다. 국가재난관리정보시스템, 국가공간정보통합체계 공개자료 목록을 대상으로 공간정보 DB 중 풍수해 피해 추정을 위해 활용될 수 있는 데이터를 피해유형별로 매핑하였으며, 해당 데이터를 활용하여 피해 분석을 위한 품질 점검 기준 항목을 제안하였다. 본 연구를 통해 풍수해 피해 추정을 위한 공간정보 DB 활용이 가능할 것이며, 품질 점검 기준을 통해 분석 결과의 신뢰성을 담보할 수 있을 것이다.

• 한국측량학회지
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• 제17권1호
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• pp.79-86
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• 1999

본 논문에서는 국내의 수치지도 검수방법을 고찰하고, 보다 효율적인 검수방법을 제안하였다. 수치지도 검수를 수행하기 위하여 통계적 품질관리기법을 도입하였다. 현재의 통계적인 검수방법(1단 완전 추출법)을 개선하기 위한 표본 추출법으로 2단 완전 추출법과 2단 집락 추출법을 제안하였다. 경험적으로 작성된 자료를 이용하여 납품된 전체 수치지도에 대한 오류율과 누락 객체 수를 추정하였으며, 이에 대한 분산도 추정하였다. 또한, 오류율과 누락 객체 수에 대한 신뢰구간을 결정할 수 있었다.

• 한국항공우주학회지
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• 제41권9호
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• pp.689-699
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• 2013

전리층 폭풍 시 발생할 수 있는 극심한 전리층 이상현상은 GNSS 보강시스템 사용자의 안전을 위협하는 대표적인 요인이므로 전리층 위협모델을 기반으로 한 지상 모니터링을 통해 적시에 감지 및 경보가 이루어 져야한다. GNSS 관측 데이터를 기반으로 전리층 분석을 수행하고 그 결과로 위협모델을 개발하기 때문에 각 관측소의 데이터 품질은 시스템 성능에 큰 영향을 미칠 수 있다. 전 세계적으로 GNSS 상시관측소 수가 많이 증가함에 따라 품질이 떨어지는 데이터를 산출하는 관측소 또한 증가하였다. 본 연구에서는 GNSS 데이터 품질평가 기법 이용하여 국내 GPS 상시관측소 데이터의 품질을 비교하고 품질이 떨어지는 데이터가 전리층 지연오차 및 기울기 추정치에 미치는 영향을 분석하였다. 품질평가 결과 국내 상시관측소간 데이터 품질에 큰 차이를 보였고 이 품질은 일정기간 유지된다는 것을 확인하였다. 본 연구에서 분석한 결과를 바탕으로 전리층 위협모델 개발을 위한 GNSS 데이터 품질 기준을 제시할 수 있다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.284-288
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• 2015

Recently, the mandate on utilizing BIM implemented by public institutions of many countries has great impact on the significantly increasing practices of BIM. The improvement of work efficiency and productivity, which is occurred by BIM adoption, depends on the consistency and accuracy of data. To maximize the benefit of BIM, the interests in BIM data quality have been enlarging all over the world. The BIM data quality pre-check, which is conducted by designer in the design phase, offers opportunities for quality improvement by continuously assessing BIM data. However, BIM quality pre-check is being conducted under arbitrary interpretation of users because of the absence of specific review factors and assessment methods for checking BIM quality. The purpose of this study is to establish an automated BIM quality pre-checking system to improve BIM design quality effectively and efficiently. It could be expected to meet the owner's requirements and to minimize the cost and time occurred additionally from revising and reproducing data by constructing consistency and accuracy of it.

• 품질경영학회지
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• 제50권3호
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• pp.545-570
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• 2022

Purpose: The purpose of this study was to explore dimensions to improve airline non-face-to-face(untact) service quality and identify shadow work dimensions in the digital environment among them. Methods: This study conducted mixed method. First of all, For finding out the dimensions of airline untact service quality, in-depth interviews were conducted from passengers. The collected data through the survey were analyzed using improved importance-performance analysis(IPA). Second, An online survey was conducted to quantitatively analyze user perception about airline untact service quality, and the importance performance of service quality at each dimension was identified through the revised IPA method. Results: The results of this study are as follows; Through in-depth interviews, 11 dimensions found out and 32 measurement items were developed. and then, through the revised IPA analysis, passengers were highly satisfied with "Cleanliness of in-flight service" and "Reliability of self check-in". Also, We found 3 shadow work dimensions such as "Ease of use of self check-in", "Usefulness of self check-in", and "Responsiveness of self check-in". Conclusion: Airline service providers have to keep high-satisfaction services and urgently improve less satisfied services. In particular, the dimensions related to shadow work have to be improved.