• Title/Summary/Keyword: absolute relative bias

Search Result 24, Processing Time 0.019 seconds

Determination of chlorophenols from the industrial wastewater by GC/MS (GC/MS를 이용한 산업폐수중의 염화페놀류 분석)

  • Myung, Seung-Woon
    • Analytical Science and Technology
    • /
    • v.18 no.4
    • /
    • pp.320-328
    • /
    • 2005
  • The most common five chlorophenols (4-chloro-3-methylphenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol) were determined from the industrial wastewater by GC/MS. The samples were collected from the petrochemical company, textile company and leather making company. The developed analytical method was modified by USEPA Method 3510. The samples were extracted with dichloromethane under pH 2 and pH 5-6, and determined by the GC/MS with SIM mode. There were good linearities (above $R^2=0.9943$) on e ranges of the 0.1 ng/mL~10 ng/mL and 0.5 ng/mL~10 ng/mL, and the limit of detection were between 0.1 ng/mL and 0.5 ng/mL. The absolute recoveries were measured at the concentration of 1, 5, and 10 ng/mL, and the recovery was 71.6~98.9% except for PCP. The relative standard deviation (RSD) was 1.2~14.3% and it gave a good reproducibility for the assay. The bias, which shows the accuracy, was a good although it was a little high values (11.3~22.1%) at the low concentration (1 ng/mL).

Evaluation of Measurement Accuracy for Unmanned Aerial Vehicle-based Land Surface Temperature Depending on Climate and Crop Conditions (기상 조건과 작물 생육상태에 따른 무인기 기반 지표면온도의 관측 정확도 평가)

  • Ryu, Jae-Hyun
    • Korean Journal of Remote Sensing
    • /
    • v.37 no.2
    • /
    • pp.211-220
    • /
    • 2021
  • Land Surface Temperature (LST) is one of the useful parameters to diagnose the growth and development of crop and to detect crop stress. Unmanned Aerial Vehicle (UAV)-based LST (LSTUAV) can be estimated in the regional spatial scale due to miniaturization of thermal infrared camera and development of UAV. Given that meteorological variable, type of instrument, and surface condition can affect the LSTUAV, the evaluation for accuracy of LSTUAV is required. The purpose of this study is to evaluate the accuracy of LSTUAV using LST measured at ground (LSTGround) under various meteorological conditions and growth phases of garlic crop. To evaluate the accuracy of LSTUAV, Relative humidity (RH), absolute humidity (AH), gust, and vegetation index were considered. Root mean square error (RMSE) after minimizing the bias between LSTUAV and LSTGround was 2.565℃ under above 60% of RH, and it was higher than that of 1.82℃ under the below 60% of RH. Therefore, LSTUAV measurement should be conducted under the below 60% of RH. The error depending on the gust and surface conditions was not statistically significant (p-value < 0.05). LSTUAV had reliable accuracy under the wind speed conditions that allow flight and reflected the crop condition. These results help to comprehend the accuracy of LSTUAV and to utilize it in the agriculture field.

Qualitative and quantitative PCR detection of insect-resistant genetically modified rice Agb0101 developed in korea (해충저항성 유전자변형 벼 Agb0101에 대한 PCR 검정)

  • Shin, Kong-Sik;Lee, Jin-Hyoung;Lim, Myung-Ho;Woo, Hee-Jong;Qin, Yang;Suh, Seok-Cheol;Kweon, Soon-Jong;Cho, Hyun-Suk
    • Journal of Plant Biotechnology
    • /
    • v.40 no.1
    • /
    • pp.18-26
    • /
    • 2013
  • Genetically modified (GM) rice Agb0101, which expresses the insecticidal toxin modified cry1Ac (mcry1Ac1) gene, was developed by the Rural Development Administration in Korea. To monitor the probable release of Agb0101 in the future, it is necessary to develop a reliable detection method. Here, we developed the PCR detection method for monitoring and tracing of GM rice. The primer pair (RBEgh-1/-2) from a starch branching enzyme (RBE4) gene was designed as an endogenous reference, giving rise to an expected PCR amplicon of 101 bp. For the qualitative PCR detection, construct- and event-specific primers were designed on the basis of integration sequence of T-DNA. Event-specific PCRs amplified specifically 5'- or 3'-junction region spanning the native genome DNA and the integrated gene construct, while none of amplified product was shown on crops, rice varieties, and other insect-resistant transgenic rice lines. The event-specific real-time PCR method was performed using TaqMan probe and plasmid pRBECrR containing both rice endogenous gene RBE4 sequence and 5'-junction sequence as the reference molecule. The absolute limit of quantification (LOQ) of real-time PCR was established with around 10 copies for one plasmid molecule pRBECrR. Thereafter, the different amounts of transgenic rice (1, 3, 5, and 10%, respectively) were quantified by using the established real-time PCR method, with a range below 19.55% of the accuracy expressed as bias, 0.06-0.40 of standard deviation (SD) and 3.80-7.01% of relative standard deviations (RSD), respectively. These results indicate that the qualitative and quantitative PCR methods could be used effectively to detect the event Agb0101 in monitoring and traceability.

Service Quality, Customer Satisfaction and Customer Loyalty of Mobile Communication Industry in China (중국이동통신산업중적복무질량(中国移动通信产业中的服务质量), 고객만의도화고객충성도(顾客满意度和顾客忠诚度))

  • Zhang, Ruijin;Li, Xiangyang;Zhang, Yunchang
    • Journal of Global Scholars of Marketing Science
    • /
    • v.20 no.3
    • /
    • pp.269-277
    • /
    • 2010
  • Previous studies have shown that the most important factor affecting customer loyalty in the service industry is service quality. However, on the subject of whether service quality has a direct or indirect effect on customer loyalty, scholars' views apparently vary. Some studies suggest that service quality has a direct and fundamental influence on customer loyalty (Bai and Liu, 2002). However, others have shown that service quality not only directly affects customer loyalty, it also has an indirect impact on customer loyalty by influencing customer satisfaction and perceived value (Cronin, Brady, and Hult, 2000). Currently, there are few domestic articles that specifically address the relationship between service quality and customer loyalty in the mobile communication industry. Moreover, research has studied customer loyalty as a whole variable, rather than breaking it down further into multiple dimensions. Based on this analysis, this paper summarizes previous study results, establishes an effect mechanism model among service quality, customer satisfaction, and customer loyalty in the mobile communication industry, and presents a statistical test on model assumptions by using customer investigation data from Heilongjiang Mobile Company. It provides theoretical guidance for mobile service management based on the discussion of the hypothesis test results. For data collection, the sample comprised mobile users in Harbin city, and the survey was taken by random sampling. Out of a total of 300 questionnaires, 276 (92.9%) were recovered. After excluding invalid questionnaires, 249 remained, for an effective rate of 82.6 percent for the study. Cronbach's ${\alpha}$ coefficient was adapted to assess the scale reliability, and validity testing was conducted on the questionnaire from three aspects: content validity, construct validity. and convergent validity. The study tested for goodness of fit mainly from the absolute and relative fit indexes. From the hypothesis testing results, overall, four assumptions have not been supported. The ultimate affective relationship of service quality, customer satisfaction, and customer loyalty is demonstrated in Figure 2. On the whole, the service quality of the communication industry not only has a direct positive significant effect on customer loyalty, it also has an indirect positive significant effect on customer loyalty through service quality; the affective mechanism and extent of customer loyalty are different, and are influenced by each dimension of service quality. This study used the questionnaires of existing literature from home and abroad and tested them in empirical research, with all questions adapted to seven-point Likert scales. With the SERVQUAL scale of Parasuraman, Zeithaml, and Berry (1988), or PZB, as a reference point, service quality was divided into five dimensions-tangibility, reliability, responsiveness, assurance, and empathy-and the questions were simplified down to nineteen. The measurement of customer satisfaction was based mainly on Fornell (1992) and Wang and Han (2003), ending up with four questions. Based on the study’s three indicators of price tolerance, first choice, and complaint reaction were used to measure attitudinal loyalty, while repurchase intention, recommendation, and reputation measured behavioral loyalty. The collection and collation of literature data produced a model of the relationship among service quality, customer satisfaction, and customer loyalty in mobile communications, and China Mobile in the city of Harbin in Heilongjiang province was used for conducting an empirical test of the model and obtaining some useful conclusions. First, service quality in mobile communication is formed by the five factors mentioned earlier: tangibility, reliability, responsiveness, assurance, and empathy. On the basis of PZB SERVQUAL, the study designed a measurement scale of service quality for the mobile communications industry, and obtained these five factors through exploratory factor analysis. The factors fit basically with the five elements, indicating the concept of five elements of service quality for the mobile communications industry. Second, service quality in mobile communications has both direct and indirect positive effects on attitudinal loyalty, with the indirect effect being produced through the intermediary variable, customer satisfaction. There are also both direct and indirect positive effects on behavioral loyalty, with the indirect effect produced through two intermediary variables: customer satisfaction and attitudinal loyalty. This shows that better service quality and higher customer satisfaction will activate the attitudinal to service providers more active and show loyalty to service providers much easier. In addition, the effect mechanism of all dimensions of service quality on all dimensions of customer loyalty is different. Third, customer satisfaction plays a significant intermediary role among service quality and attitudinal and behavioral loyalty, indicating that improving service quality can boost customer satisfaction and make it easier for satisfied customers to become loyal customers. Moreover, attitudinal loyalty plays a significant intermediary role between service quality and behavioral loyalty, indicating that only attitudinally and behaviorally loyal customers are truly loyal customers. The research conclusions have some indications for Chinese telecom operators and others to upgrade their service quality. Two limitations to the study are also mentioned. First, all data were collected in the Heilongjiang area, so there might be a common method bias that skews the results. Second, the discussion addresses the relationship between service quality and customer loyalty, setting customer satisfaction as mediator, but does not consider other factors, like customer value and consumer features, This research will be continued in the future.