Establishing a Detection Threshold for Acoustic-Based External Leak Detection Systems

A better understanding of the sensitivity threshold of external leak detection systems can assist pipeline operators in predicting detection performance for a range of possible leak scenarios, thereby helping them to make more informed decisions regarding procurement and deployment of such systems. The analysis approach described herein was developed to characterize the leak detection sensitivity of select fiber optic cable-based systems that employ Distributed Acoustic Sensing (DAS). The detection sensitivity analysis consisted of two steps. The first step involved identifying a suitable release parameter capable of providing a defensible basis for defining detection sensitivity; the second step involved the application of logistic regression analysis to characterize detection sensitivity as a function of the chosen release parameter. The detection sensitivity analysis described herein provides a means by which to quantitatively determine the leak detection sensitivity threshold for each technology and sensor deployment position evaluated in a set of full-scale tests. The chosen sensitivity threshold measure was the release parameter value associated with release events having a 90% probability of being detected. Thresholds associated with a higher probability level of 95% were also established for comparison purposes. The calculated sensitivity thresholds can be interpreted to mean that release events associated with release parameter values above the sensitivity threshold have a very high likelihood (either 90 or 95%) of being detected.

LEARNER-DRIVEN ORAL ASSESSMENT CRITERIA FOR ENGLISH PRESENTATION

Learner-centred assessment has been widely propagated in learner-centred approach. However, learners are rarely given the opportunity to engineer their own assessment. Therefore, this study attempted to gauge (1) the functionality of learner-driven oral assessment criteria scaling structure and (2) the reliability of learner-assessors in applying their own assessment criteria during oral presentation. In this study, 11 participants from an electrical engineering group, which consists of one year programme matriculation students, participated in assessment criteria development. First, participants discussed suitable criteria and scaling structure in small groups. Secondly, each group presented their oral assessment criteria for peer feedback. Thirdly, participants discussed and finalised the oral assessment criteria for the class. Fourthly, to test the learner-driven assessment criteria, three speakers from the group volunteered to present their speech. While presenting, these speakers were assessed by their peers. Participants’ ratings and scores were later analysed using the Many-Facet Rasch Measurement (MFRM) software. Findings show that despite the criteria being developed by learners, the scaling structures were functioning usefully with the Rasch Threshold measure indicated more than 1.4 logits between assessment levels and the learner-assessor reliability was > 0.80. The significance of this study lies in raising awareness for improving learners’ oral presentation skills as well as developing learner autonomy. Keywords: Learner autonomy, learner-centred, oral skills, Rasch measurement. Cite as: Idris, M. & Abdul Raof, A. H. (2019). Learner-driven oral assessment criteria for English presentation. Journal of Nusantara Studies, 4(1), 365-383. http://dx.doi.org/10.24200/jonus.vol4iss1pp365-383

PROSES PEMBENIHAN DAN AKLIMATISASI MIKROORGANISME DARI LIMBAH PABRIK PERMEN UNTUK LUMPUR AKTIF

To process wastes biologically beside knowing quality of wastes a seeding process and a microbial acclimatization are needed in order to develop microbes capable of degrading organic compounds in the wastes. Samples were taken from aeration tank of PT. Van Melle Indonesia, a candy factory, which were then poured into separated tank to be batch-aerated for 4 months. Such a microbial seeding plays an important role in aerobically waste treatments. Beside COD,VSS values being a seeding-threshold measure (more than 3000 mg/l) for being used in an aerobe process. During 1 month seeding the VSS concentration was high, i.e. approximately 6000 mg/l. However, the effi ciency of COD removal was not appropriate because of high organic loads. Thus, nutrient-less treatments were run for 2 weeks seeding (day-57 to day-75). During theperiod VSS concentrations decreased from 6000 mg/l to 4000 mg/l. After nutrients additions on day-78 VSS start to increase along with the increasing of COD values. During day-94 to day-118 period, the achieved effi ciency of COD removal was more than 80% although the VSS values were low. At day-124 VSS concentration was 3122 mg/l and COD removal effi ciency was 91%.After the seeding process was stabilized then an acclimatization step, i.e. a process to adapt microorganisms to wastewater being treated, was performed. This process was carried out in a batch type digester. Adapting process was run by substituting glucose with wastewater being treated. The fi nal process was COD removal effi ciency of more than 80%.Key words : Microorganisms, aerobe, aeration, VSS, COD.

Pain threshold - measure of pain sensitivity or social behavior?

The aim was to examine the effect of the experimenter?s social status and its interaction with participant?s gender on pressure pain threshold. Both male and female students participated in the study (N = 96) and were evenly assigned into two groups which differed only in the professional status of the experimenter who was a professor (higher status) in one group and a student (lower status) in the other. The factorial ANOVA revealed statistically significant and large main effects of the experimenter?s status and the participants? gender, indicating higher pain thresholds in male participants and in the higher status experimenter group. Although both males and females had higher pain thresholds when measured by a higher status experimenter, a statistically significant interaction revealed that status affected male participants more so than females. The obtained results are probably due to social behaviour, emphasizing relevance of the experimenter?s and participants? characteristics in pain measurement.

Psychological test performance and sedation thresholds of elderly dements, depressives and depressives with incipient brain change

SynopsisAs expected, dements, depressives and patients with a mixed psychopathology were differentiated from one another on the sedation threshold measure and on a number of psychological tests. In depressives responding to treatment significant changes in physiological and psychological measures, which had been reported in an earlier study, could not be replicated except for an increase of psychomotor speed. In the present sample of patients there were significant correlations between various psychological measures and between them and the levels of the sedation threshold, suggesting that sedation thresholds and psychological tests measured related cerebral functions. Evidence obtained from the earlier investigations to the effect that cerebral age changes short of those occurring in dementia may facilitate the occurrence of depression in late life was only weakly confirmed by the replication study.

The Reliability of Electrodermal Audiometry with Aphasic Adults

Forty hospitalized male aphasic subjects were tested to determine if electrodermal audiometry would yield more reliable auditory thresholds than Standard pure-tone tests. Each subject received a Standard pure-tone test to establish thresholds at 1,000 and 2,000 Hz in both ears, an EDR threshold measure of the same frequencies, and two exact replications of both tests, adminstered one to four weeks later. The data suggest that EDR audiometry can be reliably applied to aphasic males.

The Occlusion Effect in Bone Conduction Hearing

This experiment tested the hypothesis that the occlusion effect is accompanied by an increase in sound pressure level in the external auditory canal. Pure tone bone conduction thresholds and sound pressure levels were measured, first with the ear canal open, then with the ear canal closed, at two positions of the bone vibrator and at five frequencies in 28 normal listeners. Statistical analyses revealed a significant difference between measures at 250, 500, and 1 000 cps but not at 2 000 and 4 000 cps. Average sound pressure level shifts tended to be larger than their threshold measure counterparts. The two measures, nevertheless, yielded positive correlations.