• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.6
• /
• pp.2359-2368
• /
• 2013

Cone penetration tests (CPTs) have been increasingly used for site characterizations. However, the site investigations using CPTs are often limited due to soil conditions depending on the cone size and capacity of the CPT system. The small sectional area of a miniature cone improves the applicability of the CPT system due to the increased capacity of the CPT system. A continuous intrusion system using a coiled rod allows fast and cost effective site investigation. In this study, the performance of the continuous intrusion miniature cone penetration test (CIMCPT) system has been evaluated by comparison tests with the standard CPT system at several construction sites in Korea. The results show that the CIMCPT system has a same performance with the CPT system and has advantages on the mobility and applicability. According to field verification tests for scale effect evaluation, the cone tip resistance evaluated by CIMCPT overestimates by 10% comparing to standard CPTs. A crawler mounted with the CIMCPT system has been implemented to improve accessibility to soft ground, and has shown improvement over the truck type CIMCPT system. Therefore, the improved CIMCPT system can be utilized as a cost effective and highly reliable soil investigation methodology to detect the depth of soft ground and to evaluate soil classification.

• Journal of Advanced Navigation Technology
• /
• v.26 no.1
• /
• pp.1-8
• /
• 2022

Telemetry system is a system that measures and transmits status information in the aircraft to the ground. The data received from the ground is information for monitoring the state of the aircraft, and can be checked and analyzed in real time through the test program. Data processing test system for telemetry currently in operation is built to transmit data using wired communication and perform test. As smart devices become popular due to the continuous development of information and communication technology, wireless communication networks are becoming important, and technologies for improving performance are steadily being developed. In this paper, we suggests and builds data processing ground test system for telemetry using wireless communication(Wi-Fi) that can be checked through smart devices such as tablets, in order to break away from the existing method and apply future-oriented technology. Finally, the suggested test system performance was proved by testing in various environments by linking test equipment and test program.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.19 no.2
• /
• pp.112-119
• /
• 2008

Objectives : This study was conducted to examine whether there are qualitative differences in attention problem among children with various psychiatric disorders, including attention-deficit hyperactivity disorder (ADHD), depressive disorder, anxiety disorder, and tic disorder using clinical ADHD diagnostic system (ADS) T-scores. Methods : The subjects were 794 outpatient children aged from 5 to 15 years, including 540 children with ADHD, 95 children with depressive disorder, 86 children with anxiety disorder, and 73 children with tic disorder. Clinical T-scores on the ADS were calculated using the mean and standard deviations of four ADS variables for the ADHD group. Results : All four groups had T-scores on the ADS in the abnormal range. However, when comparing the clinical T-scores, the children with depressive and anxiety disorders performed better than the children with ADHD. We also found that although the four groups seemed to be similar in terms of clinical T-scores for omission and commission errors, there were significant differences in clinical T-scores for reaction time and the standard deviation of response time (RT) between the ADHD and other groups. Conclusions : We concluded that inattention and impulsivity might not be specific only to ADHD and that the clinical T-scores of RT and standard deviation of RT on the ADS could be used to discriminate between ADHD and other clinical groups.

• Journal of Ginseng Research
• /
• v.43 no.3
• /
• pp.402-407
• /
• 2019

Background: To investigate the neurobiological evidence supporting the adaptogenic effects of Korean Red Ginseng in reducing the harmful consequences of stress using a double-blind, placebo-controlled trial. Method: Sixty-three subjects with high stress levels were randomized to receive an orally administered, double-blind, 6-week treatment with Korean Red Ginseng (n = 32) or placebo (n = 31). All participants underwent a comprehensive psychological evaluation using Beck Depression Inventory and Stress Response Inventory, cognitive evaluation using the continuous performance test, biological evaluation by measuring blood levels of lipids, catecholamines, inflammation markers, and heart rate variability at baseline and after 6 weeks. Results: At baseline, both groups showed no significant differences in age, sex, years of education, Beck Depression Inventory, and Stress Response Inventory. After 6 weeks, triglyceride levels were significantly increased within the normal limit in the Korean Red Ginseng group (F = 4.11, p = 0.048), and the epinephrine level was decreased in this group (F = 4,35, p = 0.043). The triglyceride increase was significantly associated with epinephrine decrease (B = 0.087, p = 0.041), suggesting that Korean Red Ginseng may stabilize the sympathetic nervous system. In addition, we detected a significant group by time effect in the visually controlled continuous performance test, suggesting positive effects of Korean Red Ginseng on cognition. Conclusion: Korean Red Ginseng might help to stabilize the sympathetic nervous system and improve cognition in individuals with high stress.

• International Journal of Internet, Broadcasting and Communication
• /
• v.13 no.1
• /
• pp.1-10
• /
• 2021

The type approval system for railway vehicle has been in effect since 2016 in order to establish a regular safety management system to secure railway safety and enhance the technological competitiveness of the railway industry, abolished the conventional performance test system through the reform of the Railroad Safety Act in 2012. Until now, there has been appreciated it has been making significant contributions to railway safety and industry of operation and manufacturing companies, taking their place in accordance with the implementation of the system. But there has been no case of quantitative analysis on the effectiveness of the actual system. In this study, in order to examine the full-scale performance of the approval system and quantitatively analyze effectiveness, we identified and defined the relationships with the major elements of the type approval system based on system thinking principle and determined the calculated outcomes to relevant stakeholders. A method of establishing a type approval performance management system that can be grasped, utilized, and adjusted from a point of various stakeholders' views was proposed. This is expected to be more helpful in the implementation of the system, such as improving and applying quantitative effects to analysis by closely reviewing the effects and influencing factors of the type approval system based on the data accumulated through continuous performance management and reflecting to system improvement.

• Journal of Korean Neurosurgical Society
• /
• v.63 no.1
• /
• pp.45-55
• /
• 2020

Objective : Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro. Methods : Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1-C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily. Results : In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10-20 ㎍/mL) for 5 days and 4 days in assays of half and total exchange of PBS. Conclusion : This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.10
• /
• pp.523-530
• /
• 2020

The efficient market hypothesis explains the random walk hypothesis suggesting that stock prices are independent of each other, hence, it is impossible to earn abnormal profits. The positive effect of a well-functioning and highly efficient stock market on the performance of an economy motivated the Philippine Stock Exchange to pursue massive modernization initiatives. This research provides evidence of the existence of random walk in the Philippine stock market employing the Augmented Dickey-Fuller (1981) and Phillips-Perron (1988) unit root tests, the Lo-MacKinlay's (1988) conventional variance ratio test, and Chow-Denning's (1993) simple multiple variance ratio test. Results of the ADF and PP unit root tests confirm the necessary condition for a random walk. The Chow-Denning (1993) maximum /z/ statistic and the Wald test statistic as in Richardson and Smith (1991) for the joint hypotheses and the Lo and MacKinlay (1988) individual statistics variance ratio test generally accepted the null hypothesis of a random walk. That is, the unit root and variance ratio tests consistently indicate that the null hypothesis of random walk cannot be rejected. The existence of a random walk in weak-form efficiency can be attributed to market liquidity as a result of continuous development and modernization of the Philippine equity market.

• Korean Journal of Biological Psychiatry
• /
• v.21 no.2
• /
• pp.65-73
• /
• 2014

Objectives This study aimed to identify the differences and the profiles of cognitive deficits in remitted patients with schizophrenia and first-degree relatives of schizophrenic probands. Methods A total of 26 remitted states of schizophrenia patients were included in the study and the same number of unaffected first-degree relatives of schizophrenic probands and healthy controls were matched for age, sex, years of education. Cognitive function of all participants was measured by using the Digit span test, the Continuous performance test, the Rey auditory & visual learning test, the Complex figure test, the Verbal fluency test, the Wisconsin card sorting test and the Finger tapping test. The effects of subsyndromal symptomatology and general intelligence score were controlled. Results Schizophrenia patients' group showed more significant impairment than other groups in verbal memory (learning, immediate recall, delayed recall), visual memory (copy, immediate recall, delayed recall) and cognitive flexibility domains. The family group and the patient group commonly performed significantly worse than healthy controls in working memory and verbal fluency (category) tests. There were no differences in sustained attention, psychomotor performance. Conclusions Our research shows that the deficit in working memory and verbal fluency could be strong candidates of endophenotypic marker in schizophrenia.

• Journal of Information Technology Applications and Management
• /
• v.14 no.1
• /
• pp.1-20
• /
• 2007

IT outsourcing becomes one of the important shills for managing diverse and complex information systems, SIA is considered as an one of the success factors for the successful outsourcing management. Since it helps to establish common goal and provides better visibility of trends and performance, the SLA process must go beyond mere measurement to include a methodology for the ongoing management of service levels, and for the continuous improvement of service activities, functions and processes. Despite SLA is one of the most important skills for the successful outsourcing, few studies have been conducted for academic as well as practical purpose. For this reason, The objective of this study is to develop an SLA's maturity model and empirically demonstrate how SLA's maturity level affects its Performance through SLA's maturity model. The major contributions of this study are in two areas. This study contributes to academicians as well as practitioners. First, from the academic perspectives this study tries investigating the maturity level of the SLA based on empirical data. Second, practitioners can self-test their firms' maturity level using the proposed model. The results of this study show that the SLA's maturity level affected positively SLA's performance. It is founded that the SLA's maturity level had a significant impact on SLA's performance.

• Progress in Superconductivity and Cryogenics
• /
• v.20 no.3
• /
• pp.28-33
• /
• 2018

With the continuous performance improvement and commercialization of HTS wires, there have been many efforts to commercialize HTS power cables recently. Unlike conventional power cables, a cryogenic cooling system is required for a HTS power cable and a cryogenic pump is one of the essential components to circulate subcooled liquid nitrogen and cool the HTS power cable. Especially, the development of a reliable and high-efficiency cryogenic pump is an important issue for the commercialization of HTS power cables of several kilometers or more. In this study, we designed and fabricated a cryogenic pump for subcooled liquid nitrogen with a mass flow rate of 1.2 kg/s, a differential pressure of 5 bar, and evaluated the hydraulic performance of the pump. Impeller design was conducted to meet the target design performance with 1 D analysis model and CFD analysis. The pump performance parameters such as pressure heads, mass flow rates, and efficiencies in accordance with rotating speeds were assessed using a laboratory's performance evaluation system.