• Journal of Korean Neurosurgical Society
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• v.54 no.6
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• pp.484-488
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• 2013

Objective : To examine the synergistic effects of both computer-assisted cognitive rehabilitation (CACR) and transcranial direct current stimulation (tDCS) on cognitive function in patients with stroke. Methods : The current double-blind, sham-controlled study enrolled a total of 11 patients who were newly diagnosed with stroke. The patients of the tDCS group (n=6) completed sessions of the Korean computer-assisted cognitive rehabilitation program five times a week for 30 minutes a session during a mean period of 18.5 days concomitantly with the anodal tDCS over the bilateral prefrontal cortex combined with the CACR. The patients of the control group (n=5) also completed sessions of the sham stimulation during a mean period of 17.8 days. Anodal tDCS over bilateral prefrontal cortex (F3 and F4 in 10-20 EEG system) was delivered for 30 minutes at an intensity of 2 mA. Cathode electrodes were applied to the non-dominant arm. All the patients were evaluated using the Seoul Computerized Neuropsychological Test (SCNT) and the Korean Mini-Mental State Examination. Results : Mann-Whitney U test revealed a significant difference between the two groups. The patients of the tDCS group achieved a significant improvement in the post/pre ratio of auditory continuous performance test and visual continuous performance test on the SCNT items. Conclusion : Our results indicate that the concomitant use of the tDCS with CACR to the prefrontal cortex may provide additional beneficial effects in improving the cognitive dysfunction for patients with stroke.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.261-267
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• 2020

Objective : We investigated the effect of hypnotics on sleep quality, cognitive function, and depressive mood in patients with insomnia following brain tumor resection. Methods : From patients who underwent brain tumor resection, we recruited 10 patients with insomnia who received hypnotics for more than 1 week during a 3-week follow-up period (insomnia group). We also recruited 12 control patients with brain tumors but without insomnia (control group). We evaluated sleep quality at baseline and 3 weeks later using the Insomnia Severity Index (ISI), the Pittsburgh Sleep Quality Index (PSQI), the Stanford Sleepiness Scale (SSS), and the Epworth Sleepiness Scale (ESS) and investigated cognitive function and depression using the Computerized Neuropsychological Test and the Beck Depression Inventory (BDI). Results : At baseline, SSS, ISI, PSQI, and BDI scores were significantly higher and visual continuous performance test (VCPT) and auditory continuous performance test (ACPT) scores were significantly lower in the insomnia than in the control group. Three weeks later, the patients who had received hypnotics had significantly higher ISI, PSQI, ESS, VCPT, ACPT, visual span forward and backward, and visual recognition test scores, and significantly lower BDI scores. Conclusion : Quality of sleep in patients with insomnia following brain tumor resection was initially poor but improved significantly after taking hypnotic medication. Further, the hypnotic medications appeared to contribute to the amelioration of cognitive impairments and depressive moods in patients who previously underwent brain tumor resection. We thus recommend the use of hypnotics for patients with brain tumors with insomnia.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.273-286
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• 1997

Objective：This study was designed to evaluate effects of methylphenidate(MPH) on event-related potentials(ERP) and continuous performance test(CPT) in attention-deficit hyperactivity disorder (ADHD) and to see the correlation between changes in ERP and changes in performance. Method：ERP and CPT were used to examine the acute effects of MPH(0.5mg/kg) in eleven ADHD boys(89-103 months old). Results：1) After MPH administration, P3 latency to nontarget stimuli at Fz was significantly decreased (p<0.01) and P2 amplitudes to target stimuli at Pz and at Oz and P3 amplitude to target stimuli at Cz were significantly increased(p<0.05). 2) Commission error and omission error in the CPT-X and commission error in the CPT-AX were decreased(p<0.01), and hits and perceptual sensitivity(d') in the CPT-X and d′ in the CPT-AX were increased(p<0.01). 3) The change of P3 latency to nontarget stimuli at Fz and the change of d′ in the CPT-X were negatively correlated(p<0.05), and the change of P2 amplitude to target stimuli at Pz and d′ in the CPT-AX were positively correlated(p<0.05). Conclusion：MPH improves change orienting reaction, the delivery of task relevant information, accuracy and perceptual sensitivity in ADHD. And the increase of ability to discriminate targets from non-targets reflects reduced evaluation time in large memory component task and enhanced change orienting reaction in simple task.

• Journal of the Korea Concrete Institute
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• v.26 no.2
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• pp.219-227
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• 2014

The purpose of this study is to investigate water purification properties of porous concrete by using effective microorganisms through the long-term continuous flow test. To solve the problems such as desorption of conventional microorganisms, in this study, tertiary treatment of the effective microorganisms identified by 16S rDNA sequence analysis was adopted per each step in the manufacturing process of porous concrete. And concentration for optimum continuous flow test and operation conditions through basic experiments according to retention time were investigated. Based on the experimental results, the porous concrete applying effective microorganisms showed no toxicity on the biological water quality and exhibited excellent removal efficiency than normal porous concrete. Therefore, contaminated water quality would be improved by treatment performance investigation of contaminants through long-term continuous flow test. If problems are complemented during the experiment process, it is expected to be able to reduce the non-point pollution sources flowing into river.

• KIISE Transactions on Computing Practices
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• v.23 no.2
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• pp.85-96
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• 2017

IoT-Cloud service, integration of Internet of Things (IoT) and Cloud, is becoming a critical model for realizing creative and futuristic application services. Since IoT machines have little computing capacity, it is effective to attaching public Cloud resources for realizing IoT-Cloud service. Furthermore, utilizing containers and adopting a microservice architecture for developing IoT-Cloud service are useful for effective realization. The quality of microservice based IoT-Cloud service is affected by service function chaining which inter-connects each functions. For example, an issue with some of the functions or a bottleneck of inter-connection can degrade the service quality. To ensure functionality of the entire service, various test procedures considering various service environments are required to improve the service continuously. Hence in this paper, we introduce experimental realization of continuous integration based on DevOps and employ application performance monitoring for Node.js based IoT-Cloud service. Then we discuss its effectiveness.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.611-622
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• 2007

In the design and construction of the coastal/offshore structures, it is very important to evaluate the geotechnical characteristics of marine soils, which support the structures. Although the offshore site investigation is much more difficult than onshore, safe and precise jobs have not been accomplished in Korea because of the insufficiency of the test equipments especially for the site with deep water depth. The main objective of this study is to develop a new type of marine cone penetration testing(CPT) system, which can be utilized to even deep sea and high depth of soil layer. The system is one of seabed types and employs the conventional cone, which shows more reliable results than miniature cone. The most important parts of the marine CPT including continuous rod system, cone penetration system with wheel drive, automatic cone rod assembly/dissembly system etc., were designed and manufactured. Some tests to verify the developed marine CPT system were performed at both onshore and offshore sites as well as mechanical test in laboratory. The test results show the consistent and promising performance of the new equipment, and thereafter the system would be applicable to various sites with practical/economical advantages.

• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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• pp.20-26
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• 2012

An APU(Auxiliary Power Unit) for helicopters has been developed in Korea and tested at the AETF(altitude engine test facility) in KARI(Korea Aerospace Research Institute) for the purpose of the military qualification. A cell correlation test was performed before the official test, and the results are within the tolerance. The APU has the capability of supplying electric power as well as compressed air to the helicopters. It was tested at bleed extraction conditions, electric power extraction conditions, and maximum continuous concurrent power conditions within the entire helicopter flight envelop. Some special test equipments were implemented for the measurement of air flowrate, electric power and so on. The tests were successfully performed and their results satisfy the requirements of the helicopters.

• Journal of the Korea Management Engineers Society
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• v.23 no.4
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• pp.73-86
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• 2018

Most electric products produced during the manufacturing process are produced after design and mass production under a given control standard. In particular, the development phase should present the criteria for the production process by setting appropriate limits based on the performance being targeted. Even if the standard of performance is set considering the performance of the process, measuring the performance of the product after actual production results will cause nonconformities with the expected results. Among the performance of electrical products, Energy standards represented by energy consumption efficiency continue to be of importance, and are mandatory standards that correspond to national standards in most countries. Therefore, statistical quality control of these standards shall basically have a large number of test equipment for each product, ensure sufficient test time and continuous sampling of product samples. In the end, companies that produce and sell electric appliances are striving to control mass production at a great cost, but this is not acceptable. This study presents basic characteristics of the energy efficiency of electrical products and proposes and conducts a case study on statistical production control methods for performance variation across products under the standards about domestic and international regulations.

• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.481-490
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• 1998

A computer vision system to measure low flow rate of solid particles was developed and tested to examine its performance with various sized 7 kinds of seeds, perilla, mung bean, paddy, small red bean, black soybean, Cuba bean and small potato tuber. The test was performed for two types of particle flow, continuous and discontinuous. For the continuous flow tested with perilla, mung bean and paddy, the tests resulted correlation coefficients for the flow rates measured by the computer vision and direct method about 0.98. Average errors of the computer vision measurement were in a range of 6∼9%. For the discontinuous flow tested with small red bean, black soybean, Cuba bean and small potato tuber, the tests resulted correlation coefficients for the flow rates measured by the computer vision and direct method 0.98∼0.99. Average errors of the computer vision measurement were in a range of 5∼10%. Performance of the computer vision system was compared with that of the conventional optical sensor to count particles in discontinuous flow. The comparison was done with black soybean, Cuba bean and small potato tuber, and resulted that the computer vision has much better performance than the optical sensor in a sense of precision of the measurement.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.349-360
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• 2009

The cone penetration test(CPT) has gained its popularity in site characterization indebted by its reliability, speed, economy, and automatic measurement system since its development in the 1930s. The CPT results, commonly consisting of cone tip resistance, sleeve friction, and pore water pressure measurements, allow us to classify soils as well as to reveal their engineering characteristics. The site condition at which the CPT is allowable is often dependent on the capacity of a CPT system. In Korea, it has been considered that the CPT could be appled only to soft soils in most cases because CPT systems available for stiff soils are very rare due to their expensive procurement and maintenance cost. Luoisiana Transportation Research Center(LTRC) has developed and implemented a field-rugged continuous intrusion miniature cone penetration test(CIMCPT) system since the late 1990s. The miniature cone penetrometer has a sectional cone area of $2cm^2$ allowing system capacity reduction compared to the standard $10cm^2$ cone penetrometer. The continuous intrusion mechanism allows fast and economic site investigation. Samsung Engineering & Construction has recently developed and implemented a similar CIMCPT system based on its original version developed in LTRC. The performance of the Samsung CIMCPT system has been investigated by calibration with the standard CPT system at a well-characterized test site in Pusan, Korea. In addition, scale effect between the miniature cone penetrometer and the standard cone penetrometer has been investigated by comparing the field test results using the both systems.