• Korean Journal of Applied Biomechanics
• /
• v.27 no.3
• /
• pp.165-169
• /
• 2017

Objective: The Star Excursion Balance Test (SEBT) and Y-Balance Test (YBT) have been commonly applied to measure dynamic postural stability ability. These two tests are utilized interchangeably in various settings. However, they could in fact require different movements to assess dynamic postural stability, as one uses a platform and different measuring techniques than the other. The purpose of this study was to determine if there was a significant difference in the kinematic patterns in physically active population while performing the SEBT and the YBT. Method: Seventy participants performed in the Anterior (AN), Posteromedial (PM), and Posterolateral (PL) directions of the SEBT and the YBT. The kinematics of hip, knee, and ankle in sagittal plane was calculated and analyzed. Paired-sample t-tests were performed to compare joint angular displacement in the ankle, knee, and hip between the SEBT and the YBT. Results: Significant differences in angular displacement at the hip, knee, and ankle joints in the sagittal plane between performance on the SEBT and on the YBT were observed. Conclusion: Clinicians and researchers should not apply these dynamic postural control tasks interchangeably from one task to another. There appear to be kinematic pattern differences between tests in healthy physical active population.

• The Korean Journal of Applied Statistics
• /
• v.19 no.3
• /
• pp.461-479
• /
• 2006

This paper derives joint and conditional Lagrange multiplier tests based on Double-Length Artificial Regression(DLR) for testing functional form and/or the presence of individual(time) effect in a panel regression model. Small sample properties of these tests are assessed by Monte Carlo study, and comparisons are made with LM tests based on Outer Product Gradient(OPG). The results show that the proposed DLR based LM tests have the most appropriate finite sample performance.

• Corrosion Science and Technology
• /
• v.17 no.2
• /
• pp.74-80
• /
• 2018

The electronic industries require environmentally-friendly and highly functional materials to enhance the quality of human life. Home appliances require insect repellent steels that work to protect household microwave ovens from incurring damage by insects such as fire ants and cockroaches in tropical regions. Thus, POSCO has developed new types of functional steels, coated with an array of organic-inorganic hybrid composites on the steel surface, to cover panels in microwave ovens and refrigerators. The composite solution uses a fine dispersion of hybrid solution with polymeric resin, inorganic and a pyrethroid additive in aqueous media. The hybrid composite solution coats the steel surface, by using a roll coater and is cured using an induction curing furnace on both the continuous galvanizing line and the electro-galvanizing line. The new steels were evaluated for quality performances, salt spray test for corrosion resistance and biological performance for both insect repellent and antimicrobial activity. The new steels with organic-inorganic composite coating exhibit extraordinarily biological functionalities, for both insect repellent and antimicrobial activities for short and long term tests. The composite-coating solution and experimental results are discussed and suggest that the molecular level dispersion of insecticide on the coating layer is key to biological functional performances.

• Journal of Drive and Control
• /
• v.16 no.4
• /
• pp.38-47
• /
• 2019

In this paper, a real-time simulation model of an excavator using Amesim was proposed, considered the operation of functional valves with the main control valve (MCV). The hydraulic system models including the pump and MCV have been developed. The kinematic and dynamic models of the manipulator have also been developed, to confirm the behavior of the excavator. The MCV model includes various functional valves such as the regenerative valves, holding valves, swing and boom priority valves, and regen-cut valves so that simulations similar to real excavators can be performed. Additionally, to obtain the real-time calculation performance, the parts with no major influence on the dynamic behavior were simplified, high frequency factors were removed, and parameters were optimized. The models were compared with each other through the numerical analysis with variable time-step and fixed time-step, and the results were verified by comparison with the results of the actual vehicle tests.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.152-155
• /
• 1993

Protective Relay in power system play a prominent part in minimizing power delivery interruptions and help to get a fast and secure restoration when a failure occurs. In order to meet the higher functional requirements in power system, the performance tests on response characteristic of protective relay is essential to ensure reliability. The purpose of this study is as follows: In order to evaluate performance of protective relay, it is intended to develop performance of digital protective relay simulator which is composed of digital protective relay part, behaviour analysis part, waveform generation part and simulation program to simulate pour system in detail.

• Sleep Medicine and Psychophysiology
• /
• v.6 no.2
• /
• pp.143-148
• /
• 1999

Objectives: We studied correlations between neuropsychological tests and perceptual disorder in patients with head trauma and psychiatric patients in order to explore the functional localization of brain in perceptual disorders. Methods: Halstead Reitan Neuropsychological Test Battery, Korean Wechsler Intelligent Scale, and Minnesota Multiphasic Peronality Inventory(MMPI) were administered to one hundred ninteen patients consisting of sixty nine psychiatric patients and fifty patients with brain damage. We tested the correlation between results of neuropsychological tests and peceptual disorder scale PDS) made from nine items related with perceptual disorder in MMPI. T-tests between twenty one higher scorers and seventeen lower scorers of PDS were also performed in the psychiatric group. Results: In brain damage group, significant correlations were found in tests related with function of frontal lobe such as category tests, trail making tests, tactual performance test, and fingertip number writing test, and significant correlations were also noted in the tests related with function of right hemisphere such as tactual performance test, performance, picture completion, picture arrangement and block design. Tests related with subcortical function such as digit symbol test, arithmetic and digit span were signigicantly correlated, too. In psychiatric group, there were significant differences of PDS in the tests related with function of right hemisphere such as picture completion, block design, and right laterality index, and in the tests related with function of left hemisphere such as comprehension, vocabulary, and similarities. Conclusion: Perceptual disorder seems to be related with functions of frontal lobe, right hemisphere, and subcortex in both groups. In a psychiatric group, left hemisphere may be also partially related with perceptual disorder.

• Sleep Medicine and Psychophysiology
• /
• v.1 no.1
• /
• pp.76-86
• /
• 1994

Objectives: This research was performed in order to observe the neuropsychological implication and functional anatomical source of event related potentials(ERP) by studying of correlations between event related potentials and neuropsychological tests. Methods: The latency and voltage of P100 of visual evoked potential (VEP), and N120 and P300 of event related potentials were studied in 56 patients and their correlations with neuropsychological tests were computed. Results: The tests showing significant correlation with latency P100 were visual continous performance test(VCPT) and contingent continous performance test(CCPT) without any significant correlation with voltage of P100. In latency of N120 category test and verbal IQ of KWIS showed significant correlation, and in voltage of N120, finger tapping test, VCPT, CCPT and digit symbol test displayed significant correlations. The latency of P300 had significant correlation with trail making A test and Stroop test. In the voltage of P300 significant correlations were shown with trail making B test, digit symbol test and Wechsler memory scale, finger tapping test, stroop test, VCPT and CCPT. Conclusion : N120 may be considered to reflect the function of medial frontal lobe and P300 may be considered to be developed from the subcortical connection of medial temporal lobe, hippocampus, thalamus, basal ganglia and medial frontal lobe.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.2
• /
• pp.99-114
• /
• 2022

Crowdfunding is one of new financing alternatives and is innovative and creative. In order to proceed with crowdfunding, various functions are required, such as design for screen composition, marketing and promotion for the public, accounting to manage the collected funds, and product production and purchase for reward. In addition, since it is a project that must be completed in a short period of time, cooperation between team members is important. This paper studied how the characteristics of the team conducting crowdfunding affect the team performance in crowdfunding. In this study, we set functional background diversity and shared leadership necessary for crowdfunding as team characteristic variables and crowdfunding amount, completion of work and team innovation as team performance variables. This study tests the hypotheses from 220 university students in 79 teams. The findings suggest that functional diversity and shared leadership are positively related to the completion of work and team innovation but not related to crowdfunding amount. To date, few studies have studied the relationship between characteristics of the crowdfunding team and performance. Therefore, the study on functional diversity and shared leadership in crowdfunding can expand existing crowdfunding study area.

• Journal of the Korean Geotechnical Society
• /
• v.40 no.4
• /
• pp.113-126
• /
• 2024

Shotcrete lining is an important material for the stability of tunnels in NATM tunnels. However, stressmeters for stress measurements of shotcrete lining are installed in the field without performance verification because of a lack of research on methods, procedures, regulations, and reliability of measurement equipment. To solve this problem, all shotcrete stressmeters currently used in Korea were investigated. For each stressmeter, external inspection and structural and functional inspection were performed to identify defects and problems in devices. For this purpose, a shotcrete stressmeter performance test device capable of load loading in stages was developed and obtained KOLAS certification. Using the device, stressmeter performance tests were conducted. Structural problems of integrated- and cell-type shotcrete stressmeters were identified through concrete mold tests, and improvement plans and performance verification procedures were suggested. The results of this study are expected to contribute to the preparation of regulations for the performance verification of shotcrete stressmeters and the selection of measuring instruments in the field in the future.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.660-665
• /
• 2011

In this paper we investigated a variety of candidate trains in KORAIL and Seoul Metro Corp. for an experimental driving which would be in the prosecution of making functional and performance experimentation for the specified manual by this project. We examined many preliminary out-of-service trains and some kinds of spare trains to secure two composition of test-trains for CBTC evaluation and studied a remaking scheme to convert control vehicles of these trains to CBTC-functioned ones to choose a most suitable ones of them, so we will be make traveling tests on the test railroad with them.