• The Journal of Korean Physical Therapy
• /
• v.27 no.3
• /
• pp.169-173
• /
• 2015

Purpose: This study aimed to improve the asymmetrical weight-bearing ratio, by applying different repetitive sit-to-stand training methods to the paretic-side foot of hemiplegic patients, as well as to provide the necessary information for applying balance training with hemiplegic patients. Methods: The subjects were divided into two groups: a spontaneous foot group and an asymmetrical foot group. They all performed repetitive sit-to-stand training five times a week for a total of six weeks. The sit-to-standing movement was studied using standardized clinical tests. The Biodex Balance System, Time up and go test (TUG), 5 times sit-to-stand test (5XSST), and functional reach test (FRT) were used to measure the static and dynamic standing balance of the patients. Results: In the balance system measurement, the results for the overall index, ant-post index, med-lat index, fall risk index, 5XSST, and FRT after the training differed significantly between the comparison groups (p<0.05). In the evaluation of dynamic balance, the differences in TUG did not differ significantly between the comparison groups after the training (p>0.05). Conclusion: The study found that the asymmetrical group showed significant increases in static and dynamic balance in comparison to the spontaneous group after repetitive sit-to-stand training. Based on this result, it is clear that training in an asymmetrical position with the paretic foot back can increase the left-right stability limit and the anterior-posterior stability limit, thus improving balance control.

• Computers and Concrete
• /
• v.22 no.5
• /
• pp.481-492
• /
• 2018

In this paper, a new hybrid fiber system (NHFS) is investigated for the application of slab. The steel fiber, polyvinyl alcohol (PVA) fiber and calcium carbonate ($CaCO_3$) whisker is added to form NHFS. The four-point bending test is carried out on the flexural properties of slab with plain, steel fiber, traditional hybrid fiber system (THFS) and NHFS reinforced cementitious composites. The flexural behavior is evaluated by ASTM C1018-97, JCI-SF4 and post-crack strength (PCS) technique. The evaluation parameters of flexural toughness such as toughness index (TI), equivalent flexural strength (EFS) and PCS are determined. The size of slab specimens is $15mm(thickness){\times}50mm(width){\times}200mm(length)$. The results show that adding $CaCO_3$ whisker to THFS can significantly improve the flexural strength, TI, EFS, PCS of the slab. The empirical relation between reinforcing index ($RI_v$) and flexural parameters show that flexural parameters of slabs increase first and then decrease; which indicates that optimum $RI_v$ values can be helpful in the considering the mix design of steel-PVA fibers-$CaCO_3$ whisker composites for achieving the desired flexural-related properties. The scanning electron microscopy is performed to observe the micro-morphological characteristics of the fracture surface, which proved the positive hybrid effect among the different fibers in cementitious composites. The NHFS can arrest the generation and propagation of the crack from micro to macro level.

• Journal of the Ergonomics Society of Korea
• /
• v.33 no.5
• /
• pp.407-422
• /
• 2014

Objective: The purpose of the study is to develop quantitative usability evaluation criteria for senior-friendly autonomous transportation robot. Background: The Republic of Korea has become the most rapidly aging society, and is anticipated to enter the post-aged society in 2026. To raise the quality of life of a senior with limited mobility and to reduce the burden of caregivers, many high-tech assistive products with information technologies are developed nowadays. The senior-friendly autonomous transportation robot is one person robot vehicle to move a senior to the destination for hospitals, nursing homes or silver town complex. With built-in navigation system and environmental monitoring censors, it automatically seeks the path to the destination and avoids collision to obstacles and pedestrians on the way. Due to the early stage of the product, few usability studies in this field have been done, mostly on general service robots to assist seniors, power wheelchairs and delivery robots. ISO and KS standards for the service robots are focused on safety. Method: Based on the reference usability index, the early draft of the usability evaluation questionnaires was developed. After small group tests and interviews, the experts modified the initial draft to the Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot (UEC-SFATR). Result: UEC-SFATR consisted of 4 subscales - Safety, Controllability, Efficiency and Satisfaction. All of the 4 subscales of UEC-SFATR were passed the reliability criteria by 4 groups of seniors, divided by gender and familiarity of smart-devices. Conclusion: UEC-SFATR covers wider area of user experiences of the SFATR and is a good measurement tool to help both the users and developers of the robot. Application: This study provides guide to the future product development and product competitiveness evaluation by quantifying user experiences for the SFATR.

• Journal of Korean Medicine Rehabilitation
• /
• v.26 no.4
• /
• pp.67-75
• /
• 2016

Objectives The purpose of this study was to investigate the clinical usefulness of M-test (Meridian test) as an adjunctive evaluation and treatment in patients with chronic neck pain. Methods This study was a single arm pre-post comparison study. Thirty-six eligible subjects with chronic neck pain were recruited from August to September, 2015. M-test was used for evaluating the condition of meridian, which can induce the limitation of ROM and body discomfort. Subjects were offered intradermal acupuncture treatment on one-acupoint for 48 hours. Cervical numeric rating scale (NRS), cervical range of motion (ROM), neck disability index (NDI) and surface electromyography (SEMG) were measured before and after the treatment. Total NRS and the number of movement limitation of M-test were also measured before and after the treatment. Results Among the 36 participating subjects, 4 subjects were lost to follow-up or excluded in accordance with the criteria. Significant differences on Cervical NRS and NDI were found after the treatment (p<0.001). There was a significant difference in the range of left cervical rotation (p<0.05). Root mean square (RMS) of SEMG significantly decreased on the right sternocleidomastoid muscle (p<0.05), but significantly increased on the right trapezius muscle (p<0.05). Median frequency (MdF) of SEMG significantly increased on both sternocleidomastoid muscles. There appears to be significant differences after the treatment in total NRS and the number of movement limitation of M-test (p<0.05). Conclusions These results suggest that the evaluation and treatment of M-test based on the meridian and collateral theory were effective on cervical NRS and NDI, and also improved the movability of human body.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.31 no.3
• /
• pp.59-70
• /
• 2023

In order to predict low-level wind shear at Incheon International Airport (RKSI), a Low-Level Wind Shear prediction system (KMAP-LLWS) along the runway take-off and landing route at RKSI was established using Korea Meteorological Administration Post-Processing (KMAP). For the performance evaluation, the case of low-level wind shear cases calculated from Aircraft Meteorological Data Relay (AMDAR) from July 2021 to June 2022 was used. As a result of verification using the performance evaluation index, POD, FAR, CSI, and TSS were 0.5, 0.85, 0.13, and 0.34, respectively, and the prediction performance was improved by POD, CSI, and TSS compared to the Low-Level Wind Shear prediction system (LDPS-LLWS) calculated using the Korea Meteorological Administration's Local Data Assimilation and Prediction System (LDAPS). This means that the use of high-resolution numerical models improves the predictability of wind changes. In addition, to improve the high FAR of KMAP-LLWS, the threshold for low-level wind shear strength was adjusted. As a result, the most effective low-level wind shear threshold at 8.5 knot/100 ft was derived. This study suggests that it is possible to predict and respond to low-level wind shear at RKSI. In addition, it will be possible to predict low-level wind shear at other airports without wind shear observation equipment by applying the KMAP-LLWS.

• Knowledge Management Research
• /
• v.7 no.1
• /
• pp.49-63
• /
• 2006

The objective of the study is to verify the discriminatory power of technology innovation in predicting Early Stage Ventures' success or failure. To accomplish this objective, we test early stage ventures'(Firm's period is below 3 years)technology innovation and performance. The result of the study is expected to be useful in loan evaluation, investment decision, internal management decision making and business improvement. The results of study is as follows. First, Early Stage Ventures' technology innovation power is composed of 4 major indexes(technology, marketability, manufacturing infra and economic feasibility). Second, we find that thirty-seven minor indexes are significant ex-ante variable which are discriminating between firms' success and failure in Early Stage Ventures. Also thirty-seven minor indexes explain 57.2% of the total variance. This explainable power of these indexes is similar to that of the existing 58 index elements. Finally, we find that the most important technology innovation power of Early Stage Ventures' is economic feasibility.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.40 no.2
• /
• pp.1-17
• /
• 2015

In this paper, we propose a portfolio selection model utilizing a Markov chain for investing in the foreign exchange market based on market forecasts and exchange rate movement predictions. The proposed model is utilized to compute optimum investment portfolio weights for investing in margin-based markets such as the FX margin market. We further present an objective investment algorithm for applying the proposed model in real-life investments. Empirical performance of the proposed model and investment algorithm is evaluated by conducting an experiment in the FX market consisting of the 7 most traded currency pairs, for a period of 9 years, from the beginning of 2005 to the end of 2013. We compare performance with 1) the Dollar Index, 2) a 1/N Portfolio that invests the equal amount in the N target assets, and 3) the Barclay BTOP FX Index. Performance is compared in terms of cumulated returns and Sharpe ratios. The results suggest that the proposed model outperforms all benchmarks during the period of our experiment, for both performance measures. Even when compared in terms of pre- and post-financial crisis, the proposed model outperformed all other benchmarks, showing that the model based on objective data and mathematical optimization achieves superior performance empirically.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.5
• /
• pp.53-60
• /
• 2018

In particular, the investigation of tendons in PSC Box Girder Bridge should be done in a systematic way. It is important to identify preventative maintenance activities that should be carried out in order to analyze the risk factors by type of representative tensions and to reduce risks in the long term. However, in the current maintenance system, various methodologies for investigating and repairing tensions have been studied, but it is difficult to investigate precisely tensions. Therefore, to apply the risk assessment for screening of tensions to the domestic PSC Box Bridge, we presented a risk matrix evaluation index that is consistent with the state assessment and maintenance system.

• PNF and Movement
• /
• v.20 no.2
• /
• pp.263-273
• /
• 2022

Purpose: Translation and adaptation involve cross-cultural and conceptual aspects; they are not simply based on linguistic equivalence. This study aimed to produce a conceptually equivalent Korean version of the motor activity log (K-MAL) for the upper extremities that can be applied across the Korean population and its cultures. Methods: Following the procedures used in the translation of other cross-cultural evaluation tools, and the five steps of the translation process, the motor activity log (MAL) was translated into Korean (K-MAL). We then examined the content validity of the K-MAL. Twenty-two rehabilitation professionals (11 males and 11 females, mean length of clinical career = 101.54 months) assessed the content validity of the K-MAL. The content validity ratio and content validity index were used to verify the content validity. Results: There were inconsistencies found in three sub-items in the MAL during the forward translation process. These inconsistencies were corrected, and the complete K-MAL was produced. The exact critical values of the content validity ratio and the content validity index of the K-MAL were 0.45-0.95 and 0.77-1.00, respectively. Conclusion: The K-MAL was successfully developed using a systematic methodology, which included translation, adaptation, and evaluation of the content validity. We expect that stroke rehabilitation professionals working in both clinical and research settings will apply the K-MAL when evaluating the amount and quality of use of the upper extremities in post-stroke patients in Korea.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.3
• /
• pp.106-115
• /
• 2011

This study proposed a new methodology for seismic capacity evaluation of low-rise reinforced concrete (RC) buildings based on non-linear required spectrum. In order to verify the reliability of the proposed method, relationships between results obtained using the proposed method and the non-linear dynamic analyses were investigated. Compared with the seismic protection index (Es=0.6) defined in the Japanese Standard, the applicability of the method was also estimated. Research results indicate that the method proposed in this study compares reasonably well with the detailed evaluation methods. Using the seismic evaluation method developed in this study, the seismic capacity category and earthquake damage degree of low-rise RC buildings corresponding to a specific earthquake level can be effectively estimated.