• Advances in concrete construction
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• v.5 no.1
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• pp.31-48
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• 2017

Supplementary cementitious materials (SCM) have turned out to be a vital portion of extraordinary strength and performance concrete. Metakaolin (MK) is one of SCM material is acquired by calcinations of kaolinite. Universally utilised as pozzolanic material in concrete to enhance mechanical and durability properties. This study investigates the fresh and hardened properties of conventional concrete (CC) and self compacting concrete (SCC) by partially replacing cement with MK in diverse percentages. In CC and SCC, partial replacement of cement with MK varies from 5-20%. Fresh concrete properties of CC are conducted by slump test and compaction factor tests and for SCC, slump flow, T500, J-Ring, L-Box, V-Funnel and U-Box tests. Hardened concrete characteristics are investigated by compressive, split tensile and flexural strengths at age of 7, 28 and 90 days of curing under water. Carbonation depth, water absorption and density of MK based CC and SCC was also computed. Fresh concrete test results indicated that increase in MK replacement increases workability of concrete in a constant w/b ratio. Also, outcomes reveal that concrete integrating MK had greater compressive, flexural and split tensile strengths. Optimum replacement level of MK for cement was 10%, which increased mechanical properties and robustness properties of concrete.

• Journal of muscle and joint health
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• v.25 no.3
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• pp.167-175
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• 2018

Purpose: The aim of this study was to test the effects of passive exercise on upper extremities muscle spasticity, finger edema, and depression for chronic stroke patients. Methods: A non-equivalent pretest-posttest design was employed for this study. The subjects were 30 elderly patients who were hospitalized to treat chronic stroke. 15 patients were assigned to the experimental and control groups respectively. Passive exercise for 20 minutes per day, five days a week for 8 weeks (total 40 times) was provided for the experimental group. Outcome measurements included manual spasticity test to measure upper extremities' muscle spasticity, the ring measurement method for finger edema and the Korean version of Short-form Geriatric Depression Scale (SGDS-K) for depression. Results: The upper extremities' muscle spasticity (Z=-2.52 p=.012) and the degree of depression (F=5.56, p=.006) in the experimental group were significantly reduced compared to those of the control group. But the degree of finger edema did not significantly differ between the two groups (F=1.46, p=.240). Conclusion: Passive exercise for upper extremities should be encouraged for elderly patients with chronic stroke to enhance the upper extremities' functional capacity as well as depression.

• Advances in concrete construction
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• v.14 no.2
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• pp.139-151
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• 2022

Filling materials poured into precast member joint are subjected to restraint stress by the precast member and joint reinforcement. The induced stress will likely cause cracks at early ages and performance degradation of the entire structure. To prevent these issues and design reasonable joints, it is very important to analyze and evaluate the restrained shrinkage cracks of filling materials at various restraint conditions. In this study, a new time zero-that defines the shrinkage development time of a filling material-is proposed to calculate the accurate amount of shrinkage. The tensile stresses and strengths at different ages were compared through the ring test (AASHTO PP34) to evaluate the crack potential of the restrained filling materials at various restraint conditions. The mixture which contained an expansive additive and a shrinkage reducing agent exhibited high resistance to shrinkage cracking owing to the high-drying shrinkage compensation effect. The high-performance, fiber-reinforced cement composite, and ultra-high-performance, fiber-reinforced cement composite yielded very high resistance to shrinkage and cracking owing to the pull-out property of steel fibers. To this end, multiple nonlinear regression analyses were conducted based on the test results. Accordingly, a modified tensile stress equation that considered both the geometric shape of the specimen and the intrinsic properties of the material is proposed.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.81-88
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• 2016

PURPOSE: This study was aimed at investigating the types of gender roles and the relationship between gender roles and job satisfaction among neurological physical therapists. METHODS: The study subjects were 169 (male 74, female 95) neurological physical therapists working at general hospitals or rehabilitation centers in the Daejeon Metropolitan City area, South Korea. To identify job satisfaction scores, the subjects completed a questionnaire, and a vernier caliper was used by a trained examiner to measure the lengths of the subjects' index and ring fingers (i.e., digitus secundus manus and digitus annularis, respectively) to examine gender roles. The index to ring finger length ratio (i.e., 2D:4D ratio) was calculated using a personal computer. An independent t-test was performed to compare the finger length ratio and job satisfaction of male group with that of the female group and a correlation analysis was performed to examine job satisfaction by gender roles. RESULTS: Finger length ratio is lower in males than in females. However, there was no significant difference statistically (p>.05). Regarding job satisfaction by gender, males were more satisfied with their jobs than females (p<.05). However, there were no significant correlations between job satisfaction and gender roles (p>.05). CONCLUSION: It cannot be concluded that bias against gender roles is a contributing factor for neurological physical therapists being satisfied with their job, and thus bias against gender roles among neurological physical therapists should be removed.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1109-1120
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• 2019

In the field of VLBI, If the quality of the connected network between the VLBI station and the correlation center is ensured, the existing inefficiency of repeatedly storing the observation data in each station and the correlation center can be overcome. In other words, the data center can be unified with the correlation center where data analysis is performed, which can improve data processing speed and productivity. In this paper, we design a massive VLBI data system that directly transmits and stores the observation data stream obtained from the VLBI station to the correlation center via the high - speed network KREONET. Based on this system, VLBI test observations confirmed that the observation data was stored perfectly in the recording system of the correlation center without a single packet loss.

• Journal of Biomedical Engineering Research
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• v.33 no.4
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• pp.169-176
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• 2012

Tumor cell morphology is closely related to its migratory behaviors. An active tumor cell has a highly irregular shape, whereas a spherical cell is inactive. Thus, quantitative analysis of cell features is crucial to determine tumor malignancy or to test the efficacy of anticancer treatment. We use 3D time-lapse phase-contrast microscopy to analyze single cell morphology because it enables to observe long-term activity of living cells without photobleaching and phototoxicity, which is common in other fluorescence-labeled microscopy. Despite this advantage, there are image-level drawbacks to phase-contrast microscopy, such as local light effect and contrast interference ring. Therefore, we first corrected for non-uniform illumination artifacts and then we use intensity distribution information to detect cell boundary. In phase contrast microscopy image, cell is normally appeared as dark region surrounded by bright halo ring. Due to halo artifact is minimal around the cell body and has non-symmetric diffusion pattern, we calculate cross sectional plane which intersects center of each cell and orthogonal to first principal axis. Then, we extract dark cell region by analyzing intensity profile curve considering local bright peak as halo area. Finally, we calculated the Fourier descriptor that morphological characteristics of cell to classify tumor cells into active and inactive groups. We validated classification accuracy by comparing our findings with manually obtained results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1044-1051
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• 2006

System level diagnosis algorithms use the properties of t-diagnosable system where the maximum number of the faults does not exceed 1. The existing diagnosis algorithms have limit when dealing with large fault sets in large multiprocessor systems. Somani and Peleg proposed t/k-diagnosable system to diagnose more faults than t by allowing upper bounded few number of units to be diagnosed incorrectly. In this paper, we propose adaptive hypercube diagnosis algorithm using t/k-diagnosable system. When the number of faults exceeds t, we allow k faults to be diagnosed incorrectly. Simulation shows that the performance of the proposed algorithm is better than Feng's HADA algorithm. We propose new algorithm to reduce test rounds by analyzing the syndrome of RGC-ring obtained in the first step of HADA/IHADA method. The proposed algorithm also gives similar performance compared to HYP-DIAG algorithm.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.1
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• pp.51-56
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• 1981

A new I2L process for a high performance I2L structure is proposed. The modifiedstructure consists of a heavily doped extrinsic base and lowly doped intrinsic base where the collector regions are self-alignment with the intrinsic base regions. The proposed process untilizes spin-on sources as the diffusion sources and the self-alignment of collectors is achieved by using the hardened spin-on source as a diffusion mask. Test devices including a 13-stage ring oscillator have been fabricated by the proposed process on n/n+ silicon wafers with 6.5$\mu$m epitaxial layer. The maximum upward current gain of npn transistors is 8 for a three collector I2L cell. The speed-power product and minimum propagation delay for a one collector structure are 3.5 pJ and 50 ns, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.2
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• pp.134-141
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• 2013

This paper explores a real-time system implementation to couple tightly StrapDown Inertial Navigation System(SDINS) and Global Positioning System(GPS) mounted on the aircraft. When implementing the SDINS/GPS coupled system in real-time processor, we have to deliberate SDINS's unique characteristics based on the ring laser gyro, and besides, lever-arm, measurements, and error compensation method. The novel modeling method is applied to system the misalignment error term of gyro to estimate the cumulative heading attitude errors while the aircraft banking to turn repeatedly. Captive Flight Test results show that the proposed modeling strategy has good performance.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.2
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• pp.33-37
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• 2016

One-way degassing valves usually designed for coffee packaging are recently applied to the various food packaging such as fermented health functional food or home meal replacement (HMR) packaging. The optimized degassing pressure by food product is important factor for keeping effective freshness and improving preservation of the food, therefore the development of degassing valves specified with various open pressure is needed. In this study, the mechanical characteristics of the degassing valve with ring type rubber disk were analyzed and a mathematical model was developed to predict the open pressure of the valve. The model was verified with test results derived from several available valves, and it may be useful in designing and developing a new valve.