• Food Engineering Progress
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• v.13 no.4
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• pp.308-313
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• 2009

This study was conducted to design and fabricate a heat pump that can produce some weather conditions similar to those of the dry season of the rough rice in Korea, and to investigate basic performances of the apparatus. During the drying test, the amount of energy consumption and drying characteristics were measured at four different temperature levels ranging between 20$^{\circ}C$ and 50${^{\circ}C}$. In the psychrometric chart, the freezing capacity and refrigerant circulation ratio of the heat pump were 173 kJ/kg and 49.6 kg/hr, respectively. Therefore, coefficient of performance was 5.5, which was superior to that of refrigerant R-22 (4.0) in standard refrigeration cycle. In addition, the time to reach target drying temperature (30${^{\circ}C}$) and relative humidity (40%) were 6 minutes and 7 minutes, respectively. Temperature differences between the drying temperature and the rice were 1.5${^{\circ}C}$ and 8.5${^{\circ}C}$ at the drying temperatures of 21.9${^{\circ}C}$ and 48.7${^{\circ}C}$, respectively. This result demonstrated that the increased temperature of the rice in the drying section decreased sufficiently in the tempering section. At the drying temperatures of 21.9, 30.7 38.8, and 48.7${^{\circ}C}$, drying rates were 0.29, 0.61, 0.85, and 1.26%/hr, respectively, which were similar to those of commercial dryer. In addition, the amounts of energy consumption were 325, 667, 692, and 776 kJ/kg, respectively. These results showed that this dryer saved up to 86% of energy consumption compared with the commercial dryer, which uses 4,000-5,000 kJ/kg of fossil fuel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.472-482
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• 2019

This paper describes the stabilization of underwater TAS winch system Deploy/Recover operation performance. TAS winch installed on the stern of submarine performs to deploy/recover sensor, towing cable and rope tail which is deployed from the stern and separated from submarine itself. Also TAS winch provides transmission path of power to the sensor and data transmitting/receiving path which data are acquired from underwater environment like sound, depth and temperature. At the step of TAS winch evaluation test, sporadic standstill and rotating speed oscillation phenomenon were occurred. Winch motor provides the available torque to deploy/recover TAS and root cause analysis to the winch motor was done to find exact reason to sporadic malfunction. When winch motor was disassembled, eccentricity of rotor, slip-ring and the other composition part for winch motor were found. These might cause magnetic field distortion. To make TAS winch system more stable and block magnetic field distortion, this paper suggests methods to enhance fixing status installed in winch motor. For reliable data acquisition for TAS winch operation, the deploy/recover function of the improved type of TAS winch was verified in LBTS making similar condition with sea status. At the end of stage, improved type of TAS winch was tested on some functions not only deploy/recover function, but sustainability of TAS operation on specific velocity, steering angle of submarine in the sea trial. Improved type of TAS winch was verified in accordance with design requirement. Also, validity of suggested methods were verified by the sea trial.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.252-258
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• 2018

A larger energy consumption and concentration of population induced green house gas glowing and heat island effect in the urban space. Roof green system was a effect method to reduce green house gas and heat concentration in the city. Therefore, construction of this system was increasing. Most of lightweight soil used in roof green system was perlite, but this caused dust and skin disease. So it needed to develop another new lightweight soli for roof green system. Meanwhile, a thermoelectric power plant generated bottom ash as a by-product. According to previous research, bottom ash could be used for artificial lightweight soil with 60 wt% of mixing rate. But this study was proceed to develop a artificial lightweight soil using bottom ash with higher mixing rate by 65 wt% and different organic ingredients. First, physical and chemical properties of bottom ash was investigated. Then test according to landscaping design standard was proceeded for various artificial lightweight soil mix types using bottom ash, bark, compost and coco peat. As a result, the artificial lightweight soil with 65% of bottom ash, 30% of bark and 5% of compost was suitable for low and middle range of soil standard.

• The Journal of Korean Academy of Sensory Integration
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• v.16 no.2
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• pp.64-74
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• 2018

Objective : The purpose of this study is to examine the effects of therapeutic interventions on upper extremity function of children with cerebral palsy using systematic review methods and to suggest intervention trends in Korea. Methods : The subjects of the study were the researches published in the Korean Journal since 2008. Total 12 studies were selected through Korean research database engine such as DBpia, Scholar, KSDC, KISS and RISS for the systematic review. Key words were 'cerebral palsy', 'upper extremity function' and 'hand function'. The results of this study were analyzed by qualitative level and methodological quality level of evidence, and the results of each study were analyzed according to the PICO approach, that is Patient, Intervention, Comparison and Outcome. Results : For the level of evidence, Grade IV and V were most frequent. In terms of methodological quality, majority of the studies showed 'Fair' level. The subjects were the children with hemiplegia, and Single-subjects designs and case studies were frequent experimental design. Constraint-induced movement therapy (CIMT) was most frequently conducted among the intervention studies, and Jebsen-Taylor Hand Function Test was most frequently used evaluation tool. Eleven studies showed that the upper limb functions were significantly improved or were positively effective. Conclusion : Various intervention methods have been implemented to improve the upper limb functions of children with cerebral palsy. In the future, studies on intervention methods based on the type of paralysis and studies with high quality of evidence should be conducted in Korea.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.757-763
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• 2018

It is very difficult to achieve sufficient data rate and required quality of service due to the time-varying nature of the radio channel and various jammers such as path loss, delay, Doppler, shadowing and interference. Especially, the propagation path between the transmitting antenna and the tracking antenna mounted on the fuselage during the test and evaluation of the projectile system considered in this paper is based on the rapid movement of the projectile, the interference due to multipath fading due to the terrain, The propagation path may be blocked. In order to effectively improve the multipath fading occurring in the wireless communication system, a diversity combiner technique is required. In this paper, to derive the design and improvement schemes for the space diversity combiner technique among the diversity combiner schemes, the BER performance of maximum ratio combining (MRC) and selection combining (SC) In an adaptive SC / MRC diversity combiner that operates with MRC when it is lower than the specified threshold criterion when comparing the SNR between two signals received from the channel and operates with SC at high and combines the two received signals The BER performance of the system was compared and analyzed.

• Asian Spine Journal
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• v.12 no.6
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• pp.1060-1068
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• 2018

Study Design: Retrospective study. Purpose: Lumbar intervertebral disc degeneration is an important cause of low back pain. Overview of Literature: Spinal fusion is often reported to have a good course for adolescent idiopathic scoliosis (AIS). However, many studies have reported that adjacent segment degeneration is accelerated after lumbar spinal fusion. Radiography is a simple method used to evaluate the orientation of the vertebral column. magnetic resonance imaging (MRI) is the method most often used to specifically evaluate intervertebral disc degeneration. The Pfirrmann classification is a well-known method used to evaluate degenerative lumbar disease. After spinal fusion, an increase in stress, excess mobility, increased intra-disc pressure, and posterior displacement of the axis of motion have been observed in the adjacent segments. Methods: we retrospectively secured and analyzed the data of 15 patients (four boys and 11 girls) with AIS who underwent a spinal fusion surgery. We studied the full-length view of the spine (anterior-posterior and lateral) from the X-ray and MRI obtained from all patients before surgery. Postoperatively, another full-length spine X-ray and lumbosacral MRI were obtained from all participants. Then, pelvic tilt, sacral slope, curve correction, and fused and free segments before and after surgery were calculated based on X-ray studies. MRI images were used to estimate the degree to which intervertebral discs were degenerated using Pfirrmann grading system. Pfirrmann grade before and after surgery were compared with Wilcoxon signed rank test. While analyzing the contribution of potential risk factors for the post-spinal fusion Pfirrmann grade of disc degeneration, we used generalized linear models with robust standard error estimates to account for intraclass correlation that may have been present between discs of the same patient. Results: The mean age of the participant was 14 years, and the mean curvature before and after surgery were 67.8 and 23.8, respectively (p<0.05). During the median follow-up of 5 years, the mean degree of the disc degeneration significantly increased in all patients after surgery (p<0.05) with a Pfirrmann grade of 1 and 2.8 in the L2-L3 before and after surgery, respectively. The corresponding figures at L3-L4, L4-L5, and L5-S1 levels were 1.28 and 2.43, 1.07 and 2.35, and 1 and 2.33, respectively. The lower was the number of free discs below the fusion level, the higher was the Pfirrmann grade of degeneration (p<0.001). Conversely, the higher was the number of the discs fused together, the higher was the Pfirrmann grade. Conclusions: we observed that the disc degeneration aggravated after spinal fusion for scoliosis. While the degree of degeneration as measured by Pfirrmann grade was directly correlated by the number of fused segments, it was negatively correlated with the number of discs that remained free below the lowermost level of the fusion.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.4
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• pp.226-232
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• 2019

This study was aimed to reveal that the usual cold or heat state was associated with hypertension and could be a risk. We emailed educational personnel in D university to join this study and 182 subjects participated in from March to December in 2016. The usual cold or heat diagnosis was conducted by two experts who had over 10 years expertise. The blood pressure was measured from the subjected after 10 minute rest with Jawon medical device. The hypertension was diagnosed by the guide of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. The frequency analysis was used in general characteristics, Pearson's Correlation Coefficient analysis was conducted in among continuous variables, and chi-square test was also used between hypertension and cold or heat group. Logistic regression was analyzed to generate the odds ratios (ORs) and 95% confidence interval (CI) for hypertension. The cold score was suggested to have negative association with Body mass Index (BMI, -.374, p<.001), systolic blood pressure (-.333, p<.001), and diastolic pressure (-.261, p<.001). The heat score was analyzed to have positive association with Body mass Index (.413, p<.001), systolic blood pressure (.249, p<.001), and diastolic pressure (.156, p<.001). The distribution of the cold group (35.1%) and non-cold group (64.9%) in hypertension was significantly different (p=0.18). The distribution of the heat group (62.2%) and non-heat group (37.8%) was significantly different (p=0.27). The usual cold was associated with decreased ORs (ORs 0.405, 95% CI=0.191-0.857), and usual heat was associated with increased ORs (ORs 2.327, 95% CI=1.108-4.888). However, after adjusting body mass index, sex, and smoking, the association was not significantly different. It is possible that usual cold or heat associate with hypertension. Further study is needed to show that usual heat may be a independent risk factor for hypertension through follow up design.

• Journal of the Korean Geotechnical Society
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• v.35 no.7
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• pp.29-39
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• 2019

Load distributive compression anchors distribute the compressive stress in the grout and increase the pull-out capacity of the anchor by using multiple anchor bodies. In this anchor type, the spacing between the anchor bodies has a large influence on the stress in the grout. However, there are few researches about the spacing and there are no design standards. Therefore, the effect of the anchor body spacing on the grout stress was analyzed by performing finite element analyses. First, the applicability of the numerical modeling was verified by comparing with field test results of a compression anchor. Then, the parametric study was performed varying soil type, anchor body spacing, and load magnitude. The analysis results showed that the maximum compressive stress in the grout increased at the narrower spacing and the tensile stress developed at the wider spacing. Therefore, the optimum spacing was defined as the spacing, which prevents the superposition of compressive stresses and minimize the tensile stress. Finally, the optimum spacing was proposed according to the soil type and the load magnitude.

• Animal Bioscience
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• v.34 no.1
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• pp.154-160
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• 2021

Objective: The effect of environmental enrichment on the behaviour of piglets in the nursery phase was evaluated. Methods: A total of 450 hybrid pigs (21 day old), including both females and uncastrated males, weighing approximately 6 kg, were distributed in a completely randomised design with 3 treatments and 3 replicates of 50 animals each. The treatments were: i) pen without environmental enrichment (control), ii) treatment consisting of continuous environmental enrichment (CEE) with rubber balls throughout the experimental period, and iii) treatment consisting of environmental enrichment with washed balls (EEWB) during the whole experimental period which were removed daily for washing. For the behavioural evaluation, 10 animals were randomly selected per replicate. The behavioural assessments were performed once a week, from 8 am to 6 pm, using images captured with a video camera. The data were submitted to non-parametric analyses, the means were compared using the Bonferroni test, and Person's correlations were also calculated. Results: A statistical difference (p = 0.001) was observed in the B5 (playful) behaviour; the animals in the EEWB treatment group had a higher frequency of this behaviour than animals in the control treatment group. The animals in the control group showed a higher frequency of B7 behaviour (lying down) (p = 0.026) than those in the EEWB and CEE treatment groups. The animals in the control group had a higher frequency of the B9 (belly nosing) behaviour than those in the EEWB group (p = 0.015). There was a tendency towards a higher frequency of behaviour B3 (walking in the pen) (p = 0.067) when the animals received the control treatment than treatments EEWB or CEE. Conclusion: The use of an enriching object improved the animal welfare and altered the correlation between the evaluated behaviours compared to the animals that did not have environmental enrichment.

• Journal of the Korean Geotechnical Society
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• v.38 no.4
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• pp.21-32
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• 2022

Steel pile foundations are widely used for offshore constructions due to their high bearing capacity and efficiency. Typically, offshore structures that have reached the end of their design life are required to be demolished. However, pile foundations are often left on site due to technical and economic limitations. The pile left on the site not only pollutes the environment, but can also cause obstacles for the construction of new structures. Therefore, research is required to completely eliminate these foundations at the site. In this study, a new type of double-wall pile foundation that can drastically reduce the pull-out load was conceptually proposed, and a series of model tests were performed to validate the performance of the double-wall pile foundation. The installation and extraction of the double-wall pile were simulated in dry sand in the model test, and the measured up-lift load was compared to that of the conventional pile. According to the result, the maximum up-lift load induced by the decommissioning of the double-wall pile was reduced by 45% when compared to the traditional pile in dense sand. This study verified the mechanism for reducing the up-lift load of the double-wall foundation and confirmed the possibility of completely decommissioning a pile that has reached the end of its nominal service life.