• Journal of the Korea Concrete Institute
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• v.29 no.1
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• pp.3-10
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• 2017

In case of Korea highways, about 60% of highways are paved by concrete and more than 50% of them were repaired due to reduction in required performance such as damage in pave or joint and delamination of cover pavement. However, repairing old material in such structure generally costs a lot of money and induces difficulty in maintenance. Thus, enhanced material for ensuring economic efficiency should be developed. The present study designed concrete mixtures with 3 levels of replacement using OPC (0, 10, 20%) in calcium aluminate cement and to evaluate material performance for load pavement, experimental works for setting time, compressive strength and flexural strength were carried out on those materials. As a result, 20% replacement for OPC was determined as an optimized material in terms of required physical performance and its unit price. Moreover, to determine cost in load pavement economy analysis using a program (CA4PRS) was conducted with widely used paving materials. Result showed that application for 20% replacement for OPC was the most efficient in economical aspect, arising from 4.052 and 1.577 billion won for total construction and user cost, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.3
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• pp.286-293
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• 1986

The purpose of this study was to investigate the effect of withering on mechanical properties for optimizing the condition of transportation and storage of fresh leafy vegetables which they would be easily able to be suffered the physical damage. Experimental material used were spinaches and leeks which were easily apt to be withered. The breaking stress, elastic modulus and viscosity were measured in the range of temperature $3{\sim}37^{\circ}C$ and water content $70{\sim}95%$ by the four element model, being used the creep tester made by author. As a result of this study, while water content was decreased, breaking stress was increased. The elastic modulus and viscosity of the specimens were not influenced on temperature, but on water content. In reversibility test of the withering, the appearance, water content and elastic modulus of the specimens were completely recovered to the initial freshness, but the viscosity was not.

• Journal of the Korean Geosynthetics Society
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• v.12 no.2
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• pp.13-23
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• 2013

The Korean Peninsula is considered as a seasonal frozen area that is thawed in the spring and frozen in the winter. The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing tests simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the geotechnical structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In this study, ten soil samples are prepared. The basic physical property tests were performed by following the Korean Industrial Standard and the soil specimens were classified by the Unified Soil Classification System (USCS). These classified soils are used to perform the laboratory opened systems freezing test in order to determine the frost heaving characteristics of soils such as unfrozen water content, heaving amount, and freezing depth.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.509-516
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• 2020

The purpose of this study was to examine the effects of a 12-week Resistance exercise Type on Muscle Damaged and Blood Lipid in elderly Women. Study shows researchers randomly divided thirty elderly women into the following 3 Groups such as Control group(CG: n=10), Aquatic Exercise Group(AEG: n=10), circuit exercise group(CEG: n=10). They made each group excercise 3 days a week for 12 weeks. The results were as follows. There was no interaction effect in the TC, LDL-C, HDL-C but there were interaction effects in the Body weight and Body Fat(%). The AEG and CEG decreased than the CG in the Body Weight, Body Fat(%), TC, LDL-C, and increased than the CG in the HDL-C with significant difference. These results were made certain that decreasing the Body Weight and Blood lipid, Increasing the Muscle and HDL-C for elderly women on AEG and CEG. The analysis results of study show the index of TG, CPK, LDH has no significant difference. Besides, It is considerable that the aquatic Exercise and Circuit exercise can prevent and improve the Sarcopenia for elderly women.

• Journal of Korean Clinical Nursing Research
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• v.19 no.3
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• pp.432-442
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• 2013

Purpose: The purpose of this study was to describe restraint use in care of patients with psychiatric disorders in an attempt to avoid unnecessary restraint use and provide information for developing standards regarding restraint use as a therapeutic maneuver. Methods: For this descriptive study, discharge records from N National Mental Hospital in the year 2009 were reviewed by trained nurses during Dec. 24, 2010 and Mar. 31, 2011. There were 596 restrains applied on 232 of 1,322 discharges. Data collected include general characteristic of patients, the frequency of restraint use, time since admission when restraint was applied, time of the day when restraint was applied, duration of restraint application, place of occurrence, reasons for restraint use, and degree of damage to the patent. Work experience of nurses who applied restraints, number of workforce at the time of restraint, and season of the year was also identified. Descriptive statistics, Chi-square test, t-test, ANOVA, $Scheff{\grave{e}}$ and Jonckheere-Terpstra were applied using SPSS 14.0 to analyze the data. Results: There were 596 restraint uses among 232 patients. Restraints were applied most frequently on males in their 40s, patients diagnosed with schizophrenia, and patients repeating admissions more than 6 times. Restraints were frequently applied within first week following admission, between 16:00 and 20:00, and the average duration of restraint was 5 hours. There were significant differences according to diagnoses of patients in the season restraint occured, time, place of occurrence, reason for restraint, and duration of restraint. Patients with alcoholism received longer restraint application. Conclusion: In order to avoid unnecessary restraint use in patients with psychiatric disorders, nurses and other health care team members need to acknowledge a group of patients such as patients with schizophrenia and alcoholism who relatively frequently restrained or receiving longer restraint. Reasonable and careful decision need to be made when applying restraint in the care of patients with alcohol problem.

• Korean Journal of Agricultural Science
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• v.32 no.1
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• pp.29-42
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• 2005

During a long journey of agricultural products from the production area to markets, the quality of agricultural products was always affected by some degree of vibration. The vibration input during the transportation may cause serious agricultural product injury, and this damage is particularly severe whenever the vegetable inside package is free to bounce, and is vibrated at its resonant frequency. The objectives of this study were to determine the resonant frequency of the oriental melon and to investigate the relationships between resonant frequency and physical properties of the oriental melon such as mass, volume and major and minor axes. In this study vibration testing device was constructed to determine the vibration response of the oriental melon in frequency ranges of 5 to 150 Hz. The computer program for controlling the vibration shaker and the function generator and measuring the vibration characteristics of the oriental melon was developed. The ranges of resonant frequency and peak acceleration at resonance of the oriental melon were 51 to 73 Hz and 1.24 to 1.92 G-rms, respectively. The resonant frequency and the peak acceleration decreased with the increase of the sample mass, volume, major and minor axes of the oriental melon. Multiple regression models for resonant frequency and peak acceleration of the oriental melon as a function of mass, major axis and minor axis of the sample were developed and analyzed.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.1-7
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• 2017

As the network environment develops and speeds up, a lot of smart devices is developed, and a high-speed smart society can be realized while allowing people to interact with objects. As the number of things Internet has surged, a wide range of new security risks and problems have emerged for devices, platforms and operating systems, communications, and connected systems. Due to the physical characteristics of IoT devices, they are smaller in size than conventional systems, and operate with low power, low cost, and relatively low specifications. Therefore, it is difficult to apply the existing security solution used in the existing system. In addition, IoT devices are connected to the network at all times, it is important to ensure that personal privacy exposure, such as eavesdropping, data tampering, privacy breach, information leakage, unauthorized access, Significant security issues can arise, including confidentiality and threats to facilities. In this paper, we investigate cases of security threats and cases of network of IoT, analyze vulnerabilities, and suggest ways to minimize property damage by Internet of things.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.791-796
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• 2007

As large-scale buildings, skyscrapers, and multi-purpose buildings recently increase in numbers dramatically, the internal space of such buildings becomes more and more large and complicated accordingly. Since such structures usually accommodate a number of random people, the potential possibilities of disastrous tragedies are high, and the rates of injury and physical damage caused by the complicated system of the building also increase as well. However, most of the shelter designs of the existing buildings are based on the specifications according to the assigned laws and involved regulations. In this case, only general criteria are referred to regardless of the characteristics of each structure while other disaster-related features are not taken into consideration sufficiently. Since any actual fire may cause a terrible calamity, in such plans, shelter inducement can be neither safe nor effective. Thus, this study examines and analyzes currently run disaster prevention systems and shelter inducement facilities with COEX Mall as its subject, and analyzes the responding system to each situation based on the fire scenarios by means of As-Is Model. Through this analysis, presented are the measures to solve the problems of current disaster prevention systems and to improve shelter inducement methods effectively.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.388-393
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• 2013

The study was focused to evaluate the possibility for combination membrane of bacterial cellulose (BC) and graphene with high electrical properties. BC with natural polymer matrix was known to have strong physical strength. For the combination of graphene with BC, the surface of graphene was modified with oxygen plasma by changing strength and time of radio waves in room temperature. Water contact angle of modified graphene grew smaller from $130^{\circ}$ to $12^{\circ}$. XPS analysis showed that oxygen content after treatment increased from 2.99 to 10.98%. Damage degree of graphene was examined from $I_D/I_G$ ratio of Raman analysis. $I_D/I_G$ ratio of non-treated graphene (NTG) was 0.11, and 0.36 to 0.43 in plasma treated graphene (PTG), increasing structural defects of PTG. XRD analysis of PTG membrane with BC was $2{\theta}$ same to BC only, indicating chemically combined membrane. In FT-IR analysis, 1,000 to 1,300 $cm^{-1}$ (C=O) peak indicating oxygen radicals in PTG membrane had formed was larger than NTG membrane. The results suggest that BC as an alternation of plastic material for graphene combination has a possibility in some degree on the part like transparent conductive films.

• Journal of Conservation Science
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• v.31 no.1
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• pp.1-11
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• 2015

Seated Amitabha Triad at Muwisa Temple (Treasure No. 1312) had been known as wooden Buddha statue, but a precise safety inspection revealed that the statue is terracotta Buddha statue made with clay. The clay layer of Amitabha Triad was conserved due to its severe damage. In this study, experiments were conducted to produce the most appropriate filler for the conservation treatment of the seated Amitabha Triad. Mixed clay samples with various ratios were produced and surface hardening state, crack, color change, and shrinkage of the samples during dry process were measured. Loess, fine sand powder, and cotton were used to produce the mixed clay for the filler with six different ratios and then 12 different concentration glues made with glutinous rice glue, Pachymeniopsis Elliptica glue, and animal glue were added as adhesives. Total 72 types of samples were prepared and comparative study was conducted. As a result, when the mixed clay contains 2.5% cotton compared to the weight per cent of loess and fine sand powder and also loess and fine sand in the mixed clay have a 15:1 ratio, the mixed clay had the lowest shrinkage. Animal glue is considered as an appropriate glue since it had small color change, low physical property change and shringkage. Therefore, mixed clay (loess:fine sand=15:1) mixed with 15ml animal glue is likely to be a suitable filler for conservation treatment of the seated amitabha triad at the Muwisa Temple.