• Composites Research
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• v.31 no.5
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• pp.209-214
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• 2018

This paper explain about the development of environmental friendly, low cost and stable supply material i.e., rice husk and shell were used as micro incorporating bio waste filler. Those were processed by ball mill and analyzed through micro observation by FE-SEM, EDS and particle size distribution. The obtained filler was mixed with epoxy resin for the manufacturing of CFRP composite and study tensile properties. In EDS analysis main contents of rice husk and rice husk ash are C, O and Si. When rice husk was burned C and Si ration were increased. Shell powder has C, O and Ca. It caused $CaCO_3$ from shell. Surface weighted mean of rice husk powder is $6.19{\mu}m$ and volume weighted mean is $14.77{\mu}m$. And it has rod type particles which caused hair and husk structure parts. Surface weighted mean of rice husk ash powder is $1.55{\mu}m$ and volume weighted means is $8.20{\mu}m$. Surface weighted mean of shell powder is $2.53{\mu}m$ and volume weighted mean is $5.79{\mu}m$. The tensile decreased with increasing the content of micro filler in CFRP composites. In case of rice husk, the significant decrement of tensile strength was observed. and in case of shell powder, there is no effect of changes take place in tensile strength.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.61-77
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• 2005

Statement of problem. The implant prosthesis has been utilized in various clinical cases thanks to its increase in scientific effective application. The relevant implant therapy should have the high success rate in osseointegration, and the implant prosthesis should last for a long period of time without failure. Resorption of the peri-implant alveolar bone is the most frequent and serious problem in implant prosthesis. Excessive concentration of stress from the occlusal force and biopressure around the implant has been known to be the main cause of the bone destruction. Therefore, to decide the location and angulation of the implant is one of the major considering factors for the stress around the implant fixture to be dispersed in the limit of bio-capacity of load support for the successful and long-lasting clinical result. Yet, the detailed mechanism of this phenomenon is not well understood. To some extent, this is related to the paucity of basic science research. Purpose. The purpose of this study is to perform the stress analysis of the implant prosthesis in the partially edentulous mandible according to the different nature locations and angulations using three dimensional finite element method. Material and methods, Three 3.75mm standard implants were placed in the area of first and second bicuspids, and first molar in the mandible Thereafter, implant prostheses were fabricated using UCLA abutments. Five experimental groups were designed as follows : 1) straight placement of three implants, 2) 5$^{\circ}$ buccal and lingual angulation of straightly aligned three implants, 3) 10$^{\circ}$ buccal and lingual angulation of straightly aligned three implants. 4) lingual offset placement of three implants, and 5) buccal offset placement of three implants. Average occlusal force with a variation of perpendicular and 30$^{\circ}$ angulation was applied on the buccal cusp of each implant prosthesis, followed by the measurement of alteration and amount of stress on each configurational implant part and peri-implant bio-structures. The results of this study are extracted from the comparison between the distribution of Von mises stress and the maximum Von mises stress using three dimensional finite element stress analysis for each experimental group. Conclusion. The conclusions were as follows : 1. Providing angulations of the fixture did not help in stress dispersion in the restoration of partially edentulous mandible. 2. It is beneficial to place the fixture in a straight vertical direction, since bio-pressure in the peri-implant bone increases when the fixture is implanted in an angle. 3. It is important to select an appropriate prosthodontic material that prevents fractures, since the bio-pressure is concentrated on the prosthodontic structures when the fixture is implanted in an angle. 4. Offset placement of the fixtures is effective in stress dispersion in the restoration of partially edentulous mandible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.379-385
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• 2002

Tele-medicine and emergency medical system are necessary for moving from an accidental point or far distance to a hospital and emergency treatment or home treatment before a hospital. Emergency treatment is extremely important in the case of death before arriving a hospital and deformed of disabled by medical treatment delay. A necessary element for this medical system is the emergency communication system. This system is on preparing for an ability of furnishing patient status to a corresponding health service by monitoring the patient at an ambulance of the accident place. This is the transportation of basic biological information of a patient to a medical center by wireless communication system and the corresponding hospital of medical center examine the patient by monitoring, then they can send emergency medical order to the patient for emergency treatment. The TRS is most efficient way of emergency medical communication system, which is currently used with popularity. In this paper studied simultaneously a way of detecting and transporting bio-logical signals, and monitoring of transporting data with communication of voice in the accident place of ambulance.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.235-243
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• 2012

Objectives: The purpose of this study is the work environment management method through risk assessment and investigation of the work place that deals with Ammonium nitrate, based on information in and outside the country. Methods: This study suggests method of work environment management through risk assessment and investigation of the work place that deals with Ammonium nitrate, and finds out cases of Ammonium nitrate causing hazard, danger and health risk, based on literature investigation. Results: Rats exposed repeatedly to $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin) which cause high level of skin irritation, reported 1 $mg/m^3$ of NOAEL, while LOAEL was less than 100 mg/kg for the rats orally administered with the $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin), for 13 weeks. Domestically 31,640 ton/y of ammonium nitrate has been used in 22 workplace and the result of workplace assessment was 0.0171-0.9983 $mg/m^3$. ADD was 8.77-59.63 ${\mu}g/kg-day$ according to the exposure scenario. In other words the result of the risk assessment goes beyond the 'standard 1'. Conclusions: Ammonium nitrate creates a high level of irritation and toxicity when coming in breathe it or contact with skin, and is classified as category3 of GHS and specific target organ toxicant (irritating respiratory system). Exposure level at work places needs to be maintained under $1mg/m^3$, to prevent workers from being damaged.

• Journal of Biosystems Engineering
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• v.26 no.3
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• pp.245-252
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• 2001

This study was carried out to investigate the effect of three factors(dynamic load, inflation pressure and multiple passes of the tire) on the contact pressure and the soil stresses under the tire. A series of soil bin experiment was conducted with a 6.00R14 radial-ply tire for sandy loam soil. Tire contact pressure at soil surface and soil stresses at 10cm and 20cm soil depth were measured for the three levels of dynamic load(1.17kN, 2.35kN and 3.53kN), for the three levels of tire inflation pressure(103.42kPa, 206.84kPa and 413.69kPa), and for five different number of passes(1, 2, 3, 4 and 5 pass). The following results were drawn from this study 1) As dynamic load, inflation pressure and number of passes of the tire increased, tire contact pressure at soil surface and soil stresses at 10cm and 20cm soil depth increased accordingly. Thus increased in dynamic load, inflation pressure and number of passes of the tire would increase soil compaction. 2) The effect of three different factors, or dynamic load, inflation pressure and number of passes of the tire, decreased as the soil depth increase. Consequently, it was found that the soil compaction at a shallow depth in soil is larger than that at deep place in soil. 3) The increase of dynamic load and number of passes increased soil stress exponentially, but the increase of inflation pressure increased soil stress linearly. The effect of tire inflation pressure on soil stress was relatively less than that of the dynamic load. Therefore, it was concluded that dynamic load is more important factor affecting soil compaction in comparison to the inflation pressure of tire.

• Journal of Bio-Environment Control
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• v.3 no.2
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• pp.128-135
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• 1994

Recently, regionally characterized greenhouses have been built every place around the country. These greenhouses insist of their higher performance by considering regional merits than the greenhouses without considering regional ones, but it is not clear. The purpose of this study was to make clear the characteristics of the regionally characterized greenhouses through the analyses of actual state and structural safety. The greenhouses were investigated and classified into wide span house, large pipe house, arched lattice house, wooden house, viniculture house, and domed pipe house. The frames of wide span house, arched truss house, viniculture house and domed pipe house were analyzed to be structurally stable under the design wind speeds and snow depths in recurrence intervals of 15 or 30 years, but large pipe house was a little unstable and required some reinforcements, and wooden house turned out to be unstable. In addition, foundations of all characterized greenhouses were stable against pull - out capacity under the design wind speeds in recurrence interval of 30 years.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.3
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• pp.225-231
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• 2017

This study was carried out for the production of aerial work machinery in high place in the orchard. In the case of orchards, there are many unpaved roads and sloping grounds to solve the problem of overturning or safety problems when working in a orchard. For more stable operation, an automatic leveling system was designed. During the structural analysis, the horizontal sensor was installed in addition to the standard that we wanted. Based on the INVENTOR, the structural analysis through 3D modeling showed that the maximum tilt of the worker was 116.49Mpa on the left and 118.26Mpa on the right.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.5
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• pp.37-45
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• 2010

Manure recycling as fertilizer is one of solutions for the environmental problem related with livestock manure treatment as well as the ocean dumping ban act prohibiting manure disposal to the ocean. For the manure disposal, forest area can be a candidate place because the area has a wide range of applicable sites. However, the manure application to the forest has a possibility of causing environmental impacts including water quality problems due to nutrient loading. Therefore it is necessary to investigate water quality impact from manure disposal to the forestry plantation. In this study, ground and soil water quality had been monitored in the bio-circulation experimental forest where low concentration liquid manure (LCLM) was applied. Soil and groundwater samples were collected and analyzed weekly from April to October in 2008 and 2009. The mean and variation of NO3-N concentration in soil water of LCLM treatment places showed higher concentration than the reference places declining during growing season. In the case of groundwater from monitoring well in the downstream of disposal site, the $NO_3$-N concentration was 3.59 mg/L in 2008 and 3.26 mg/L in 2009 in average showing higher concentration than the reference well although the concentration was not exceed the national drinking water standard. To investigate the source of nitrate, $\delta^{15}N$ isotope analysis was also implemented. Its result showed that the LCLM application could be the nitrate source requiring further long-term monitoring soil and water quality.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.1-10
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• 2002

This study was carried out to investigate experimentally the effect of three factors(dynamic load, inflation pressure and number of passes of tire) on soil compaction under the tire. The experiment were conducted with a 6.00R14 radial-ply tire for sandy loam soil using soil bin system. To evaluate the effect of three factors on soil compaction under the tire, the sinkage. density and volume of soil under the tire were measured fur the three levels of dynamic load(1.17kN, 2.35kN and 3.53kN), for the three levels of tire inflation pressure(103.42kPa, 206.84kPa and 413.67kPa), and for three different number of passes(1, 3 and 5). The results of this study can be summarized as follows : 1. As dynamic load, inflation pressure and number of passes of the tire increased, soil sinkage and density increased. and volume of soil decreased. Thus increase in dynamic load, inflation pressure and number of passes of the tire would increase soil compaction. 2. The effect of tire inflation pressure on sinkage. density and volume of soil under the tire was relatively less than that of the dynamic load. Therefore, it was concluded that dynamic load was more important factor affecting soil compaction in comparison to the inflation pressure of tire. 3. The effect of three different factors on sinkage, density and volume of soil decreased as the soil depth increase. Consequently, it was fecund that soil compaction at a shallow depth in soil was larger than that at deep place in soil.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.477-481
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• 2007

The emergency patient who occurs from the place where it is various the control which is quick must come to accomplish in Ubiquitous environment. In the body of the patient or the old person the organism signal sensor about under attaching condition of the patient at real-time about under the monitor ring about under disposing the control which is quick against the emergency patient does to become accomplished at the case real-time when the above will get in the body of the patient or the old person. Using ZigBee (802.15.4) system base on Shor wireless communication protocol because of complement wireless of hospital. This system use ZigBee (802.15.4) system to get for electrocardiogram, blood pressure and pulse bio-sensors. This paper constructs Bio-Sensor communication monitoring system and transmission rate and the delay which it follows possibility and node occurrence rate of wireless sensor network construction hour transmission session it leads and it verifies the effectiveness.