• Journal of the Korean earth science society
• /
• v.39 no.3
• /
• pp.250-259
• /
• 2018

We investigated the petrological features of the stone materials used in the Jeolla Usuyeong rampart and estimated their provenance through the geological survey. The Jeolla Usuyeong was designated as a historic site (No. 535) on 2016. Since the remaining rampart is less than 15%, it is necessary to make conservation on it. In this study, we discriminated the stone materials used for the rampart according to their petrographic characteristics and estimated the volume proportion of each stone by the rock type. Also, we measured the whole-rock magnetic susceptibility. The petrographic features of the stones in the rampart were compared with those in the vicinity by their mineral composition and texture. The stone materials of the rampart mainly consist of the tuff, lapilli tuff, and lapilli stone. Among these three kinds of rocks, lapilli tuff is quantitatively the most abundant (60.3%), the next is tuff (34.7%), and lapilli stone (2.5%) shows the least amount. The whole-rock magnetic susceptibility of the tuffaceous rocks can be divided by the value of $1.0{\times}10^{-3}$ SI unit. Also, the compressive strength of tuff exhibits about 156 MPa, which is adequate to reuse for the repairing work. Petrological comparisons between stone materials and outcrop rocks distributed around the Hwawon peninsula leads to a conclusion that the stone materials of the rampart are likely to have been delivered from the Dongoeri and Sindeok-ri. Judging from the results of the comparison on the frequency of use and physical properties among the tuffaceous rocks, tuff is considered to suitable for restoring the rampart.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.5 no.1
• /
• pp.30-36
• /
• 1999

Physical analysis of some composite films of outer packaging at process cheeses in Korea is as following. In comparison with four composite films, tensile strength is $72.2{\mu}PET/PVDC/PE/AL-vac/PE\;film\;MD9.55kg/15mm,\;TD8.95kg/15mm>79.3{\mu}PET/PVDC/L-LDPE\;film\;MD5.37kg/15mm,\;TD5.01kg/15mm>96.9{\mu}PE/PVDC/PE\;film\;MD5.42kg/15mm,\;TD4.73kg/15mm>61.6{\mu}PVDC/PE/AL-vac/CPS\;film\;MD4.65kg/15mm,\;TD4.22kg/15mm$. Water vapor transmission is $72.2{\mu}PET/PVDC/PE/AL-vac/PE\;film\;0.41g/m^2{\cdot}24hr>79.3{\mu}PET/PVDC/L-LDPE\;film\;3.77g/m^2{\cdot}24hr>96.9{\mu}PE/PVDC/PE\;film\;3.81g/m^2{\cdot}24hr>61.6{\mu}PVDC/PE/AL-vac/4.91g/m^2{\cdot}24hr$. Gas transmission $O_2:N_2:CO_2$ is $72.2{\mu}PET/PVDC/PE/AL-vac/PE\;film\;1.81:0.74:4.2cc/m^2{\cdot}24hr{\cdot}atm>79.3{\mu}PET/PVDC/L-LDPE\;film\;13.4:6.4:34.2cc/m^2{\cdot}24hr{\cdot}atm>96.9{\mu}PE/PVDC/PE\;film\;15.3:7.1:42.0cc/m^2{\cdot}24hr{\cdot}atm>61.6{\mu}PVDC/PE/AL-vac/CPS\;film\;25.3:12.5:59.3cc/m^2{\cdot}24hr{\cdot}atm$ each other. And for preservation this were sealed to filths $N_2,\;CO_2$ gas or defilling ai (vacuum type) in the packaging and reserved less than $10^{\circ}C$ at refrigerator.

• Restorative Dentistry and Endodontics
• /
• v.14 no.1
• /
• pp.41-56
• /
• 1989

The purpose of this study was to examine the effect of temperature dependence of the behavior on the physical properties of posterior composite resins. Three light cure posterior composite resins (Heliomolar, Litefil-P, and P-50) and one chemical cure posterior composite resin (Bisfil-II) were used as experimental materials. Composite resin was placed in a cylindrical brass mold (2.5 mm high and 6.5 mm inside diameter) that was rested on a glass plate. Another flat glass was placed on top of the mold, and the plate was tightly clamped together. After the mold had been filled with the light cure composite material, the top surface was cured for 30 seconds with a light source. Chemical cure resin specimens were made in the same manner as above. Three hundreds and twenty composite resin specimens were constructed from the four composite materials. One hundred and sixty specimens of them were placed in a heater at $50^{\circ}C$, $75^{\circ}C$, $100^{\circ}C$, $125^{\circ}C$, $150^{\circ}C$, $175^{\circ}C$ and $200^{\circ}C$ for 5 minutes or 10 minutes respectively before compressive strengths were measured. Another one hundred and sixty specimens were tested for the diametral tensile strengths in the same way as above. They were randomly divided into eight groups according to the mode of heating methods as follows and stored in distilled water at $37^{\circ}C$ for 24 hours. Group $37^{\circ}C$ - specimens were stored at $37^{\circ}C$ in distilled water for 24 hours. Group $50^{\circ}C$ - specimens were heated at $50^{\circ}C$ after curing. Group $75^{\circ}C$ - specimens were heated at $75^{\circ}C$ after curing. Group $100^{\circ}C$ - specimens were heated at $100^{\circ}C$ after curing. Group $125^{\circ}C$ - specimens were heated at $125^{\circ}C$ after curing. Group $150^{\circ}C$ - specimens were heated at $150^{\circ}C$ after curing. Group $175^{\circ}C$ - specimens were heated at $175^{\circ}C$ after curing. Group $200^{\circ}C$ - specimens were heated at $200^{\circ}C$ after curing. Twenty specimens of each of four composite resins were respectively made by insertion of materials into same mold for examining the dimensional changes between before and after heating. The final eighty specimens were stored in distilled water at $37^{\circ}C$ for 24 hours before testing the dimensional changes. Compressive and diametral tensile strengths were measured crosshead speed 1mm/minute and 500Kg in full scale with a mechanical testing machine (DLC 500 Type, Shimadzu Co., Japan). Dimensional changes were determined by measuring the diametral changes of eighty specimens with micrometer (Mitutoyo Co., Japan). Results were as follows: 1. Diametral tensile strengths of specimens in all groups were increased with time heated compared with control group except for that in group $50^{\circ}C$ and the maximum diametral tensile strength was appeared in the specimen of Litefil-P heated for 10 minutes at $100^{\circ}C$. In heliomolar and P-50, it could be seen in the specimen heated for 10 minutes at $150^{\circ}C$, but in Bisfil-II, it could be found in the specimen heated for 5 minutes at $150^{\circ}C$. 2. Compressive strengths of specimens in all groups was tended to be also increased with time heated but that in group $50^{\circ}C$ and the maximum compressive strengths were showed in the same specimens conditioned as the diametral tensile strengths of four composite materials tested. 3. In Heliomolar, Litefil-P, and Bisfil-II, it was decreased in diameters of resin specimens between before heating and increased in diameters of resin specimens after storing in distilled water, but it was not in P-50. 4. There is little difference in diametral tensile strengths, compressive strengths, and dimensional changes followed by heating the resin specimens for 5 minutes and 10 minutes, but there is no statistical significances.

• Korean Security Journal
• /
• no.23
• /
• pp.65-86
• /
• 2010

The conclusion for this paper is as following as to plan for advancing security. First, Depending on situation, security martial arts technique is necessary in security work, but the case that the client need to be covered by security guards to avoid the danger often happens. If there is no self-sacrifice and loyalty to the clients, the meaningful security work is not completed in this situation. Therefore, the basic views on education of security leaders need to be defensive than aggressive, and be spirit-equipped than technical feature. Second, more time has to be taken training mentality along with focusing on technical education of security martial arts. To escape from danger spreaded around, security guards must be strong mentally and physically, then they are able to finish the situation. If someone is chosen as a security guard, one's physical strength is already approved. This means that the rest part for the perfect accomplishment is strict discipline on mental one's mind, and basically physical training has to be continued. In conclusion, The elements that the instructor has to acquire are not only extensive theoretical knowledge of the security martial arts and real experiences through techniques but also personality cultivation which maximize the morality training. Accordingly, this could bring the client personally change in perception of the security guard, furthermore greatly expand the academic and professional security work of security department.

• The korean journal of orthodontics
• /
• v.31 no.1 s.84
• /
• pp.149-157
• /
• 2001

The purpose of this study was to investigate the property of a new Korean stainless steel wire(Jinsung Ind.) comparing with other foreign Products. Five types of stainless steel wires (Standard, Resilient, HI-T of Unitek, Stainless steel of Ormco and Jinsung Ind.) in 0.016x0.022 and 0.019x0.02 were tested to observe for Composition analysis, size difference, tensile properties, flexure bending property, tortion property, surface hardness and surface topography by means of SEM. The findings suggest that: 1. In maximum tensile strength of tensile properties, Unitek Hi-T showed the greatest value, followed by Unitek Resilient, Jinsung Stainless Steel, Ormco Stainless Steel, Unitek Standard in 0.016x0.022, and Unitek Hi-T showed highest value, followed by Jinsung Stainless Steel, Ormco Stainless Steel, Unitek Resilient, Unitek Standard in 0.019x 0.025. 2. In elongation rate, Unitek Standard showed the greatest value, fellowed by Ormco Stainless Steel, Unitek Hi-T, Unitek Resilient, Jinsung Stainless Steel in 0.016x0.022, and Unitek Hi-T showed the highest value, followed by Unitek Standard, Ormco Stainless Steel, Jinsung Stainless Steel, Unitek Resilient in 0.019x0.025. 3. In modulus of elasticity, Jinsung Stainless Steel showed the greatest value, followed by Unitek Hi-T, Unitek Resilient, Ormco Stainless Steel, Unitek Standard in 0.016x0.022, and Unitek Resilient showed the highest value followed by Jinsung Stainless Steel, Ormco Stainless Steel, Unitek Hi-T, Unitek Standard in 0.019x0.025. 4. In bending fatigue test, Jinsung Stainless Steel showed the greatest fracture resistance, followed by Unitek Hi-T, Unitek Standard, Unitek Resilient, Ormco Stainless Steel in 0.016x0.022, and Unitek Hi-T showed the greatest fracture resistance followed by Jinsung Stainless Steel, Unitek Resilient, Unitek Standard, Ormco Stainless Steel in 0.019x0.025. 5. In twist test, Unitek Resilient showed the greatest fracture resistance, followed by Jinsung Stainless Steel, Unitek Hi-7, Ormco Stainless Steel, Unitek Standard in 0.016x0.022, and Jinsung showed the greatest fracture resistance, followed by Unitek Resilient, Unitek Standard, Ormco Stainless Steel, Unitek Hi-T. 6. In surface topography, every products showed indentation and pitting. Jinsung stainless steel wire showed long thin indentation and relatively smooth surface. Unitek wires showed indentation and pitting and Ormco wire showed a lot of irregular pittings.

• Journal of Korean Society of Forest Science
• /
• v.89 no.3
• /
• pp.323-334
• /
• 2000

This study was carried out to investigate the effects of geological and topographical features on landslide and land-creep at the twenty four surveyed sites of Kyungpook province. According to the results obtained, it was concluded that continuous heavy rainfall was one of the primary factors to occur landslide and land-creep. Most of the landslides occurred in the past were concentrated in the granite and granitic gneiss zones, while land-creeps were mainly occurred in the mud-stone zones. Therefore, it was thought that the physical properties such as soil texture, solid phase, moisture contents, density, hardness and porosity rate of weathered granite and granitic gneiss could affect the occurrence of landslide and land-creep. Due to the holding of sand contents in the upper soil layers of weathered granite and granitic gneiss, rainfall could infiltrate into the soil easily. While lower soil layers contained much quantity of clay and silt contents, those soils saturated with rainfall cause to lose viscosity and shear strength. Therefore, it was seemed that landslide was occurred more easily and the saturation of those soils was made much easily by bed rocks under those soils. Landslide and land-creep are slided into lower place by gravitation and slope degree factors. Therefore, prediction of landslide occurrence is very difficult because landslide is occurred abruptly, and physical properties of the soil have to be understood and checking the existence of bed rocks under the soils is not easy, on the other hand, land-creep is progressed very slowly. Therefore, it was suggested that in a degree creeping could be protected by removing of several causing factors.

• The KIPS Transactions:PartC
• /
• v.13C no.1 s.104
• /
• pp.83-94
• /
• 2006

This paper describes ATM cell encipherment method using Rijndael Algorithm adopted as an AES(Advanced Encryption Standard) by NIST in 2001. ISO 9160 describes the requirement of physical layer data processing in encryption/decryption. For the description of ATM cell encipherment method, we implemented ATM data encipherment equipment which satisfies the requirements of ISO 9160, and verified the encipherment/decipherment processing at ATM STM-1 rate(155.52Mbps). The DES algorithm can process data in the block size of 64 bits and its key length is 64 bits, but the Rijndael algorithm can process data in the block size of 128 bits and the key length of 128, 192, or 256 bits selectively. So it is more flexible in high bit rate data processing and stronger in encription strength than DES. For tile real time encryption of high bit rate data stream. Rijndael algorithm was implemented in FPGA in this experiment. The boundary of serial UNI cell was detected by the CRC method, and in the case of user data cell the payload of 48 octets (384 bits) is converted in parallel and transferred to 3 Rijndael encipherment module in the block size of 128 bits individually. After completion of encryption, the header stored in buffer is attached to the enciphered payload and retransmitted in the format of cell. At the receiving end, the boundary of ceil is detected by the CRC method and the payload type is decided. n the payload type is the user data cell, the payload of the cell is transferred to the 3-Rijndael decryption module in the block sire of 128 bits for decryption of data. And in the case of maintenance cell, the payload is extracted without decryption processing.

• The Journal of Engineering Geology
• /
• v.18 no.4
• /
• pp.447-457
• /
• 2008

Laboratory tests for single plane sliding were conducted using the model rock slope to investigate the cut slope deformability and failure mechanism due to combined effect of engineering characteristics such as angle of sliding plane, water force, joint roughness and infillings. Also the possibility of prediction of slope failure through displacement monitoring was explored. The joint roughness was prepared in forms of saw-tooth type having different roughness specifications. The infillings was maintained between upper and lower roughness plane from zero to 1.2 times of the amplitude of the surface projections. Water force was expressed as the percent filling of tension crack from dry (0%) to full (100%), and constantly increased from 0% at the rate of 0.5%/min and 1%/min upto failure. Total of 50 tests were performed at sliding angles of $30^{\circ}$ and $35^{\circ}$ based on different combinations of joint roughness, infilling thickness and water force increment conditions. For smooth sliding plane, it was found that the linear type of deformability exhibited irrespective of the infilling thickness and water force conditions. For sliding planes having roughness, stepping or exponential types of deformability were predominant under condition that the infilling thickness is lower or higher than asperity height, respectively. These arise from the fact that, once the infilling thickness exceeds asperities, strength and deformability of the sliding plane is controlled by the engineering characteristics of the infilling materials. The results obtained in this study clearly show that the water force at failure was found to increase with increasing joint roughness, and to decrease with increasing filling thickness. It seems possible to estimate failure time using the inverse velocity method for sliding plane having exponential type of deformability. However, it is necessary to estimate failure time by trial and error basis to predict failure of the slope accurately.

• Economic and Environmental Geology
• /
• v.37 no.3
• /
• pp.355-364
• /
• 2004

A study on the weathering grade classification has been performed for granite and granite gneiss in Korea. The qualitative classification criteria of weathering were reviewed and then modified with field studies for the weathered rock masses. The thin section observations and XRD analyses for the different weathering grades rock samples showed the petrographical and petrophysical difference with respect to the weathering : the proportion of weathering-resistant minerals suck at quartz and orthoclase has a tendency to increase with the development of weathering, but that of weathering-sensible minerals such as anorthite and biotite is decreased. The ranges of physical and mechanical rock properties for different weathering grades were obtained from the laboratory rock tests and field tests for the studied rocks. And then, along with $RDI_{sq}$(Fookes et al., 1988), the weathering index $I_{a}$, (Woo, 2003) has been developed in this study to demarcate the weathering grade. Those two indices rely mainly on the water absorption ratio of rock and on the different rock strength. The range of these weathering indices have been determined with the physical and mechanical rock properties that can be obtained from simple field or laboratory tests in 4 grades $I_{a}$＞ 7 for F, 3.5 ＜ $I_{a}$ ＜ 10 for SW, 1.0 $I_{a}$＜ 6.0 for MW and $I_{a}$＜ 2.5 for HW. Consequently, the weathering index could be utilized to classify quantitatively the rock weathering grade, especially for the studied granites and the granite gneiss in Korea.

• 한국노년학
• /
• v.30 no.4
• /
• pp.1293-1309
• /
• 2010

This study is aimed to evaluate the effects of community-based prehabilitation program developed to prevent functional decline in the frail elderly and to provide a basis to practically operate this program in the public health care service. From March to August 2009, 110 frail elderly people were recruited among the registered participants of the home visit program in Korea to perform a prospective randomized community trial. We randomly assigned these people into two groups. One group (n=50) participated in the visiting prehabilitation program for 3 months focusing on improving their muscle strength of upper and lower limbs, walking ability, and balancing. The other group (n=60) underwent our visiting fall prevention program for control. To assess the effectiveness of prehabilitation program, physical functioning (PF) and short physical performance battery (SPPB) were measured for the primary outcomes and also some other indicators: exercise performance, nutritional status, emotional functioning, experience of admission, and events of fall. As a result, significant improvements of geriatric functional status were noticed among the participants. After 3 months, PF increased by 1.3 ± 3.8 points in prehabilitation group and decreased by 1.1 ± 5.4 points in controls (p=.020). SPPB improved by 2.4 ± 2.0 points in prehabilitation group and increased only 0.3 ± 1.5 points in controls (p<.001). Significant effects were also shown in their exercise performance tests and emotional status, the number of multiple falls, and the experience of functional decline after the fall (p .002-.038). Visiting prehabilitation program is safe and effective program for frail older adults. Thus, it is strongly recommended to universally adopt this program to prevent functional decline in the frail elderly.