• Tunnel and Underground Space
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• v.34 no.4
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• pp.374-392
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• 2024

In order to successfully select a site for deep geological disposal of high-level radioactive waste, it is important to perform the stepwise approach along with the systematic selection and survey of evaluation parameters of geological environmental characteristics suitable for the domestic geological environment. In this study, we evaluated the characteristics of hydraulic conductivity, which is considered the most important evaluation parameter in the field of hydrogeology, targeting a deep-depth rock aquifer where actual disposal facilities are expected to be located. In particular, for the first time in Korea, we obtained in-situ pressure-flow data by directly conducting hydraulic tests in boreholes at depths ranging from 500 m to 750 m in various rock types distributed in Korea (granite/volcanic rock/gneiss/mudstone). And we derived hydraulic conductivity values by rock types and depth using verified analytical methods. For this purpose, precision hydraulic testing equipment developed in-house through this study was used, and detailed investigation procedures based on standard test methods were applied to field tests. As a result of the analysis, the average hydraulic conductivity value was found to be in the range of 10^-9 m/s in all granite/volcanic rock/gneiss areas. In the mudstone area, an average hydraulic conductivity value of 10^-11 m/s was derived, which was about 100 times (2 orders of magnitude) lower than that of the fractured rock aquifers. Moreover, permeability tended to slightly decrease with depth in fractured rock aquifers (granite and volcanic rock areas) containing many rock fractures. The gneiss area tended to have large local differences in permeability according to the composition of the stratum and the development of fracture zones rather than depth. In mudstone areas with weak fracture development, there was no significant variation in rock permeability according to depth. The hydraulic conductivity results by various rock types and depth presented in this study are expected to be utilized in building a foundational database for the site selection, design, and construction of disposal facilities in Korea.

• Journal of Korean Home Economics Education Association
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• v.15 no.3
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• pp.89-103
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• 2003

The purpose of this study was to investigate to relation of necessity and practice of contents of clothing and textiles education(classify them into four units, choice and dressing of clothes, textile and management of clothes, design and sewing of clothes, knitting and embroidery). Method of posing a questionnaire is adopted to obtain stochastic data required for pertinent analysis. This is the investigation of which 400 (high school students 204, university students 196) girl students located in Choongnam and Junrabookdo province. In this statistical analysis, SPSS 10.0 for Windows Program was utilized to calculate percentage, mean and standard deviation. Also, these materials were verified by t-test, One-way Anova, Pearson's correlation coefficient. The results of this research were as follows. First, girl students' necessity mean point were higher than practice mean point about the contents of clothing and textiles education. And necessity had a positive relationship with practices of contents of clothing and textiles education. Second, there was a significant difference in necessity and practice of contents of clothing and textiles education according to demographic variables. These results should be provide fundamental information for improving students' critical practice in their real life. Since this study has touched only limited research on the topic of clothing and textiles education, it is essential that further research covering a wider array of themes be done in the future. this study has touched only limited research on the topic of clothing and textiles education, it is essential that further research covering a wider array of themes be done in the future.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.56-68
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• 2009

Ongoing and extensive urbanisation, which is frequently accompanied with careless construction works, may threaten important archaeological structures that are still buried in the urban areas. Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods are most promising alternatives for resolving buried archaeological structures in urban territories. In this work, three case studies are presented, each of which involves an integrated geophysical survey employing the surface three-dimensional (3D) ERT and GPR techniques, in order to archaeologically characterise the investigated areas. The test field sites are located at the historical centres of two of the most populated cities of the island of Crete, in Greece. The ERT and GPR data were collected along a dense network of parallel profiles. The subsurface resistivity structure was reconstructed by processing the apparent resistivity data with a 3D inversion algorithm. The GPR sections were processed with a systematic way, applying specific filters to the data in order to enhance their information content. Finally, horizontal depth slices representing the 3D variation of the physical properties were created. The GPR and ERT images significantly contributed in reconstructing the complex subsurface properties in these urban areas. Strong GPR reflections and highresistivity anomalies were correlated with possible archaeological structures. Subsequent excavations in specific places at both sites verified the geophysical results. The specific case studies demonstrated the applicability of ERT and GPR techniques during the design and construction stages of urban infrastructure works, indicating areas of archaeological significance and guiding archaeological excavations before construction work.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.106-121
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• 2011

The number of World Natural Heritage Sites is smaller than that of World Cultural Heritage Sites. As of 2010, the total number of natural sites was 180, which is less than 1/3 of all cultural sites. The reason why the number of natural sites is smaller can be attributed to the evaluating criteria of OUV(outstanding universal value). Only 9 fossil related sites were designated as World Heritage Sites among 180 Natural Sites. This study compares their OUVs including the academic value and characteristics of the 9 World Heritage Sites to provide data and reference for KCDC(Korean Cretaceous Dinosaur Coast) to apply as a World Natural Heritage Site. This study was carried out to obtain information and data on the Wadi Al-Hitan of Egypt which was designated as a World Natural Heritage Site. The study includes field investigation for whale fossils, interviews of site paleontologists and staff, and inspections of facilities. Three factors can likely be attributed to its successful management and operating system. First, there is a system for comprehensive research and a monitoring plan. Secondly, experts have been recruited and hired and professional training for staff members has been done properly. Finally, the Wadi Al-Hitan has developed local resources with specialized techniques for conservation and construction design, which matched well with whale fossils and the environment at the site. The Wadi Al-Hitan put a master plan into practice and achieved goals for action plans. To designate a future World Natural Heritage Site in Korea, it is important to be recognized by international experts including IUCN specialists as the best in one's field with OUV. Full-time regular-status employees for a research position are necessary from the preparation stage for the UNESCO World Heritage Site. Local government and related organizations must do their best to control monitoring plans and to improve academic value after the UNESCO World Heritage Site designation. As we experienced during the designation process of Jeju Volcanic Island and Lava Tubes as the first Korean World Natural Heritage Site, participation by various scholars and specialists need to be in harmony with active endeavors from local governments and NGOs.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.439-450
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• 2023

Purpose: When conducting fire inspections in Korea, there are objects that violate the fire protection regulations that require a straight line distance of more than 5m between the air inlet and the discharge section if the floor area is less than 400m2, and this paper analyzes the reasons and conducts a model experimental study to support the need for related fire protection regulations. Method: Domestic firefighting objects were investigated and confirmed, domestic and foreign papers, policies, and laws and regulations were examined, and spaces with a straight line distance of less than 5m and more than 5m between the air inlet and discharge section were selected and analyzed through model experiments in a living room of less than 400m² . Result: When examining the domestic fire protection regulations (NFPCNational Fire Perpormance Code), the separation distance between the air inlet and the outlet is more than 5m when the floor area is less than 400m² , but as a result of the actual investigation, it was confirmed that there are firefighting objects that cannot keep the separation distance. In addition, when a paper review of overseas fire protection regulations for a straight line distance of more than 5m showed that there was no regulation on the straight line distance between the air inlet and the discharge section, the model experiment showed that the discharge speed was better when the straight line distance between the air inlet and the discharge section was more than 5m than when it was less than 5m. Conclusions: In this study, when examining overseas fire laws and regulations by comparing the performance of the fire protection ratio for the straight line distance between the air inlet and the exhaust section, there is no mandatory regulation for the straight line distance, but the domestic fire protection regulations (NFPCNational Fire Perpormance Code) require more than 5m. It is hoped that this will be reflected in the design stage in the future, and a foundation will be laid to reduce the responsibility and burden of fire superintendents.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.3
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• pp.3860-3871
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• 1975

This experiment was carried out to establish the mechanized methods in stumping and root-clearing, which were the most important works in the reclamation of sloping uplands. The determination of optimum teeth interval of rake blades and its operation methods to reduce the quantity of transported topsoil during the works, are the aims of this investigation. A newly designed rake blade, whose net teeth intervals could be regulated by three stages as 15cm, 25cm, and 35cm, was manufactured to attach to the bulldozer of 13ton. The experiments were carried out at Kilsang-Myon, Kwangwha-Gun, from Aug. 9 to Aug. 23, 1975. For each interval, 36 test plots of 50${\times}$10mn in size, which were regulated under three levels of land slopes of 10, 20, and 30% and two different tree stand density of high or medium values, were randomly chosen and arranged by two-replicated split-split plot design. Each stump classified by its diameter was stumped and cleared by the rake dozer to be related between diameter and stumping time. The results obtained in this experiment can be summarized as follows: 1. Stumping times for the diameters ranging from 6 to 18cm of stumps are almost the same and they are not varied by the difference of teeth intervals of rake dozer. 2. By back-ward stumping method, the number of stumps which can be stumped per hour ranges almost from 100 to 170, showing significant difference with respect to the teeth intervals. The working area is sharply varied with not only the stand density of stumps but the teeth intervals. 3. Optimum stumping distance for each teeth interval of rake dozer to minimize the quantity of transported topsoil are varied with such the rates as it is 15m or 20m for 15cm of teeth interval, but 25m for 25cm or 35cm, respectively. The clearing distance could be chosen almost double as long as the operating distance. 4. The working areas per hour of the simultaneous stumping and clearing methods are no significant difference among the various treatments of working conditions, but they are affected by the operating techniques. However, the influencing factors of the working conditions as classified before and the working directions are ranged from 10 to 15 per cent of total working area, respectively. 5. The residual rates of stumps which are not stumped by the rake dozer in each test plot are generally reduced as the teeth interval gets narrower, but there are no significant difference among them. The mean residual rates average to be about 4% for the simultaneous stumping and clearing method. The back-ward stumping method are recommended to be supervised and directed by more than one man, to show the operator where the stumps are located. 6. The results according to the stumping and clearing methods are summarized as Table IV-2. And the selection of working methods is recommended to follow as shown in Fig. IV-9 with respect to the stand density of the field. 7. Generally speaking, the narrower the teeth interval, the better become the working results, but the more the quantity of transported topsoil is increased. Therefore, it is recommended that the teeth interval should be reduced from the present distance of more than 30cm to 25cm or 15cm, by developing suitable working methods through more field works and experiments.

• Journal of Biosystems Engineering
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• v.1 no.1
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• pp.1-6
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• 1976

This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

• Korean Security Journal
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• no.41
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• pp.37-66
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• 2014

In recent years, with the development of computers and electronics, electronics and communication technology in a growing and each part is dependent on the cross-referencing makes all electronic equipment is obsolete due to direct or indirect damage EMP. Korea and the impending standoff North Korea has a considerable level of technologies related to the EMP, EMP weapons you already have or in a few years, the development of EMP weapons will complete. North Korea launched a long-range missile and conducted a nuclear test on several occasions immediately after, when I saw the high-altitude nuclear blackmail has been strengthening the outright offensive nuclear EMP attacks at any time and practical significance for the EMP will need offensive skills would improve. At this point you can predict the damage situation of Korea's security reality that satisfy the need, more than anything else to build a protective system of the EMP. The scale of the damage that unforeseen but significant military damage and socio-economic damage and fatalities when I looked into the situation which started out as a satellite communications systems and equipment to attack military and security systems and transportation, finance, national emergency system, such as the damage elsewhere. In General, there is no direct casualties reported, but EMP medical devices that rely on lethal damage to people who can show up. In addition, the State power system failure due to a power supply interruption would not have thought the damage would bring State highly dependent on domestic power generation of nuclear plants is a serious nuclear power plant accident in the event of a blackout phenomenon can lead to the plant's internal problems should see a forecast. First of all, a special expert Committee of the EMP, the demand for protective facilities and equipment and conduct an investigation, he takes fits into your budget is under strict criteria by configuring the contractors should be sifting through. He then created the Agency for verification of performance EMP protection after you have verified the performance of maintenance, maintenance, safety and security management, design and construction company organized and systematic process Guard facilities or secret communications equipment and perfect for the EMP, such as protective equipment maneuver system should take.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.107-116
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• 2000

This study is of investigation of refraction error, spectacles and contact lenses wearing state, visual acuity test, ophthalmologic common sense and vision care, using questionnaire study for 850 male and female high school students in Kunsan and Chongup City, Cheolla North Province. The results are as follows: 1. Among the 823 answerers, emmetropia is 18%, myopia is 55.1%, and hyperopia is 7%, respectively. 2. Among the 837 answerers, 381 students(45.5%) wear spectacles or contact lenses. Among the 381 students who wear spectacles or contact lenses, 78% wear only spectacles, 4% wear only contact lenses and 18% wears spectacles sometimes or contact lenses sometimes. 3. The places where the answerers had visual acuity test to wear spectacles or contact lenses are optical shop(64.7%), hospital(28.3%), unchecked(4.2%) and the others(2.7%). The places where the answerers had visual acuity test to change their spectacles or contact lenses are optical shop(82%), hospital(28.3%), unchecked(6.6%) and the others(1.9%). 4. As for the period of visual acuity test, from 6 months to one year is 54.1%, within 6 months is 9.2%, from one year to two years is 29.5%, and more than two years is 7.2%. 5. The contact lens wearers purchased their contact lenses at optical shops(94%) and at hospital(6%). 6. The reasons why they like wearing contact lenses are their appearance(51.2%), convenience in physical excercise(23.l%), lighter weight than spectacles(9.8%) and the others(15.7%). 7. As for the spectacles frame they like, plastic frame is 24.4%, gold or silver plated frame is 43.4%, coloured frame is 32.1%. 8. As for the considerations in choosing spectacles frame, their design is 37%, their quality is 36%, their price is 14.7% and their brand is 12.5%. 9. As for the period for changing spectacles, 10.5% is within 6 months, 57.3% is 6months to 1 year, 22.4% is 1 year to 2 months and 9.6% is more than 2 years. 10. There is a false fact, in Korea, that even though one has his poor eyesight, not wearing custom is helpful for the eyesight recovery. As for their conviction of the false fact, 10.5% of the answerers have 100% conviction, 22.5% of them have 22.5% conviction, 49.5% of them have 50% conviction and 17.5% of them don't have any conviction. 11. 48.5% of the answerers are interested in their vision care while 51.5% of them are not interested at all. As for the way of vision care, the vision-care way to keep enough distant when they are watching TV, when they are using computers and when they are reading, is 49% while the vision-care way such as hypogastric breathing or eye massage is 11%. And alimentotherapy is 4% and the rest who are not interested in vision care is 36%. 12. When they come to an age, the students who want vision correction operation are 45.9% while the students who do not want it are 27%. The students who do not have any idea about the operation are 27.1%

• Geophysics and Geophysical Exploration
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• v.11 no.3
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• pp.250-262
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• 2008

In order to assess the feasibility of the dipole-dipole electric method to the investigation of metallic ore deposit, both field data simulation and inversion are carried out for several simplified ore deposit models. Our interest is in a vein-type model, because most of the ore deposits (more than 70%) exist in a vein type in Korea. Based on the fact that the width of the vein-type ore deposits ranges from tens of centimeters to 2m, we change the width and the material property of the vein, and we use 40m-electrode spacing for our test. For the vein-type model with too small width, the low resistivity zone is not detected, even though the resistivity of the vein amounts to 1/300 of that of the surrounding rock. Considering a wide electrode interval and cell size used in the inversion, it is natural that the size of the low resistivity zone is overestimated. We also perform field data simulation and inversion for a vein-type model with surrounding hydrothermal alteration zones, which is a typical structure in an epithermal ore deposits. In the model, the material properties are assumed on the basis of resistivity values directly observed in a mine originated from an epithermal ore deposits. From this simulation, we can also note that the high resistivity value of the vein does not affect the results when the width of the vein is narrow. This indicates that our main target should be surrounding hydrothermal alteration zones rather than veins in field survey. From these results, we can summarize that when the vein is placed at the deep part and the difference of resistivity values between the vein and the surrounding rock is not large enough, we cannot detect low resistivity zone and interpret the subsurface structures incorrectly using the electric method performed at the surface. Although this work is a little simple, it can be used as references for field survey design and field data Interpretation. If we perform field data simulation and inversion for a number of models and provide some references, they will be helpful in real field survey and interpretation.