• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.307-317
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• 2002

In this paper we propose a new mesh reconstruction scheme that produces a displaced subdivision surface directly from unorganized points. The displaced subdivision surface is a new mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface, but original displaced subdivision surface algorithm needs an explicit polygonal mesh since it is not a mesh reconstruction algorithm but a mesh conversion (remeshing) algorithm. The main idea of our approach is that we sample surface detail from unorganized points without any topological information. For this, we predict a virtual triangular face from unorganized points for each sampling ray from a parameteric domain surface. Direct displaced subdivision surface reconstruction from unorganized points has much importance since the output of this algorithm has several important properties: It has compact mesh representation since most vertices can be represented by only a scalar value. Underlying structure of it is piecewise regular so it ran be easily transformed into a multiresolution mesh. Smoothness after mesh deformation is automatically preserved. We avoid time-consuming global energy optimization by employing the input data dependant mesh smoothing, so we can get a good quality displaced subdivision surface quickly.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.59-68
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• 2016

The application of the Life Cycle Assessment (LCA) methodology to assess the environmental impact of rapeseed cultivation in winter fallow after harvesting rice was investigated and compared with barley cultivation in crop rotation system. Data for input materials were collected and analyzed by 1 ton rapeseed and barley as functional unit. For the Life Cycle Impact Assessment (LCIA) the Eco-indicator 95 method has been chosen because this is well documented and regularly applied impact method. From the comparison of impact categories such as greenhouse effect, ozone depletion, acidification, heavy metals, carcinogens, summer smog, and energy resources for 1 ton of final product, emission potential from rapeseed was higher than that from barley. The range from 65 to 96% of these potential came from chemical fertilizer. On the other hand, eutrophication potential from barley was higher than that from rapeseed, mainly came from utilizing the chemical fertilizer. During the cultivation of barley and rape, environmental burden by heavy metals was evaluated by 0.5 Pt, larger than points from other impact categories. The sum of points from all impact categories in barley and rapeseed was calculated to be 0.78 Pt and 0.82 Pt, respectively. From the sensitivity analysis for barley and rapeseed, scenario 1 (crop responses to fertilization level) showed the environmental burden was continuously increased with the amount of fertilization in barley cultivation, while it was not increased only at the optimum crop responses to fertilization in rapeseed (R3). With these results, rapeseed cultivation in winter fallow paddy contributed to the amounts of environmental burden much more than barley cultivation. It is, however, highly determined that environmental weighted point resulted from evaluating both cultivation was not significantly different.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.451-466
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• 2009

While substorms are known to generally occur under southward IMF conditions, they can sometimes occur even under northward IMF conditions. In this paper, we studied the substorms that occurred in May, 2000 to 2002 to examine some statistical characteristics of the IMF and solar wind associated with northward IMF substorms. We focused on the cases where two or more substorms occurred successively under northward IMF conditions. Also, by checking Sym-H index associated with each of the substorms we determined whether or not there is any association of such northward IMF substorm occurrence with storm times. We also examined statistical properties at geosynchronous altitude in terms of magnetic field dipolarization and energetic particle injection. The following results were obtained. (i) Most of the northward IMF substorms occurred under average solar wind conditions. The majority of them occurred within 2 hrs duration of northward IMF Bz state, but there are also a nonnegligible number of substorms that occurred after a longer duraiton of northward IMF Bz state. (ii) While most of the substorms occurred as isolated from a magnetic storm time, those that occurred in a magnetic storm time show a higher average value of IMF and solar wind than that for the isolated substorms. (iii) About 55% of the substorms were associated with the IMF clock angle that can possibly allow dayside reconnection, and the other 45% were associated with more or less pure northward IMF conditions. Therefore, for the latter cases, the energy input from the solar wind into the magnetosphere should be made by other way than the dayside reconnection. (iv) For most of the substorms, the magnetic field dipolarizations and energetic particle injections at geosynchronous altitude were identified to be generally weak. But, several events indicated strong magnetic field dipolarizations and energetic particle injections.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.424-429
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• 2010

To solve the problems with excessive accumulation of soil inorganic N and resulting saline soils from overuse of nitrogen fertilizer, the effect of sucrose application on decrease of soil inorganic N content and electrical conductivity (EC) was studied. Sucrose treatment greatly reduced ${NH_4}^+$-N content in soil. The amount of reduction was greater as the amount of sucrose treatment was increased. When ${NH_4}^+$-N content was reached the lowest point (about 10 mg $kg^{-1}$or lower), the C/N ratio, which determines the amount of sucrose treatment, was around 10 regardless of initial ${NH_4}^+$-N content. For the rate of ${NH_4}^+$-N reduction 15~36 hours was required to reduce the initial ${NH_4}^+$-N content to half, and 36~69 hours to lower ${NH_4}^+$-N content to the lowest point (about 10 mg $kg^{-1}$or lower). In addition, sucrose treatment greatly lowered ${NO_3}^-$-N content. In case of C/N ratio above 10, initial ${NO_3}^-$-N content of 348 mg $kg^{-1}$ was reduced to the lowest of 14~21 mg $kg^{-1}$. As for the rate of ${NO_3}^-$-N reduction by sucrose treatment, it took 36~60 hours for ${NO_3}^-$-N content to reach the lowest point for C/N ratio of 10 or higher, and it took 3 weeks, comparably longer time, for C/N ratio of 5. Lowering soil EC from sucrose treatment showed the same trend as ${NO_3}^-$-N content. As an important energy and carbon source for humankind, sugar should not be wasted and must be carefully applied to soil. In principle, the best way of preventing salt accumulation in soil is to optimize the fertilizer input. However, when over-fertilization should be dealt with, the sucrose treatment would be a possible and effective counter-measure to reduce overdosed nitrogen sources in soil.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.119-128
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• 2011

The Sensor technology and portable device capability able to collect recent user information and the information about the surrounding environment haven been highly developed. A user can be made use of various contents and the option is also extending with this technology development. In particular, the initial portable device had simply a call function, but now that has evolved into 'the 4th screen' which including movie, television, PC ability. also, in the past, a portable device to provided only the services of a SMS, in recent years, it provided to interactive video service, and it include technology which providing various contents. Also, it is rising as media which leading the consumption of contents, because it can be used anytime, anywhere. However, the contents available for the nature of user's handheld devices are limited. because it is very difficult for making the contents separately according to various device specification. To find a solution to this problem, the study on one contents from several device has been progressing. The contents conversion technology making use of the profile of device out of this study comes to the force and profile study has been progressing for this. Furthermore, Demand for a user is also increased and the study on the technology collecting, analyzing demands has been making active progress. And what is more, Grasping user's demands by making use of this technology and the study on the technology analyzing, providing contents has been making active progress as well. First of all, there is a method making good use of ZigBee, Bluetooth technology about the sensor for gathering user's information. ZigBee uses low-power digital radio for wireless headphone, wireless communication network, and being utilized for smart energy, automatic home system, wireless communication application and wireless sensor application. Bluetooth, as industry standards of PAN(Personal Area Networks), is being made of use of low power wireless device for the technology supporting data transmission such as drawing file, video file among Bluetooth device. With analyzing the collected information making use of this technology, it utilizes personalized service based on network knowledge developed by ETRI to service contents tailor-made for a user. Now that personalized service builds up network knowledge about user's various environments, the technology provides context friendly service constructed dynamically on the basis of this. The contents to service dynamically like this offer the contents that it converses with utilizing device profile to working well. Therefore, this paper suggests the system as follow. It collects the information, for example of user's sensitivity, context and location by using sensor technology, and generates the profile as a means of collected information as sensor. It collects the user's propensity to the information by user's input and event and generates profile in the same way besides the gathered information by sensor. Device transmits a generated profile and the profile about a device specification to proxy server. And proxy server transmits a profile to each profile management server. It analyzes profile in proxy server so that it selects the contents user demand and requests in contents server. Contents server receives a profile of user portable device from device profile server and converses the contents by using this. Original source code of contents convert into XML code using the device profile and XML code convert into source code available in user portable device. Thus, contents conversion process is terminated and user friendly system is completed as the user transmits optimal contents for user portable device.

• KSBB Journal
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• v.23 no.1
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• pp.90-95
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• 2008

In this study, a combined process of sequential anaerobic-aerobic digestion (SAAD), fluidized-bed bioreactor (FBBR), and ultrafiltration (UF) for the treatment of small scale food waste leachate was developed and evaluated. The SAAD process was tested for performance and stability by subjecting leachate from food waste to a two-phase anaerobic digestion. The main process used FBBR composed of aerators for oxygen supply and fluidization, three 5 ton reaction chambers containing an aerobic mesophilic microorganism immobilized in PE (polyethylene), and a sedimentation chamber. The HRTs (hydraulic retention time) of the combined SAAD-FBBR-UF process were 30, 7, and 1 day, and the operation temperature was set to the optimal one for microbial growth. The pilot process maintained its performance even when the CODcr of input leachate fluctuated largely. During the operation, average CODcr, TKN, TP, and salt of the effluent were 1,207mg/L, 100mg/L, 50 mg/L, and 0.01 %, which corresponded to the removal efficiencies of 99.4%, 98.6%, 89.6%, and 98.5%, respectively. These results show that the developed process is able to manage high concentration leachate from food waste and remove CODcr, TKN, TP, and salt effectively.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.55-62
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• 2006

Transverse cracks in continuously reinforced concrete pavement (CRCP) occur at early ages due to temperature and moisture variations. The width and spacing of transverse cracks have a significant effect on pavement performance such as load transfer efficiency and punchout development. Also, crack widths in CRCP depend on 'zero-stress temperature,' which is defined as a temperature where initial concrete stresses become zero, as well as drying shrinkage of concrete. For good long-term performance of CRCP, transverse cracks need to be kept tight. To keep the crack widths tight throughout the pavement life, zero-stress temperature must be as low as practically possible. Thus, temperature control at early ages is a key component In ensuring good CRCP performance. In this study, concrete temperatures were predicted using PavePro, a concrete temperature prediction program, for a CRCP construction project, and those values were compared with actual measured temperatures obtained from field testing. The cracks were also surveyed for 12 days after concrete placement. Findings from this study can be summarized as follows. First, the actual maximum temperatures are greater than the predicted maximum temperature in the ranges of 0.2 to 4.5$^{\circ}C$. For accurate temperature predictions, hydration properties of cementitious materials such as activation energy and adiabatic constants, should be evaluated and accurate values be obtained for use as input values. Second, within 24 hours of concrete placement, temperatures of concrete placed in the morning are higher than those placed in the afternoon, and the maximum concrete temperature occurred in the concrete placed at noon. Finally, from the 12 days of condition survey, it was noted that the rate of crack occurrence in the morning placed section was 25 percent greater than that in the afternoon placed section. Based on these findings, it is concluded that maximum concrete temperature has a significant effect on crack development, and boner concrete temperature control is needed to ensure adequate CRCP performance.

• Radiation Oncology Journal
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• v.16 no.2
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• pp.195-202
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• 1998

Purpose : In order to obtain basic data for treatment plan in radiosurgery, we measured small fields of 6 MV X-rays and compared the measured data with our Monte Carlo simulations for the small fields. Materials and Methods : The small fields of 1.0, 2.0 and 3.0 cm in diameter were used in this study. Percentage depth dose (PDD) and beam Profiles of those fields were measured and calculated. A small semiconductor detector, water phantoms, and a remote control system were used for the measurement Monte Carlo simulations were Performed using the EGS4 code with the input data prepared for the energy distribution of 6 MV X-rays, beam divergence, circular fields and the geometry of the water phantoms. Results : In the case of PDD values, the calculated values were lower than the measured values for all fields and depths, with the differences being 0.3 to 5.7% at the depths of 20 to 20.0 cm and 0.0 to 8.9% at the surface regions. As a result of the analysis of beam profiles for all field sizes at a depth of loom in water phantom, the measured 90% dose widths were in good agreement with the calculated values, however, the calculated Penumbra radii were 0.1 cm shorter than measured values. Conclusion : The measured PDDs and beam profiles agreement with the Monte Carlo calculations approximately. However, it is different when it comes to calculations in the area of phantom surface and penumbra because the Monte Carlo calculations were performed under the simplified geometries. Therefore, we have to study how to include the actual geometries and more precise data for the field area in Monte Carlo calculations. The Monte Carlo calculations will be used as a useful tool for the very complicated conditions in measurement and verification.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.73-77
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• 2012

Recently, Interest to the photoconductor, which is used to flat form X-ray detector such as a-Se, $HgI_2$, PbO, CdTe, $PbI_2$ etc. is increasing. In this study, the film layer by using the photoconductive material with particle sedimentation was fabricated and evaluated. The quantization efficiency of the continuous X-ray with the 70 kVp energy bandwidth was analyzed by using the Monte Carlo simulation. With the results, the thickness of film with 64 % quantization efficiency was 180 ${\mu}m$ which is similar to the efficiency of 500 ${\mu}m$ a-Se film. And $HIg_2$ film has the high quantization efficiency of 74 % on 240 ${\mu}m$ thickness. The electrical characteristics of the 239 ${\mu}m$ $Hgl_2$ films produced by particle sedimentation were shown as very low dark current(under 10 $pA/mm^2$), and high sensitivity(19.8 mC/mR-sec) with 1 $V/{\mu}m$ input voltage. The SNR, which is influence to the contrast of X-ray image, was shown highly as 3,125 in low driving voltage on 0.8 $V/{\mu}m$. With the results of this study, the development of the low-cost, high-performance image detector with film could be possible by replacing the film produced by particle sedimentation instead to a-Se detector.

• Economic and Environmental Geology
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• v.18 no.1
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• pp.65-92
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• 1985

A total of 12 mineral commodities significant in domestic output, economy and/or strategy of the Republic of Korea are chosen to examine the structural changes in production and demand-supply of these minerals during the last two decades of her industrialization. These include iron and manganese ores as the raw materials for iron and steel making, copper, zinc and tungsten ores among other non-ferrous metallic minerals, limestone (cement), kaolin, talc, pyrophyllite and graphite among other non-metallic minerals, and anthracite coal as the only domestic source of fossil energy. These are reviewed historically in time-series based on the statistical data which are tabulated and graphed in terms of domestic output, export, import, apparent demand-supply, its increasing rate, and self-sufficiency rate of each commodity. The increasing rates of demand-supply (IRDS) of some more important commodities are compared with those of Gross Domestic Production (GDP) and Economic Growth Rate (EGR) to evaluate how the IRDS contributed to the GDP and EGR. The major results revealed are as follows: Among the 12 commodities, the domestic output of 8 commodities appeared to have grown with steady upward trends: they are ores of lead, zinc and tungsten, limestone (cement), kaolin, talc, pyrophyllite and anthracite coal. Two commodities, ores of iron and copper, continued with unchanging or slightly declining trends and varied fluctuations, in spite of their cardinal importance to the heavy industry and strategy of Korea. The remaining two, graphite and manganese ore, have gradualy declined in domestic output in which the former has still enough resource potential but the latter has not and virtually ceased its domestic output. Trade patterns for mineral commodities in the Republic of Korea during the last two decades have changed greatly, being marked by a shift from mineral-exporting to mineral importing, mainly because of increasing consumption of mineral raw materials for industrialization rather than beceuse of decreasing output of domestic mineral commodities in quantity. In terms of trade patterns, the 12 commodities concerned in this study can be classified into the following four groups. The 1st group - ores of lead and tungsten have only been exported without imports. The 2nd group - amorphous graphite, and pyrophyllite have mainly been exported but partly been imported. The 3rd group - kaolin, talc and crystalline graphite have equally been exported and imported, but quantity of imports have rapidly been increased with time. The 4th group - ores of iron, manganese and zinc have shifted from exports to imports during the industrialization, particularly owing to the initiation of iron and steel making by the Pohang Iron and Steel Company in the middle 1970' s and the new establishment of the Onsan Zinc Refinery in the late 1970' s. All of the 12 commodities under considerations were far above 100% in self-sufficiency rate before or in the early 1960' s. Recently, however, most of them have been declined to below 100% except for those of limestone (cement) and pyrophyllite. It is particularly serious to identify that the self-sufficiency rates of the three important metallic minerals, iron, copper and manganese ores in 1982 appeared to be 5.1%, 0.5%, and 0.01%, respectively. The average self-sufficiency rate of the total domestic minerals produced in 1982 was 14.4% (in value) for that year. Mining industry appeared to be extremely high in its intermediate demand rate whereas its intermediate input rate to be quite low indicating that mineral raw materials have been exerted strong forward linkage effects upon the other industries rather than backward linkage effects. In comparing the curves of increasing rates of demand-supply of several major minerals - iron ore, manganese ore, copper ore, limestone (cement), kaolin, and anthracite coal - with those of Gross Domestic Production and Economic Growth Rate drawn on every graph, it is clearly shown that the curves of increasing rates of demand-supply comprise around 6 to 7 periods of cycles which roughly harmonious with those of the curves of GDP and EGR, except for the curve of anthracite coal of which the configuration seems to have resulted from the (artificial) government's mineral policy rather than from economic free market mechanism. The harmonic feature of these curves well suggests that the increasing rates of demand-supply of major minerals have been significantly contributed to the GDP and EGR. In addition, the wider amplitudes of the iron, manganese and copper curves than those of the limestone (cement) and kaolin curves indicate that the contribution of the former, metallic commodities, has been greater than that of the latter, non-metallic commodities.