• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.8
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• pp.1161-1170
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• 2013

Currently in 2013, a law that was drawn as a result of social agreement for personal information protection was enacted, and through several amendments, definite policy of written law and guideline were presented for definitive information protection in various fields of social business including IT field. Based on a series of social issues about the importance of personal information, a new access paradigm to personal information appeared. And from macroscopic access method called information protection, the necessity of technical access method came to the fore. Of course, it seems somewhat irrational to restrict all data in the form of personal information to a certain category of information until now. But in the deluge of information based on IT field, it is true that the part of checking the flow of personal information and selecting as security target has been standardized. But still there are cases in which it is difficult to routinely apply the five standardized flows of personal information Life-Cycle-collect, process, provide, store, and destroy-to information that all companies and organizations have. Therefore, the researcher proposes the standardized methodology by proposing the access control methodology for dualised hierarchical personal information Life-Cycle. The results of this research aim to provide practical data which makes optimal access control to personal information Life-Cycle possible.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.179-189
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• 2008

The performance of Lean NOx Trap (LNT) based on the catalysts of Pt/K/Ba/$\gamma-Al_2O_3$ with proprietary washcoat formulation is studied using a bench flow reactor system. To investigate the effect of temperature and gas hourly space velocity (GHSV) on the nitrogen oxides (NOx) trapping capacity as well as NOx breakthrough time and final ratio of $NO_2$ to NO of LNT, series of adsorption isotherms are carried out with simulated exhaust gases of the lean burn engines. Since typical operation of LNT requires periodic regeneration with a short rich excursion, where the stored or trapped NOx is released and subsequently reduced to $N_2$, the effect of the duration of lean and rich phase and type of reductants on the NOx conversion is investigated. NOx storage capacity and breakthrough time obtained from adsorption isotherms shows a volcano-type dependence on the temperature with a maximum NOx storage capacity occurring $350^{\circ}C$ and with a maximum breakthrough time occurring $400^{\circ}C$ at all GHSVs investigated in this study. Also, maximum ratio of $NO_2$ to NO is obtained at $400^{\circ}C$ with a GHSV of $75,000\;hr^{-1}$ Lean/rich cycle of 100 s lean and 5 s rich used with a concentration of 1.33% of $H_2$ and 4% of CO in the rich phase is found to be optimum at operating temperature of $350^{\circ}C$ and a GHSV of $50,000\;hr^{-1}$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.3
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• pp.179-192
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• 2013

This study is characterized the groundwater flow pattern near crystalline site of Yangbook-Myeon, Gyeong-ju City, South Korea. From the time series analyses, groundwater level could be classified into 4 types reflecting the hydrogeological characteristics and rainfall pattern. The type I (DB1-1, DB1-2) may be directly influenced by rainfall pattern. The type II (DB1-3, DB1-7, KB-1, KB-2, KB-3, KB-7, KB-14, KB-15) may be influenced by rainfall event as well as groundwater flow through water-conducting features. The type III (DB-5, DB1-6, DB2-2, KB-10, KB-11, KB-13) may be predominantly happens in the crystaline rock mass, groundwater in this type flows through the minor fracture networks rather than direct effect of rainfall event. The type IV (DB1-8, KB-9) may be influenced by irregular variation of the groundwater level due to anisotropy and heterogeneity of crystalline rock.

• Journal of Korea Water Resources Association
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• v.37 no.4
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• pp.305-314
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• 2004

Climate change mainly due to the increase of green house gases cause different patterns of water cycle within the basin. However, it is common that current planning and management practices do not consider the effect of the climate change. So, this study evaluated the effect of climate change on the water circulation within the watershed. This study used several GCM simulations for the double $CO_2$condition for the generation of temperature and rainfall series using the Markov chain. Daily runoff series for 100 years were generated using a rainfall-runoff model. As results. annual temperature increase by ＋3.2 ∼＋4.6$^{\circ}C$, annual precipitation change －7 ∼ ＋8 %, annual runoff change －14 ∼ ＋7 %, and potential evapotranspiration amount change ＋3 ∼＋4 % for the change of 1 $^{\circ}C$ are found to be expected depending on GCM simulations. Even though the simulation results are very dependent on the GCM predictions considered, overall variability of runoff is expected to become higher than the current state.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.233-239
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• 2011

A series of computational analyses was performed to predict the cooling process by the cooling channel of preburners used for kerosene-liquid oxygen staged combustion cycle rocket engines. As an oxygen-rich combustion occurs in the kerosene fueled preburner, it is of great importance to control the wall temperature so that it does not exceed the critical temperature. However, since the heat transfer is proportional to the speed of fluid running inside the channel, the high heat transfer leads to a trade-off of pressure loss. For this reason, it is necessary to establish a certain criteria between the pressure loss and the heat transfer or the wall surface temperature. The design factors of the cooling channel were determined by the computational research, and a test model was manufactured. The test model was used for the hot fire tests to prove the function of the cooling mechanism, among other purposes.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.67-74
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• 2019

Apparent changes in the natural hydrologic cycle causing more frequent floods in urban areas and surface water quality impairment have led stormwater management solutions towards the use of green and sustainable practices that aims to replicate pre-urbanization hydrology. Among the widely documented applications are infiltration techniques that temporarily store rainfall runoff while promoting evapotranspiration, groundwater recharge through infiltration, and diffuse pollutant reduction. In this study, a laboratory-scale infiltration device was built to be able to observe and determine the factors affecting flow variations and corresponding solids removal through a series of experiments employing semi-synthetic stormwater runoff. Results reveal that runoff and solids reduction is greatly influenced by the infiltration capability of the underlying soil which is also affected by rainfall intensity and the available depth for water storage. For gravel-filled structures, a depth of at least 1 m and subsoil infiltration rates of not more than 200 mm/h are suggested for optimum volume reduction and pollutant removal. Moreover, it was found that the length of the structure is more critical than the depth for applications in low infiltration soils. These findings provide a contribution to existing guidelines and current understanding in design and applicability of infiltration systems.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.3930-3943
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• 2021

To improve the capability of the SAS4A code, which simulates the initiating phase of core disruptive accidents for MOX-fueled Sodium-cooled Fast Reactors (SFRs), the authors have investigated in detail the physical phenomena under unprotected loss-of-flow (ULOF) conditions in a previous paper (Kawada and Suzuki, 2020) [1]. As the conclusion of the last article, fuel stub motion, in which the residual fuel pellets would move toward the core central region after fuel pin disruption, was identified as one of the key phenomena to be appropriately simulated for the initiating phase of ULOF. In the present paper, based on the analysis of the experimental data, the behaviors related to the stub motion were evaluated and quantified by the author from scratch. A simple model describing fuel stub motion, which was not modeled in the previous SAS4A code, was newly proposed. The applicability of the proposed model was validated through a series of analyses for the CABRI experiments, by which the stub motion would be represented with reasonable conservativeness for the reactivity evaluation of disrupted core.

• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.50-54
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• 2016

The performance of a scroll expander is the most important factor for the efficiency of small scale Organic Rankine cycle waste heat power generation systems. In this research, a scroll compressor was purchased and operated in reverse to function as a scroll expander. With air as a working fluid, a series of performance test were conducted on this expander by varying the inlet and outlet pressure. Secondly, We have tested through 2000 to 3500 rpm rotational speed to find the maximum power and efficiency of the expander. And last, It was observed in the initial experiments that the design of the expander's orbiting scroll wrap partially blocked the fluid intake which may have caused unnecessary flow resistance. To verify this theory, a small part of the scroll wrap was removed and the performance test was redone. It was observed that the lower back pressure assure the higher efficiency and power of expander and the rotational speed that shows maximum adiabetic efficiency of scroll expander is 69% at 2500 rpm. And by modified wrap of the scroll, we could get volume flow rate for 13% to 19% and power for 5% to 18% increased. But the maximum efficiency of the modified scroll was decreased 8%.

• Korean Journal of Remote Sensing
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• v.29 no.5
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• pp.443-459
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• 2013

Located on Java subduction zone, Merapi volcano is an active stratovolcano with a volcanic activity cycle of 1-5 years. Merapi's eruptions were relatively small with VEI 1-3. However, the most recent eruption occurred in 2010 was quite violent with VEI 4 and 386 people were killed. In this study, we have attempted to study the characteristics of Merapi's eruptions during 18 years using optical Landsat images. We have collected a total of 55 Landsat images acquired from July 6, 1994 to September 1, 2012 to identify pyroclastic flows and their temporal changes from false color images. To extract areal extents of pyroclastic flows, we have performed supervised classification after atmospheric correction by using COST model. As a result, the extracted dimensions of pyroclastic flows are nearly identical to the CVP monthly reports. We have converted the thermal band of Landsat TM and ETM+ to the surface temperature using NASA empirical formula and calculated time-series of the mean surface temperature in the area of peak temperature surrounding the crater. The mean surface temperature around the crater repeatedly showed the tendency to rapidly rise before eruptions and cool down after eruptions. Although Landsat satellite images had some limitations due to weather conditions, these images were useful tool to observe the precursor changes in surface temperature before eruptions and map the pyroclastic flow deposits after eruptions at Merapi volcano.

• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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• pp.65-74
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• 2006

Modem drug discovery requires rapid pharmacokinetic evaluation of chemically diverse compounds for early candidate selection. This demands the development of analytical methods that offer high-throughput of samples. Naturally, liquid chromatography / tandem mass spectrometry (LC-MS/MS) is choice of the analytical method because of its superior sensitivity and selectivity. As a result of the short analysis time(typically 3-5min) by LC-MS/MS, sample preparation has become the rate- determining step in the whole analytical cycle. Consequently tremendous efforts are being made to speed up and automate this step. In a typical automated 96-well SPE(solid-phase extraction) procedure, plasma samples are transferred to the 96-well SPE plate, internal standard and aqueous buffer solutions are added and then vacuum is applied using the robotic liquid handling system. It takes only 20-90 min to process 96 samples by automated SPE and the analyst is physically occupied for only approximately 10 min. Recently, the ultra-high flow rate liquid chromatography (turbulent-flow chromatography)has sparked a huge interest for rapid and direct quantitation of drugs in plasma. There is no sample preparation except for sample aliquotting, internal standard addition and centrifugation. This type of analysis is achieved by using a small diameter column with a large particle size(30-5O ${\mu}$m) and a high flow rate, typically between 3-5 ml/min. Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of pcrous silica. The main advantage of such a network is decreased backpressure due to macropores (2 ${\mu}$m) throughout the network. This allows high flow rates, and hence fast analyses that are unattainable with traditional particulate columns. The reduction of particle diameter in HPLC results in increased column efficiency. use of small particles (<2 urn), however, requires p.essu.es beyond the traditional 6,000 psi of conventional pumping devices. Instrumental development in recent years has resulted in pumping devices capable of handling the requirements of columns packed with small particles. The staggered parallel HPLC system consists of four fully independent binary HPLC pumps, a modified auto sampler, and a series of switching and selector valves all controlled by a single computer program. The system improves sample throughput without sacrificing chromatographic separation or data quality. Sample throughput can be increased nearly four-fold without requiring significant changes in current analytical procedures. The process of Bioanalytical Method Validation is required by the FDA to assess and verify the performance of a chronlatographic method prior to its application in sample analysis. The validation should address the selectivity, linearity, accuracy, precision and stability of the method. This presentation will provide all overview of the work required to accomplish a full validation and show how a chromatographic method is suitable for toxirokinetic sample analysis. A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method developed to quantitate drug levels in dog plasma will be used as an example of tile process.