• Journal of the Korea Society of Computer and Information
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• v.1 no.1
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• pp.147-158
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• 1996

This paper proposed a concurrency control structure based on specialized data flow graphs that was analysed a run-time concurrency control activity to be integrated with the task scheduler Data were viewed as flowing on the arcs from one node to another in a stream of discrete to tokens. The network that Is based upon the Entity-Relationship model, can be viewed a fixed problems used query tokens as a data flow graph. The performance was measured used in the various expriments compared the overall performance of the different concurrency control methods, DBFG (DataBase Flow graphs) scheduling had the knowledge to obtain better performance than 2PL in a distributed environment.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.323-330
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• 2005

Buffer overflow is one of the most prevalent and critical internet security vulnerabilities. Recently, various methods to prevent buffer overflow attacks have been investigated, but they are still difficult to apply to real applications due to their run-time overhead. This paper suggests an efficient rewrite method to prevent buffer-overflow attacks only with lower costs by generating a redundant copy of the return address in stack frame and comparing return address to copied return address. Not to be overwritten by the attack data the new copy will have the lower address number than local buffers have. In addition, for a safer execution environment, every vulnerable function call is transformed during the rewriting procedure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.277-280
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• 2004

The information on maritime affairs in South Korea has been provided by Ministry of Maritime Affairs and Fisheries, National fisheries Research and Development Institute, Korea Ocean Research and Development Institute, National Oceanographic Research Development Institute, and the information on marine products and maritime environment has been lively producing by laboratories, universities and other private-run institutes. In the developed countries, this information is not only open to the public to be used in a short time, but also is offered after processing it to be used conveniently. In South Korea, universities and laboratories produce, though it is very tiny volume, the data of information on maritime affairs.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.311-324
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• 2021

Investors have increasingly become interested in macroeconomic antecedents in order to better understand the investment environment and estimate the scope of profitable investment in equity markets. This study endeavors to examine the interdependency between the macroeconomic antecedents (international oil price (COP), Domestic gold price (GP), Rupee-dollar exchange rates (ER), Real interest rates (RIR), consumer price indices (CPI)), and the BSE Sensex and Nifty 50 index return. The data is converted into a natural logarithm for keeping it normal as well as for reducing the problem of heteroscedasticity. Monthly time series data from January 1992 to July 2019 is extracted from the Reserve Bank of India database with the application of financial Econometrics. Breusch-Godfrey serial correlation LM test for removal of autocorrelation, Breusch-Pagan-Godfrey test for removal of heteroscedasticity, Cointegration test and VECM test for testing cointegration between macroeconomic factors and market returns,] are employed to fit regression model. The Indian market returns are stable and positive but show intense volatility. When the series is stationary after the first difference, heteroskedasticity and serial correlation are not present. Different forecast accuracy measures point out macroeconomics can forecast future market returns of the Indian stock market. The step-by-step econometric tests show the long-run affiliation among macroeconomic antecedents.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.753-762
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• 2021

WebAssembly(WASM) is a low-level instruction format that can be run in a web environment. Since WASM has a excellent performance, various web applications use webassembly. However, according to our security analysis WASM has a security pitfall related to control flow integrity (CFI) for indirect calls. To address the problem in this paper we propose a new code instrumentation scheme to protect indirect calls, named WACFI. Specifically WACFI enhances a CFI technique for indirect call in WASM based on source code anlysis and binary instrumentation. To test the feasibility of WACFI, we applied WACFI to a sound-encoding application. According to our experimental results WACFI only adds 2.75% overhead on the execution time while protecting indirect calls safely.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.191-200
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• 2010

The "intelligent internet power outlets" realized in this study use Internet environment to connect electrical and electronic products to the Net as well as to enable remote monitoring and control. They also have temperature and light sensors, and even offer scheduling options by means of a universal calendar run by an inner real-time timer. Furthermore, they control 4 outlets handling 4 external input conditions and infrared remote control with easy-to-use functions for home automation control. The user interface is equipped with an embedded Web server and UDP protocol handler, and which also allows special control programs be used with the Web browser. Thus, installing this real-time power control function with optimal scheduling and various communication functions will provide you with energy-efficient power outlets outfitted with the increasingly popular "standby power" electric power efficiency.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.112-118
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• 2012

Fine suspended solids from mine drainage draw attentions due to their potential adverse influences on the water quality, such as increasing turbidity and degrading aesthetic landscape. Currently, sand filter beds are adapted in some mine drainage treating systems. However, more efficient system is in demand, as the existing sand beds reveal some problems, such as frequent maintenance intervals. Various filtering mediums including fly ash, mine tailing aggregates and the sand were tested for improving the current system, using column experimental set-up. Mine drainage samples were collected from the current treating systems in the abandoned H coal mine. The experiment was run for 7 days. Suspended solids recorded as 100.9 mg/L and the value exceeds the current standard, 30 mg/L. Sand was proved to still be the optimum medium for the fine suspended solids, compared to fly ash and fly ash + sand. Mine tailing aggregates were placed at the exit of the columns, substituting gravels. The tailing aggregates is made by mine tailings and clay. Sand bed filters can also be improved by mixing granular activated carbon, which was found to be economical and efficient in the batch experiment, conducted at the same time.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.119-126
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• 2002

Recently, the flux community in Korea established a new regional flux network, so-called KoFlux, which will provide an infrastructure for collecting, synthesizing, and analysing long-term measurements of energy and mass exchange between the atmosphere and the various vegetated surfaces. KoFlux requires the collection of long time series of raw data, and a large amount of data are expected to accumulate due to continuous flux observations at each KoFlux sites. Therefore, we need a systematic and efficient tool to manage these raw data. As a part of this effort, a computer program far processing raw data measured from micrometeorological field experiments was developed for the flux community in Korea. In this paper, we introduce this program for processing raw data to estimate fluxes and other turbulent statistics and explain the micrometeolological processes coded in this data-processing program. Also, we show some examples on how to run the program and handle the outputs for the unique purpose of research interest.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.293-304
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• 2006

Sea water samples collected in August, 1994 from 20 stations in the Kwangyang Bay were analyzed by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) to investigate persistence and distribution pattern of four organophosphorus pesticides (DDVP, Diazinon, IBP, EDDP). Except for IBP, the contamination by DDVP, Diazinon, and EDDP in marine aquatic environment in Korea has not been reported previously. In this study, however, all these four pesticides were detected in all stations (except DDVP) and their concentrations were in ng/L level. The concentrations ranged from detection limit to 15.3ng/L for DDVP, 1.8-27.7ng/L for Diazinon, 7.3-63.5ng/L for IBP, and 22.2-1100.1ng/L for EDDP. It is noteworthy that the measured concentrations of IBP and EDDP in this study would be much lower than usual, since the use of IBP and EDDP was less than 50% of average annual consumption due to unusually dry and hot weather condition in the summer of 1994. It was very surprising to find that the highest concentrations of organophosphorus pesticides were observed at stations near Daesa Streamlet instead of Seomjin River, which has more point source of the pesticides. This result suggests that the small river discharge during heavy ram period in summer can give harmful effect on marine biota (both wild and aqua-cultured) with its organophosphorus pesticide residue, despite of their short residence time in aquatic environment. In order to protect the marine life properly from acute toxicity of the organophosphorus pesticides, it needs to be emphasized that monitoring the level of agricultural pesticides in river run-off should be done during active consumption period rather at regular intervals.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.843-850
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• 2012

Due to the fast response to algae bloom issue in drinking water treatment plant, very fast determination methodology for algal toxin is required. In this study, column switching technique based online preconcentration method was combined with high resolution full scan mass spectrometer to save sample preparation time and to obtain fast and accurate result. After parameter optimization of online preconcentration, 1mL filtered sample was directly injected to trap column with switching valve system. Next, target toxins are eluted by 98% acetonitrile and analysed with 150 - 1,100 amu scan range at 50,000 resolving power. Method detection limit (MDL) for microcystin-LR, the most toxic isomer, was 0.1 ng/mL and others such as microcystin-YR, microcystin-RR and nodularin were 0.08, 0.03 and 0.04 ng/mL, respectively. This is the best improved sensitivities with 1mL volume in the literature. Furthermore, due to the use of ultra pressure HPLC (UPLC), the whole method run was completed in 4 min. Real sample applications for 173 sample including 55 surface water and 118 treatment plant samples for raw and treated water could be done within 16 hours. In our calculation, this methodology is roughly 80% faster than the previous manual solid-phase extraction with LC-MS/MS method.