• Journal of KIISE:Information Networking
• /
• v.37 no.5
• /
• pp.317-326
• /
• 2010

Nowadays, transmission bandwidth for network traffic is increasing and the type is varied such as peer-to-peer (PZP), real-time video, and so on, because distributed computing environment is spread and various network-based applications are developed. However, as PZP traffic occupies much volume among Internet backbone traffics, transmission bandwidth and quality of service(QoS) of other network applications such as web, ftp, and real-time video cannot be guaranteed. In previous research, the port-based technique which checks well-known port number and the Deep Packet Inspection(DPI) technique which checks the payload of packets were suggested for solving the problem of the P2P traffics, however there were difficulties to apply those methods to detection of P2P traffics because P2P applications are not used well-known port number and payload of packets may be encrypted. A proposed algorithm for identifying P2P heavy traffics based on flow transport parameters and behavioral characteristics can solve the problem of the port-based technique and the DPI technique. The focus of this paper is to identify P2P heavy traffic flows rather than all P2P traffics. P2P traffics are consist of two steps i)searching the opposite peer which have some contents ii) downloading the contents from one or more peers. We define P2P flow patterns on these P2P applications' features and then implement the system to classify P2P heavy traffics.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.9 no.2
• /
• pp.1296-1300
• /
• 1967

This study was made through the utilization of heavy soil taken from the experimental plot of heavy soil in Konkuk University, Changan-dong, Sungdong-ku, Seoul. The soil used in the experiment has the following physical characteristics: 1. The soil is very compact, impervious, and unfit for any plant growth, 2. For improvement of the soil, tile drainage practice has been employed, 3. According to the general theory of tile drainage, it is unnatural that the effect of drainage is actually observed in such a soil. The followings are the results of the experiment: 1. Water moved to crosswise when the plotted soil profile was not broke. In this case the upper sloped part was dry while the bottom part was moistned. The upper part of the tile was also moistned. 2. The crosswise movement of water was not observed in the artificially broken plot of subsoil. However, the water flow from the tile was observed for long period as a result of the increase of soil void, seepage, aeration, and water holding capacity. However, the water flow from the tile in the plot of unbroken subsoil was observed only in short period and soon the flow was stopped. 3. the distance between the tile laid in the heavy soil should not exceed 10m for the efficient drainage. 4. When the pF is 2.5 in the subsoil the moisture content was between 23.97% and 28.20%. However, when the water saturated in the subsoil the moisture content was between 34.30% and 22.10%. Accordingly without the higher pF than 2.5 the water can not be absorbed and therefore the drainage can not be occured.

• The Korean Journal of Ecology
• /
• v.6 no.2
• /
• pp.81-89
• /
• 1983

The change of environmental factors with flow rates were studied quantitatively for two rivers, the Nakdong River and the Sin stream, which have different basins in ecosystem structures, during short period after a heavy rain. In the Nakdong River, transparency, DO, alkalinity and hardness were negatively correlated with the flow rate by logarithmic function, but the concentration of SiO2 was relatively constant regardless of the flow chage. In the Sin stream, transparency, alkalinity, hardness and the concentration of NH3-N, NO2-N and SO4= showed negative correlation with the flow rate by logarithmic function. The ratios of maximum to minimum values for aquatic environmental factors during the samller than that for flow rate in the respective rivers (28 in the Nakdong R.; 50 in the Sin S.). Immediately after the heavy rain, the concentrations of NO2-N, NH3-N and PO4-P in the Sin stream were 8, 6 and 1 times as high as those in the Nakdong River, respectively, but in the stable flow state, those became 94, 25 and more than 10 times, respectively. The load for most of the dissolved environmental constituents changed similarly to the flow rate in both rivers. It is notable that, at the stable flow state, the loads for NH3-N (59g/sec) and NO2-N (3.3g/sec) in the Sin stream were 4.3 and 1.3 times as high as those in the Nakdong River.

• Journal of Environmental Science International
• /
• v.13 no.1
• /
• pp.61-68
• /
• 2004

Three kinds of toxic heavy metals, such as lead, copper, and cadmium, existing abundantly in contaminated soils were selected to investigate pH change, electroosmotic flow, and the removal rate in the application of electrokinetic process. In the change of pHs, they reached to about 12 and 2 at each cathodic and anodic region, respectively, and maintained for reaction being proceeded. Electroosmotic flow rates were not influenced by the kind of metal species but by electropotential gradient. On the soils contaminated by each metal, the removal rate of Cd was the fastest among three as in the order of Cd>Pb>Cu. While on the soils contaminated by mixed metal species, Cu was the fastest. Metal species transported by electrokinetic processes were distributed in between 0.9 and 1.0 of normalized region. In the case of soils contaminated by one kind of metal. the relative concentrations of Pb and Cd estimated in between normalized region 0.9 and 1.0 were 5.2 and 5.7, respectively.

• The Journal of Engineering Geology
• /
• v.20 no.1
• /
• pp.79-87
• /
• 2010

Field water qualities (temperature, pH, Eh, EC, DO) was monitored by 6 times March to September 2009 on background water (BW) and acid mine drainage (AMD0, AMD1, AMD2 and AMD3 points), and flow rate was measured on AMD0 point. Acid mine drainage flowed out from abandoned Ilgwang mine were high acid waters that lower than pH 3, and Eh component was ranged 400 to 600 mV. EC measured on acid mine drainage were higher over 10 times than background water, DO component was increased by reaction on the air during the water flow from AMD0 point to AMD4 point. Heavy metal concentrations in acid mine drainage were ordered Fe > Cu > Zn > Mn > As > Cd, and Fe concentration was highest for 81.870~474.30 mg/L. Monitoring periods measured maximum concentrations of heavy metals were May for As and Cd, June for Fe, July for Cu, Zn and Mn. The periods measured minimum concentrations were monitored April for Cd and Mn, September for Fe, Cu, Zn and As. Discharge mass of heavy metal components were calculated 53.44 kg for Fe, 6.25 kg for Cu, 5.26 kg for Zn, 2.13 kg for Mn, 0.14 kg for As and 0.04 kg for Cd, respectively. Total discharge mass of heavy metal components were calculated 67.26 kg for 1 day, and Fe component was taken 79% of total mass.

• Journal of Environmental Science International
• /
• v.13 no.2
• /
• pp.149-159
• /
• 2004

In the removal of heavy metals from the mine deposit using electrokinetic processes, the effects of operation under both constant current and constant potential conditions were estimated. The results of soil pH distributions for DDW-20 V and DDW-100 mA cases after the electrokinetic remediation tests were observed. In the former case, soil pH was not much changed and kept to almost constant value just little higher than initial soil pH of 3.52, except near the cathode, which was about pH 5. While in the latter case, soil pHs of anode and the cathode regions were less than pH 3 and about 6, respectively. The electroosmotic flow to the cathode increased rapidly till 10 hrs and decreased steadily and then maintained to constant rate until the end of operation at constant current condition. Electric potential gradient was continuously increased to as much as 34.375 V/cm. At the steady state, values of the apparent electric conductivity for DDW-20 V and DDW-100 mA were around 40 ${\mu}\textrm{s}$/cm and 30 ${\mu}\textrm{s}$/cm, respectively. In the DDW-100mA test, Cu, Cd, and Zn except Pb showed the tendency of moving toward the cathode. While in the DDW-20 V case, it was observed that Cu, Zn, and Pb except Cd were not moved to any directions. The results of the tests demonstrated that the electrokinetic soil remediation process could be operated better under constant current condition than constant electric potential condition.

• Journal of Soil and Groundwater Environment
• /
• v.8 no.1
• /
• pp.9-16
• /
• 2003

A new method has been proposed and developed that solves the problem of decreasing electroosmotic flow rate by excess $H^{+}$ and precipitation of heavy metal by $OH^{-}$. An electrolytic solution was circulated between the anode and cathode compartments that enabled the pH at the anode and cathode to be controlled. The change of the soil pH by circulation systems affects the operation time, by lowering the rate of increase of the electric potential gradient, and the removal efficiency of heavy metals, by affecting the soil pH. Since there was no effluent from the cathode compartment in circulation system, there was no need to treat the wastewater after the experiment, which resulted in the reduction of influent electrolyte volume.

• Journal of Drive and Control
• /
• v.11 no.2
• /
• pp.22-29
• /
• 2014

This paper presents simulation-based analysis of energy flow of a wheel loader. The objective of this study is to analyze the energy flow of a wheel loader during driving and working. Because the wheel loader powertrain consists of a mechanical and hydraulic powertrain, the generated power from the engine is divided into 2 powertrains. Further, a virtual prediction of energy flow in the powertrains is a key factor in terms of optimal design. Accordingly, the simulation model that is able to predict the virtual energy flow is developed and analyzed in this study. The proposed wheel loader simulation model has been constructed in the Matlab/Simulink environment. It is expected that the developed simulation model will analyze the energy flow and efficiency in the design stage.

• Journal of KIISE:Information Networking
• /
• v.34 no.4
• /
• pp.246-255
• /
• 2007

Due to the bandwidth-consuming characteristics of the heavy-hitter P2P applications, it has become critical to have the capability of pinpointing and mitigating P2P traffic. Traditional port-based classification scheme is no more adequate for this purpose because of newer P2P applications, which incorporating port-hopping techniques or disguising themselves as HTTP-based Internet disk services. Alternatively, packet filtering scheme based on payload signatures suggests more practical and accurate solution for this problem. Moreover, it can be easily deployed on existing IDSes. However, it is significantly difficult to maintain up-to-date signatures of P2P applications. Hence, the automatic signature generation method is essential and will be useful for successful signature-based traffic identification. In this paper, we suggest an automatic signature generation method for Internet disk P2P applications and provide an experimental results on CNU campus network.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.59-62
• /
• 1993

Spectrophotometric determination of some heavy lanthanide ions by flow injection method is described. Xylenol Orange forms water soluble chelates with lanthanide ions in a tris[hydroxymethyl]-aminomethane-buffered medium having pH 8.3 and containing cetyltrimethylammonium bromide. The molar absorptivities of Ln(III)-XO complexes were increased by the ternary system with cetyltrimethylammonium bromide with the concomitant bathochromic shift of absorption maxium compared to those of the binary system without cetyltrimethylammonium bromide. The calibration curves are linear in the range 0.25-1.00 ppm for Gd(III), Dy(III), Er(III), Tm(III) and Yb(III) and the dynamic range are very wide. The detection limits (S/N=2) are from 2 ppb for Gd(III) to 30 ppb for Yb(III) and the relative standard deviations are from 1.2% for 0.5 ppm Gd(III) to 1.8% for 0.5 ppm Yb(III). The sample throughput was ca. 50 $h^{-1}$.