• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.8
• /
• pp.2214-2229
• /
• 2024

Wireless sensor network (WSN) consists of large number of sensor nodes that are deployed in geographical locations to collect sensed information, process data and communicate it to the control station for further processing. Due the unfriendly environment where the sensors are deployed, there exist many possibilities of malicious nodes which performs malicious activities in the network. Therefore, the security threats affect performance and life time of sensor networks, whereas various security aspects are there to address security issues in WSN namely Cryptography, Trust Management, Intrusion Detection System (IDS) and Intrusion Prevention Systems (IPS). However, IDS detect the malicious activities and produce an alarm. These malicious activities exploit vulnerabilities in the network layer and affect all layers in the network. Existing feature selection methods such as filter-based methods are not considering the redundancy of the selected features and wrapper method has high risk of overfitting the classification of intrusion. Due to overfitting, the classification algorithm fails to detect the intrusion in better manner. The main objective of this paper is to provide the efficient feature selection algorithm which was suitable for any type classification algorithm to detect the intrusion in an effective manner. This paper, the security of the network is addressed by proposing Feature Selection Algorithm using Chi Squared with Ensemble Method (FSChE). The proposed scheme employs the combination of decision tree along with the random forest classification algorithm to form ensemble classifier. The experimental results justify the feasibility of the proposed scheme in terms of attack detection, packet delivery ratio and time analysis by employing NSL KDD cup data Set. The obtained results shows that the proposed ensemble method increases the overall performance by 10% to 25% with respect to mentioned parameters.

• Korean Journal of Breeding Science
• /
• v.43 no.5
• /
• pp.448-456
• /
• 2011

We used suppression subtractive hybridization (SSH) combined with mirror orientation selection (MOS) method to screen differentially expressed genes from red-fleshed kiwifruit 'Hongyang'. As a result, the 288 clones were obtained by subcloning PCR product and 192 clones that showed positive clones on colony PCR analysis were selected. All the positive clones were sequenced. After comparisons with the NCBI/Genbank database using the BLAST search revealed that 30 clones showed sequence similarity to genes from other organisms; 10 clones showed significant sequence similarity to known genes. Among these clones, 3 clones (AcF21, AcF42 and AcF106) had sequence homology to 1-aminicyclopropane-carboxylic acid (ACC)-oxidase (ACO) that known to be related to fruit ripening. The expression patterns of differentially expressed genes were further investigated to validate the SSH data by reverse transcription PCR (RT-PCR) and quantitative real-time PCR (qReal-time PCR) analysis. All the data from qReal-time PCR analysis coincide with the results obtained from RT-PCR analysis. Three clones were expressed at higher levels in 'Hongyang' than 'Hayward'. AcF21 was highly expressed in the other genes at 120 days after full bloom (DAFB) and 160 DAFB of 'Hongyang'.

• Korean journal of applied entomology
• /
• v.39 no.3
• /
• pp.157-163
• /
• 2000

In a previous report, 50 potato cultivars were screened for infestation levels by the coppery click beetle (Selatosomus puncticollis Motschulsky) in the field. Subsequently, we selected 10 potato cultivars (Anco, Atlantic, Bintje, Dejima, Denali, Jopung, Irish Cobbler, Namsuh, Shepody, and Superior) to evaluate feeding preferences by wireworms, and to analyze some factors associated with resistance. The injury rates and number of holes in potato tubers damaged by larvae of S. puncticollis were checked in the field and laboratory. Additionally, some of their chemical characters (contents of glycoalkaloids, total-nitrogen, Ca, K, Mg, sugars, and starch) were quantified. And finally correlation analysis was conducted to see whether there is a possible relationship between these characteristics and the damage level. The tuber injury rates by S. puncticollis larvae were generally high showing 19% to 73% of damage level. The highest number of tuber hole damaged by S. puncticollis larvae was found on cv. Namsuh, but generally fewer on cvs. Anco, Atlantic, Bintje, Denali and Superior. No activities for $\alpha$-chaconine, $\alpha$-solanine and $\alpha$-tomatine at a concentration of 2,500 ppm were found to S. puncticollis larvae. The contents of glycoalkaloids in tuber were different depending on cultivars. In tubers, cv. Superior contained the highest level of 18.8 mg%, but cv. Irish Cobbler had the lowest level of 6.39 mg%. Concentrations of reducing sugars and total free sugars in tubers of cv. Namsuh were 0.71 % and 2.95%, but 0.26% and 1.77% in those of cv. Dejima, respectively. For the content of potato starch, cvs. Bintje, Dejima and Irish Cobbler showed higher level, but cvs. Jopung and Shepody lower. The highest contents of total nitrogen, Ca, K and Mg in tuber were found on cvs. Anco, Atlantic, Anco and Jopung, respectively. From correlation analyses, injury rate by S. puncticollis larvae was correlated with total nitrogen content (r = -0.71435*) and total sugar content in tuber (r = 0.78018*). Such information will become essential in developing integrated pest management programs and also in breeding new potato cultivars resistant to the wireworms.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.6B
• /
• pp.731-741
• /
• 2008

Previous studies on the numerical simulation at the tidal reach of Han River tend to restrict downstream boundary as Jeon-ryu station due to difficulties in gaining cross section data and tidal elevation values at Yu-do. But, in this study, geometries beyond the confluence of Gok-reung stream and Im-jin River are constructed based on the numerical sea map; tidal elevation at the downstream boundary, Yu-do is estimated by harmonic analysis of In-cheon tide gage station so that hydrodynamic and diffusion behavior have been analyzed. The domain ranging from Shin-gok submerged weir to Yu-do is selected (which is 36.8 km in length). RMA-2 and RAM4 developed by Il Won Seo (2008) are applied to simulate flow and diffusion behavior, respectively. Numerical results of flow characteristic are compared with the measured data at Jeon-ryu station. Simulation is carried out from June 23 to 25 in 2006 on the ground that hydrologic data is satisfactory and tidal difference is huge during that period. The result shows that reverse flow occurs 5 times according to the tidal elevation at Yu-do and the maximum reverse flow is observed up to Jang-hang IC, which is 32.9 km in length. Also analysis is focused on the process of generation and disappearance of reverse flow, the distribution of water surface elevation and velocity along the maximum velocity line, and the transport of nonconservative pollutant. Pollutant injected from Gul-po stream spreads widely across the river; however, the size of BOD cloud entering from Gok-reung stream is relatively small because water depth at the mid and left side becomes deeper and maximum velocity occurs along the right bank so that transverse mixing is completed quickly. Finally, mixing characteristic of horizontal salinity distribution is obtained by estimating the salinity input with analytical solution of 1D advection-dispersion equation.

• Research in Plant Disease
• /
• v.16 no.1
• /
• pp.41-47
• /
• 2010

A total of 10,753 oligotrophic bacteria were isolated from the cultivated soils of red-pepper infected by Phytophthora blight disease in various regions of Korea (Chungju, Anmyon, Taean, Andong, Eumsung and Goesan). Seven bacteria isolates among these collected resources were selected by the first screening of in vitro antagonistic assay against major several plant pathogenic fungi including Phytophthora capsici. Finally, strain 7F was selected by pot assay for a possible biological control agent against Phytophthora blight disease of pepper seedling in the greenhouse. Strain 7F was identified as Bacillus subtilis on the basis of its 16S rDNA sequence analysis and as standardized biochemical characteristics assay kits such as API20 NE. In the experiment of P. capsici zoospore infected red-pepper on the pot test, infection rate of red-pepper with nonetreatment to Phytophthora blight disease was 87%, while the rate was only 6% in the pot treated with strain 7F. This result indicated that the Bacillus subtilis strain 7F will be useful as a potential biocontrol agent for Phytophthora blight disease of red-pepper.

• Journal of forensic and investigative science
• /
• v.2 no.1
• /
• pp.23-31
• /
• 2007

Apartments are built in small countries to accommodate densely populated cities and maximize urbanization. Many apartment complexes have been built in recent reconstruction or redevelopment projects. An increase in crime has resulted due to residents living in a narrow space. Larceny is the most commonly reported crime in apartment complexes. Apartments can be classified as stairway, hallway, or plane surface. This study compares and analyzes the frequency of theft by apartment type to assist in creating a safer residential space. In America and England, scholars studied to make a safer residential space, and have applied the theory of 'the Defensible Space' and 'Crime Prevention Through Environmental Design(CPTED)' since 1970s. Korean apartment design now reflects CPTED in new apartment construction. In this study, 12 apartment complexes were selected in Changwon city to conduct analysis of theft in selected complexes. The study will cover housing invasion theft, motorcycle and car theft and snatching. The most frequency larceny is motorcycle and car theft, the second is housing invasion theft, and the least frequent is snatching. More residents' motorcycles and cars are damaged in a hallway style apartment. More frequently inhabitants have their possessions snatched on a stairway form. 1) When we build new apartment complexes, we must plan to improve territoriality and enhance a natural surveillance by reinforcing dwellers' relationship. Through planning we can prevention the larceny in apartments.

• Korean Journal of Occupational Health Nursing
• /
• v.10 no.2
• /
• pp.174-182
• /
• 2001

This study was performed to find out the differences between noise levels of hospital wards and the nurses efforts for noise management in some general hospitals. The hospital wards selected were the intensive care unit(ICU), the emergency room(ER), the nursery room(NR), the internal medicine(IM), the general surgery(GS) among the 5 general hospitals located in Seoul. The data were collected from August 3 to September 13, 1999 through questionnaire survey and noise measurement in each nursing station of hospital wards. Data analysis was done by SPSS 8.0 package among the 305 questionnaires and 24 hours monitored noise levels. Frequency, Chi-square and ANOVA test were used. The study results were as belows: 1. The noise level measured by 24 hours monitoring survey were exceeded on the standard limit in all the hospital wards. Data also showed that noise levels were significantly different in each ward among the three shifts working duties. 2. The subjects were all female nurses. They were mostly working in the ICU ward(28.9%). They were 26~30 years old (43.9%), junior college graduates(57.0%), working for 1~5 years(55.1%) as staff-nurse(85.6%). There were no significant differences between hospital wards and general characteristics of nurses. 3. The noise levels perceived by nurses were regarded as 'Highly noisy'(56.4%), especially during the 11:30 and 15:30 (30.2%) o'clock. Data also showed that noise education was not ever given to nurses(89.9%). Nurses also responded that they hardly put an effort to reduce noise level(54.8%). However, there were significant differences between wards and noisy working time, experience of noise education and level of effort for noise reduction. 4. Nurses also perceived the ventilator alarm and EKG-alarm as the most disturbing sounds in the ICU, human voice and telephone ringing in the ER, human voice and EKG-alarming in the NR, human voices and telephone ringing in IM and GS both wards respectively in order. There were significant differences between hospital wards and noise making factors. 5. Nurses were shown that they regarded highly 'Sound reduction of the human voice', 'Careful handling on medical instruments', and 'Immediate appliances on alarming materials' as the practical method for noise management. There were significant differences between hospital wards and behavioral practical efforts for noise management. According to that results, the statistical differences were shown in the 24 hour monitored noise levels in each ward. Also, nurses perceived the noise severity differently and they approached variously on the practical efforts for noise reduction in each ward. Thus, author thinks that concrete and systematic endeavor will be necessary for noise reduction and management in hospitals for better working and healing environment for both of patients and staffs.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.2
• /
• pp.227-235
• /
• 2018

In this study, we developed a relational formula for observing high - resolution rainfall using vehicle rain sensor. The vehicle rain sensor consists of eight channels. Each channel generates a sensor signal by detecting the amount of rainfall on the windshield of the vehicle when rainfall occurs. The higher the rainfall, the lower the sensor signal is. Using these characteristics of the sensor signal generated by the rain sensor, we developed a relational expression. In order to generate specific rainfall, an artificial rainfall generator was constructed and the change of the sensor signal according to the variation of the rainfall amount in the artificial rainfall generator was analyzed. Among them, the optimal sensor channel which reflects various rainfall amounts through the sensitivity analysis was selected. The sensor signal was generated in 5 minutes using the selected channel and the representative values of the generated 5 - minute sensor signals were set as the average, 25th, 50th, and 75th quartiles. The calculated rainfall values were applied to the actual rainfall data using the constructed relational equation and the calculated rainfall amount was compared with the rainfall values observed at the rainfall station. Although the reliability of the relational expression was somewhat lower than that of the data of the verification result data, it was judged that the experimental data of the residual range was insufficient. The rainfall value was calculated by applying the developed relation to the actual rainfall, and compared with the rainfall value generated by the ground rainfall observation instrument observed at the same time to verify the reliability. As a result, the rain sensor showed a fine rainfall of less than 0.5 mm And the average observation error was 0.36mm.

• Atmosphere
• /
• v.16 no.1
• /
• pp.19-31
• /
• 2006

The purpose of this study is to develop the statistical model to predict sea level pressure of typhoon period in south coast of the Korean Peninsula. Seven typhoons, which struck south coast of the Korean Peninsula, are selected for this study, and the data for analysis include the central pressure and location of typhoon, and sea level pressure and location of 19 observing site. Models employed in this study are the first order regression, the second order regression and the neural network. The dependent variable of each model is a 3-hr interval sea level pressure at each station. The cause variables are the central pressure of typhoon, distance between typhoon center and observing site, and sea level pressure of 3 hrs before, whereas the indicative variable reveals whether it is before or after typhoon passing. The data are classified into two groups - one is the full data obtained during typhoon period and the other is the data that sea level pressure is less than 1000 hPa. The stepwise selection method is used in the regression model while the node number is selected in the neural network by the Schwarz's Bayesian Criterion. The performance of each model is compared in terms of the root-mean square error. It turns out that the neural network shows better performance than other models, and the case using the full data produces similar or better results than the case using the other data.

• Korean Journal of Remote Sensing
• /
• v.24 no.4
• /
• pp.351-358
• /
• 2008

KOMPSAT-5 will be launched in 2010 carrying a SAR (Synthetic Aperture Radar) system to obtain high resolution images of the earth surface regardless of weather or solar condition. In this paper, the orbits of KOMPSAT-5 and the imaging modes of SAR were analyzed for radargrammetry, and the best image pairs were suggested. We set the pass number from the nearest orbit to a given ground point and selected image pairs for radargrarnmetry, with height sensitivity of parallax higher than 0.5 to achieve enough height resolution and with the value lower than 0.8 to avoid errors from geometric distortion. On the equator, for example, where the distance between two adjacent passes is fixed to 95 km, we solved the orbit geometry and found that the image pairs with the pass numbers of 3-2 and 5-3 are suitable for radargrarnmetry. As the examples with arbitrary latitude, we selected Daejeon and Sejong Antarctic stations and calculated the orbital elements by using STK software. Three image pairs (5-4, 7-5 and 8-5) were found suitable for radargrammetry at Daejeon while 10 pairs (8-6, 9-7, 10-7, 11-8, 12-8, 13-9, 14-9, 15-9, 15-10 and 15-11) at Sejong Antarctic station.