• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.14-26
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• 2008

IP over Ethernet technology widely used as Internet access uses the ARP(Address Resolution Protocol) that translates an ip address to the corresponding MAC address. recently, there are ARP security attacks that intentionally modify the IP address and its corresponding MAC address, utilizing various tools like "snoopspy". Since ARP attacks can redirect packets to different MAC address other than destination, attackers can eavesdrop packets, change their contents, or hijack the connection. Because the ARP attack is performed at data link layer, it can not be protected by security mechanisms such as Secure Shell(SSH) or Secure Sockets Layer(SSL). Thus, in this paper, we classify the ARP attack into downstream ARP spoofing attack and upstream ARP redirection attack, and propose a new security mechanism using DHCP information for acquisition of IP address. We propose a "DHCP snoop mechanism" or "DHCP sniffing/inspection mechanism" for ARP spoofing attack, and a "static binding mechanism" for ARP redirection attack. The proposed security mechanisms for ARP attacks can be widely used to reinforce the security of the next generation internet access networks including BcN.

• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.212-224
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• 1998

There are two major factors of degrading the performance in the forward link of DS/CDMA systems. One is the multiple access interference (MAI) caused by using the same frequency bands simultaneously and the other is the multipath lading due to multipath propagation. PN codes which have minimum cross correlation properties among spread spectrum codes are necessary to reduce the MAI. In the conventional IS-95A system, the PN sequence has the period of $2^{15}$ and is of the length of 64 chips for spreading each data. In this case, since the length of PN code per bit is very short compared to the period of the PN code, the performance of the conventional system is not satisfied in view of suppressing the multipath interference. However, the correlation property of the PN codes at the demodulation can be improved by increasing the interval of Integration at the demodulation. This paper proposes a demodulation method to reduce the cross correlation among PN codes. The performance of the proposed demodulation method is investigated through computer simulations. We used multipath Ray lading channel and AWGN channel in the simulation. Our simulation results show the improved performance of $0.25{\sim}0.5dB$ SNR in a given BER compared to the conventional demodulation scheme.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.34-41
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• 2011

At present wireless internet access service is available through the 3G network, mobile WiMAX and WiFi anytime and anywhere. In this environment where there are various networks, users should be able to select specific networks depending on different situations. And it is necessary to provide mobility support between homogeneous and between heterogenous networks. Given this situation, the many proposals have been presented to link 3G, which has the largest service area among various networks, with mobile WiMAX(IEEE 802.16e), or with WiFi(IEEE 802.11). But, recently, with the increasing volume of wireless internet use and wireless internet data, due to the advents of net-book, e-book and smart phone, the service area of WiFi and mobile WiMAX has rapidly expanded. Especially, the availability of real-time application such as internet phone has led to the relative shrinking of the proportion of 3G mobile communication network giving conventional voice service, and enlargement of those of wireless internet access networks like WiFi and mobile WiMAX. This paper suggests a handover scheme based on PMIPv6, whitch support mobility between WiFi and mobile WiMAX, and minimizes handover delay. In this scheme, the mobile node has a dual stack structure composed of two interfaces-WiFi and mobile WiMAX. Since WiFi dose not support mobility, it is suggested that the mobile node have the capacity to deal with handover signaling between gateway in case of handover between homogeneous networks. This handover scheme, suggested comparing with current handovers between homogeneous networks, has proved, in its analytic evaluation, to be able to reduce handover, transmission, and signaling overhead.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6101-6104
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• 2012

Background: Breast cancer accounts about one million from total annual ten million new diagnosed cases of neoplasia worldwide and is the main cause of death due to cancer in women. Tamoxifen is the most popular selective estrogen receptor modulator used in anti estrogen treatments. Tamoxifen must be converted into its metabolite endoxifen for biologic effects; this conversion process is catalysed by highly polymorphic cytochrome P450 2D6 (CYP2D6). This study surveyed copy number variation of the CYP2D6 gene and its possible correlation with Tamoxifen resistance in breast cancer patients. Methods: This case control study was performed on samples taken from 79 patients with breast cancer who used tamoxifen in Yazd and Tehran Cities, Iran. Real time reactions were conducted for 10 healthy samples using the comparative $C_t$ (Cycles threshold) method, each pair of genes being compared and samples with ratios around 1 were taken as control samples. Proliferation reactions were done by Real-Time PCR ABI Prism 7500. All registered data were transformed into SPSS 15 program and analyzed. Results: Efficiency of PCR for both CYP2D6 and ALB genes was 100%. From all 23 drug resistant patients 21.7% had one copy, 47.8% two copies and 30.4% had three copies. Also from all 56 drug sensitive patients, 26.8% had one copy, 51.8% two copies and 21.4% had three copies. The percentage of patients with one and two copies was similar between two groups but patients with three copies were more likely to belong to the drug resistant group more. Odd ratios for one and two copies were 0.759 and 0.853 respectively, indicating possible protective effects while that for three copies was 1.604. Conclusions: Based on our study there is no significant link between CYP2D6 gene copy numbers and tamoxifen resistance in women with breast cancer. But more studies considering other influencing factors appear warranted.

• Spatial Information Research
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• v.22 no.1
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• pp.19-26
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• 2014

Recently, ICT environments have been increasingly developed and the pattern of the war also has been changed to NCW. The development of communication and network technology, for example, C4I and TDL(Tactical Data Link), has been prosperous and rapid. But the geospatial intelligence field which is the basis of the network frames relatively has not been developed. The purpose of this paper is to foster the geospatial governance in terms of the defense perspective. In order to do that, this paper deals with the U.S. Intelligence Community(IC) and the U.S. Army Global Information Grid(GIG), LandWarNet and those could be good examples of roles and statuses of geospatial intelligence. IC has been produced essential intelligence which is required for policymakers and military leaders. IC has several stove-piped intelligence process systems which have been separately developed and competed. And so as to complete GIG, the U.S. Army adopted LandWarNet. The U.S. Corps of Engineers organized the Army Geospatial Center(AGC) on 1 October 2009 to support LandWarNet. In order to develop NCW, we should recognize geospatial intelligence as the basis of network framework and make a central leading organization of defense geospatial intelligence. The mission of Korea Defense Geospatial-Intelligence Agency should be changed from producing GEOINT to a strategic GEOINT agency. The Army should organize a laboratory of geospatial intelligence field. The mission of producing GEOINT should be transferred to a geospatial intelligence battalion which is newly organized.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.200-208
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• 2020

The purpose of this study was to investigate and compare health, medical and welfare service providers' and local residents' perception on community care. The participants were 68 service providers and 95 local residents. The data were analyzed using independent t-test and chi-square test. The results showed that the degree of agreement of service providers on the need for policy, and visiting services were higher. Service providers' ability to link local residents with a need for care to community resources was higher, but in the activation of self-help group in community, local residents agreed more. In add budget of policy to health insurance, local residents agreed less. In perception on priority for community care policy, high priorities were preparation of financial resources and care culture. To effectively operate community care policy, it is necessary to establish a care culture through active exchanges for reducing differences in policy and opinions of recipients.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.579-585
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• 2012

This study was carried out to investigate the effect of potassium silicate on the growth and leaf epidermal characteristics of horticultural crops viz., begonia (Begonia semperflorens Link et Otto) 'Super Olympia Red' and 'Super Olympia Rose' and pansy (Viola ${\times}$ wittrockiana Hort.) 'Matrix White Blotch' and 'Matrix Yellow Blotch' in vitro. Seeds after germination were grown on a quarter strength MS medium supplemented with potassium silicate ($K_2SiO_3$) at 0, 100, 200, or $300mg{\cdot}L^{-1}$ and were maintained under a photoperiod of 16 hours at $25^{\circ}C$. Growth parameters such as plant height, root length, chlorophyll content, fresh, and dry weights have been recorded after a growth period of 58 days for begonia and 94 days for pansy. In begonia, fresh weight was significantly greatest in the $200mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment in both 'Super Olympia Red' and 'Super Olympia Rose'. In both pansy cultivars, fresh weight was the greatest in the $200mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment than other treatments. Chlorophyll content was significantly greater in the $100mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment for both the cultivars of begonia. Leaf area significantly increased with the higher concentrations of $K_2SiO_3$ treatment in both cultivars of pansy. Stomatal structures on the leaf epidermis were observed with scanning electron microscopy (SEM). In begonia 'Super Olympia Rose', the structure of stomata were more compact in size in the $300mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment than in the control. Similarly, in pansy 'Matrix White Blotch' the surface of stomata appeared to be smoother in the $300mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment than those wrinkled appearance in the control. The surface of the leaf epidermis appeared to be compact due to Si deposition, and thus results indicated that Si positively affected the growth and biomass production of these species. Our data show that the effect of Si on growth parameters is strongly dependent on cultivar of the plant species tested.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.109-125
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• 2004

In recent decades, microscopic simulation models have become powerful tools to analyze traffic flow on highways and to assist the investigation of level of service. The existing microscopic simulation models simulate an individual vehicle's speed based on a constant free-flow speed dominantly specified by users and driver's behavior models reflecting vehicle interactions, such as car following and lane changing. They set a single free-flow speed for a single vehicle on a given link and neglect to consider the effects of highway design elements to it in their internal simulation. Due to this, the existing models are limitted to provide with identical simulation results on both curved and tangent sections of highways. This paper presents a model developed to estimate the change of free-flow speeds based on highway design elements. Nine neural network models were trained based on the field data collected from seven different freeway curve sections and three different locations at each section to capture the percent changes of free-flow speeds: 100 m upstream of the point of curve (PC) and the middle of the curve. The model employing seven highway design elements as its input variables was selected as the best : radius of curve, length of curve, superelevation, the number of lanes, grade variations, and the approaching free-flow speed on 100 m upstream of PC. Tests showed that the free-flow speeds estimated by the proposed model were statistically identical to the ones from the field at 95% confidence level at each three different locations described above. The root mean square errors at the starting and the middle of curve section were 6.68 and 10.06, and the R-squares at these points were 0.77 and 0.65, respectively. It was concluded from the study that the proposed model would be one of the potential tools introducing the effects of highway design elements to free-flow speeds in simulation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.43-53
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• 2010

The increasing interest in the use of automated photographic equipment in Korea enables to detect speed violation and enforce traffic laws. Since 1996, Korean National Police Agency has been promoting a project for installation of Automated Speed Enforcement (ASE) system aiming at reduction of accidents. Recently, point to point speed cameras operate to measure a driver's average speed across length of road and/or the spot speed at individual camera sites along the road length. In this study, we were analyzed to driver's operating characteristics in point to point speed cameras. The point to point speed camera system has link-long influence on drivers and their speeds despite enforcement being visible only at the start and end of enforced road length. Then, mean and 85th percentile speeds were below speed limit along enforced road length by the two camers. Also, Female drivers were driving at low speed than male drivers along the road length.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.46-51
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• 2013

In this paper, the optimum placement and shape of UHF antenna on the unmanned aerial vehicle (UAV) are analyzed by using the electromagnetic (EM) simulation on the various locations. The FEKO was used for the EM-simulation. In order to reduce the complexity of simulation and minimize the runtime and memory usage, the composite aircraft structure is simplified as the PEC model excluding the radome structure. The simulation was performed on the wing and ventral fin of UAV, and the antenna shape used the monopole, dipole, and bent monopole antennas. When the monopole antenna is mounted under the wing, two antennas need to be mounted under the right and left wings, and those antennas have to be switched as the direction of UAV wing to the line of sight (LOS) data-link (DL) ground antenna. In the case of mounting under the ventral fin, one antenna can be used regardless of the direction of UAV wing to the LOS DL ground antenna. Also, the antenna gain is improved by the blockage reduction. The antenna gain is further improved by using the bent monopole antenna. The optimum solution of UHF antenna placement and shape on UAV is to mount the bent monopole antenna under the ventral fin.