Pub Date : 2016-03-31DOI: 10.6109/jicce.2016.14.1.045
Ik-Hyun Youn, Kwang Hee Won, Jong-Hoon Youn, J. Scheffler
Gait-based classification has gained much interest as a possible authentication method because it incorporate an intrinsic personal signature that is difficult to mimic. The study investigates machine learning techniques to mitigate the natural variations in gait among different subjects. We incorporated several machine learning algorithms into this study using the data mining package called Waikato Environment for Knowledge Analysis (WEKA). WEKA’s convenient interface enabled us to apply various sets of machine learning algorithms to understand whether each algorithm can capture certain distinctive gait features. First, we defined 24 gait features by analyzing three-axis acceleration data, and then selectively used them for distinguishing subjects 10 years of age or younger from those aged 20 to 40. We also applied a machine learning voting scheme to improve the accuracy of the classification. The classification accuracy of the proposed system was about 81% on average.
基于步态的分类作为一种可能的身份验证方法已经引起了人们的极大兴趣，因为它包含了难以模仿的内在个人签名。该研究调查了机器学习技术，以减轻不同受试者步态的自然变化。我们使用名为Waikato Environment for Knowledge Analysis (WEKA)的数据挖掘包将几种机器学习算法整合到这项研究中。WEKA方便的界面使我们能够应用各种机器学习算法集，了解每种算法是否可以捕获某些独特的步态特征。首先，我们通过分析三轴加速度数据定义了24个步态特征，然后有选择地使用它们来区分10岁或以下的受试者与20至40岁的受试者。我们还应用了机器学习投票方案来提高分类的准确性。该系统的分类准确率平均约为81%。
{"title":"Wearable Sensor-Based Biometric Gait Classification Algorithm Using WEKA","authors":"Ik-Hyun Youn, Kwang Hee Won, Jong-Hoon Youn, J. Scheffler","doi":"10.6109/jicce.2016.14.1.045","DOIUrl":"https://doi.org/10.6109/jicce.2016.14.1.045","url":null,"abstract":"Gait-based classification has gained much interest as a possible authentication method because it incorporate an intrinsic personal signature that is difficult to mimic. The study investigates machine learning techniques to mitigate the natural variations in gait among different subjects. We incorporated several machine learning algorithms into this study using the data mining package called Waikato Environment for Knowledge Analysis (WEKA). WEKA’s convenient interface enabled us to apply various sets of machine learning algorithms to understand whether each algorithm can capture certain distinctive gait features. First, we defined 24 gait features by analyzing three-axis acceleration data, and then selectively used them for distinguishing subjects 10 years of age or younger from those aged 20 to 40. We also applied a machine learning voting scheme to improve the accuracy of the classification. The classification accuracy of the proposed system was about 81% on average.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"24 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132031793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-31DOI: 10.6109/jicce.2016.14.1.009
Hoon Lee
With the introduction of the data-oriented plan for LTE service, one may concerned with the background of the ISP’s policy in charging for LTE services. In this work we investigate the latest usage patterns of voice and data applications for customers over the current mobile network, via which we investigate why mobile operators introduced data-oriented plans. To be specific, we collected the real-field data for the volume of voice and data traffic from the LTE network before the dataoriented plans were introduced. From the collected data we compute the absolute volume as well as the proportion of voice and data applications. From these observations we infer mobile operators’ reasoning behind the decision to introduce dataoriented plans with unlimited voice calls over the mobile network.
{"title":"Why Mobile Operators Introduced Data Plans: An Analysis of Voice and Data Usage Patterns","authors":"Hoon Lee","doi":"10.6109/jicce.2016.14.1.009","DOIUrl":"https://doi.org/10.6109/jicce.2016.14.1.009","url":null,"abstract":"With the introduction of the data-oriented plan for LTE service, one may concerned with the background of the ISP’s policy in charging for LTE services. In this work we investigate the latest usage patterns of voice and data applications for customers over the current mobile network, via which we investigate why mobile operators introduced data-oriented plans. To be specific, we collected the real-field data for the volume of voice and data traffic from the LTE network before the dataoriented plans were introduced. From the collected data we compute the absolute volume as well as the proportion of voice and data applications. From these observations we infer mobile operators’ reasoning behind the decision to introduce dataoriented plans with unlimited voice calls over the mobile network.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121946842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-31DOI: 10.6109/jicce.2016.14.1.001
Cahyo Tri Satrio, Jaeshin Jang
Spectrum sensing in cognitive radio networks allows secondary users to sense the unused spectrum without causing interference to primary users. Cognitive radio requires more accurate sensing results from unused portions of the spectrum. Accurate spectrum sensing techniques can reduce the probability of false alarms and misdetection. In this paper, a two-stage spectrum sensing scheme is proposed for cooperative spectrum sensing in cognitive radio networks. In the first stage, spectrum sensing is executed for each secondary user using energy detection based on double adaptive thresholds to determine the spectrum condition. If the energy value lies between two thresholds, a fuzzy logic scheme is applied to determine the channel conditions more accurately. In the second stage, a fusion center combines the results of each secondary user and uses a fuzzy logic scheme for combining all decisions. The simulation results show that the proposed scheme provides increased sensing accuracy by about 20% in some cases.
{"title":"Two-Stage Spectrum Sensing Scheme Using Fuzzy Logic for Cognitive Radio Networks","authors":"Cahyo Tri Satrio, Jaeshin Jang","doi":"10.6109/jicce.2016.14.1.001","DOIUrl":"https://doi.org/10.6109/jicce.2016.14.1.001","url":null,"abstract":"Spectrum sensing in cognitive radio networks allows secondary users to sense the unused spectrum without causing interference to primary users. Cognitive radio requires more accurate sensing results from unused portions of the spectrum. Accurate spectrum sensing techniques can reduce the probability of false alarms and misdetection. In this paper, a two-stage spectrum sensing scheme is proposed for cooperative spectrum sensing in cognitive radio networks. In the first stage, spectrum sensing is executed for each secondary user using energy detection based on double adaptive thresholds to determine the spectrum condition. If the energy value lies between two thresholds, a fuzzy logic scheme is applied to determine the channel conditions more accurately. In the second stage, a fusion center combines the results of each secondary user and uses a fuzzy logic scheme for combining all decisions. The simulation results show that the proposed scheme provides increased sensing accuracy by about 20% in some cases.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126820083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-31DOI: 10.6109/jicce.2016.14.1.035
Won-Young Uhm, K. Ryu, Sungchan Kim
In this paper, we develop a 94-㎓ single balanced mixer with low conversion loss using planar Schottky diodes on a GaAs substrate. The GaAs Schottky diode has a nanoscale anode with a T-shaped disk that can yield high cutoff frequency characteristics. The fabricated Schottky diode with an anode diameter of 500 ㎚ has a series resistance of 21 Ω, an ideality factor of 1.32, a junction capacitance of 8.03 fF, and a cutoff frequency of 944 GHz. Based on this technology, a 94-㎓ single balanced mixer was constructed. The fabricated mixer shows an average conversion loss of -7.58 ㏈ at an RF frequency of 92.5 ㎓ to 95 ㎓ and an IF frequency of 500 ㎒ with an LO power of 7 ㏈m. The RF-to-LO isolation characteristics were greater than -32 ㏈. These values are considered to be attributed to superior Schottky diode characteristics.
{"title":"Design of a 94-GHz Single Balanced Mixer Using Planar Schottky Diodes with a Nano-Dot Structure on a GaAs Substrate","authors":"Won-Young Uhm, K. Ryu, Sungchan Kim","doi":"10.6109/jicce.2016.14.1.035","DOIUrl":"https://doi.org/10.6109/jicce.2016.14.1.035","url":null,"abstract":"In this paper, we develop a 94-㎓ single balanced mixer with low conversion loss using planar Schottky diodes on a GaAs substrate. The GaAs Schottky diode has a nanoscale anode with a T-shaped disk that can yield high cutoff frequency characteristics. The fabricated Schottky diode with an anode diameter of 500 ㎚ has a series resistance of 21 Ω, an ideality factor of 1.32, a junction capacitance of 8.03 fF, and a cutoff frequency of 944 GHz. Based on this technology, a 94-㎓ single balanced mixer was constructed. The fabricated mixer shows an average conversion loss of -7.58 ㏈ at an RF frequency of 92.5 ㎓ to 95 ㎓ and an IF frequency of 500 ㎒ with an LO power of 7 ㏈m. The RF-to-LO isolation characteristics were greater than -32 ㏈. These values are considered to be attributed to superior Schottky diode characteristics.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133778431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-31DOI: 10.6109/jicce.2016.14.1.040
Y. Yu, S. Lim
The device coupling between the stacked top/bottom field-effect transistors (FETs) in two types of monolithic 3D inverter (M3INV) with/without a metal layer in the bottom tier is investigated, and then the regime of the thickness T ILD and dielectric constant e r of the inter-layer distance (ILD), the doping concentration N d (N a ), and length L g of the channel, and the side-wall length L SW where the stacked FETs are coupled are studied. When N d (N a ) ＜ 10 16 ㎝ -3 and LSW ＜ 20 ㎚, the threshold voltage shift of the top FET varies almost constantly by the gate voltage of the bottom FET, but when N d (N a ) ＞ 10 16 ㎝ -3 or L SW ＞ 20 ㎚, the shift decreases and increases, respectively. M3INVs with T ILD ≥ 50 ㎚ and e r ≤ 3.9 can neglect the interaction between the stacked FETs, but when T ILD or e r do not meet the above conditions, the interaction must be taken into consideration.
研究了两种单片三维逆变器(M3INV)中底部有/没有金属层的层间堆叠场效应晶体管(fet)之间的器件耦合，并研究了层间距离(ILD)、掺杂浓度N d (N a)、通道长度L g和边壁长度L SW的厚度T ILD和介电常数er的变化规律。当N d (N a) < 10 16㎝-3和LSW < 20㎚时，顶部场效应管的阈值电压位移几乎随底部场效应管栅极电压的变化而变化，而当N d (N a) >0 16㎝-3或LSW > 20㎚时，阈值电压位移分别减小和增大。当tild≥50㎚且er≤3.9时，M3INVs可以忽略堆叠fet之间的相互作用，但当tild或er不满足上述条件时，必须考虑相互作用。
{"title":"Device Coupling Effects of Monolithic 3D Inverters","authors":"Y. Yu, S. Lim","doi":"10.6109/jicce.2016.14.1.040","DOIUrl":"https://doi.org/10.6109/jicce.2016.14.1.040","url":null,"abstract":"The device coupling between the stacked top/bottom field-effect transistors (FETs) in two types of monolithic 3D inverter (M3INV) with/without a metal layer in the bottom tier is investigated, and then the regime of the thickness T ILD and dielectric constant e r of the inter-layer distance (ILD), the doping concentration N d (N a ), and length L g of the channel, and the side-wall length L SW where the stacked FETs are coupled are studied. When N d (N a ) ＜ 10 16 ㎝ -3 and LSW ＜ 20 ㎚, the threshold voltage shift of the top FET varies almost constantly by the gate voltage of the bottom FET, but when N d (N a ) ＞ 10 16 ㎝ -3 or L SW ＞ 20 ㎚, the shift decreases and increases, respectively. M3INVs with T ILD ≥ 50 ㎚ and e r ≤ 3.9 can neglect the interaction between the stacked FETs, but when T ILD or e r do not meet the above conditions, the interaction must be taken into consideration.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124696099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.6109/jicce.2015.13.4.264
C. Shin, Jung-Jai Lee, Chai-Yeoung Jung
The chest X-ray image cannot be focused in the same manner that optical lenses are and the resultant image generally tends to be slightly blurred. Therefore, the methods to improve the quality of chest X-ray image have been studied. In this paper, the inherent noises of the input images are suppressed by adding the Laplacian image to the original. First, the chest X-ray image using an Gaussian high pass filter and an optimal high frequency emphasis filter has shown improvements in the edges and contrast of flat areas. Second, using fuzzy logic_histogram equalization, each pixel of the chest X-ray image shows the normal distribution of intensities that are not overexposed. As a result, the proposed method has shown the enhanced edge and contrast of the images with the noise canceling effect.
{"title":"An Enhanced Algorithm for an Optimal High-Frequency Emphasis Filter Based on Fuzzy Logic for Chest X-Ray Images","authors":"C. Shin, Jung-Jai Lee, Chai-Yeoung Jung","doi":"10.6109/jicce.2015.13.4.264","DOIUrl":"https://doi.org/10.6109/jicce.2015.13.4.264","url":null,"abstract":"The chest X-ray image cannot be focused in the same manner that optical lenses are and the resultant image generally tends to be slightly blurred. Therefore, the methods to improve the quality of chest X-ray image have been studied. In this paper, the inherent noises of the input images are suppressed by adding the Laplacian image to the original. First, the chest X-ray image using an Gaussian high pass filter and an optimal high frequency emphasis filter has shown improvements in the edges and contrast of flat areas. Second, using fuzzy logic_histogram equalization, each pixel of the chest X-ray image shows the normal distribution of intensities that are not overexposed. As a result, the proposed method has shown the enhanced edge and contrast of the images with the noise canceling effect.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114505883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.6109/jicce.2015.13.4.248
Sung-Hong Wie, Jaeshin Jang
With the dramatic increase in mobile traffic in recent years, some of the limitations of mobility management frameworks have magnified. The current centralized mobility management (CMM) strategy has various problems, such as a suboptimal routing path, low scalability, signaling overhead, and a single point of failure. To overcome these weaknesses in the CMM strategy, the Internet Engineering Task Force has been discussing distributed mobility management (DMM) strategies. The fundamental concept of a DMM strategy is to distribute the mobility anchors closer to the users. While the distribution of mobility anchors results in low-cost traffic delivery, it increases the signaling cost. To reduce this higher signaling cost, we propose a new DMM strategy applying the pointer forwarding technique. The proposed strategy keeps the existing tunnels and extends the traffic path as much as possible. In this paper, we analyze the performance of the pointer forwarding-DMM strategy and discuss its pros and cons.
{"title":"Distributed Mobility Management Strategy with Pointer Forwarding Technique","authors":"Sung-Hong Wie, Jaeshin Jang","doi":"10.6109/jicce.2015.13.4.248","DOIUrl":"https://doi.org/10.6109/jicce.2015.13.4.248","url":null,"abstract":"With the dramatic increase in mobile traffic in recent years, some of the limitations of mobility management frameworks have magnified. The current centralized mobility management (CMM) strategy has various problems, such as a suboptimal routing path, low scalability, signaling overhead, and a single point of failure. To overcome these weaknesses in the CMM strategy, the Internet Engineering Task Force has been discussing distributed mobility management (DMM) strategies. The fundamental concept of a DMM strategy is to distribute the mobility anchors closer to the users. While the distribution of mobility anchors results in low-cost traffic delivery, it increases the signaling cost. To reduce this higher signaling cost, we propose a new DMM strategy applying the pointer forwarding technique. The proposed strategy keeps the existing tunnels and extends the traffic path as much as possible. In this paper, we analyze the performance of the pointer forwarding-DMM strategy and discuss its pros and cons.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127136772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.6109/jicce.2015.13.4.275
Min-Chul Lee, Kotaro Inoue, N. Konishi, Joon-Jae Lee
There are several methods to record three dimensional (3D) information of objects such as lens array based integral imaging, synthetic aperture integral imaging (SAII), computer synthesized integral imaging (CSII), axially distributed image sensing (ADS), and axially distributed stereo image sensing (ADSS). ADSS method is capable of recording partially occluded 3D objects and reconstructing high-resolution slice plane images. In this paper, we present a computational method for depth extraction of partially occluded 3D objects using ADSS. In the proposed method, the high resolution elemental stereo image pairs are recorded by simply moving the stereo camera along the optical axis and the recorded elemental image pairs are used to reconstruct 3D slice images using the computational reconstruction algorithm. To extract depth information of partially occluded 3D object, we utilize the edge enhancement and simple block matching algorithm between two reconstructed slice image pair. To demonstrate the proposed method, we carry out the preliminary experiments and the results are presented.
{"title":"Depth Extraction of Partially Occluded 3D Objects Using Axially Distributed Stereo Image Sensing","authors":"Min-Chul Lee, Kotaro Inoue, N. Konishi, Joon-Jae Lee","doi":"10.6109/jicce.2015.13.4.275","DOIUrl":"https://doi.org/10.6109/jicce.2015.13.4.275","url":null,"abstract":"There are several methods to record three dimensional (3D) information of objects such as lens array based integral imaging, synthetic aperture integral imaging (SAII), computer synthesized integral imaging (CSII), axially distributed image sensing (ADS), and axially distributed stereo image sensing (ADSS). ADSS method is capable of recording partially occluded 3D objects and reconstructing high-resolution slice plane images. In this paper, we present a computational method for depth extraction of partially occluded 3D objects using ADSS. In the proposed method, the high resolution elemental stereo image pairs are recorded by simply moving the stereo camera along the optical axis and the recorded elemental image pairs are used to reconstruct 3D slice images using the computational reconstruction algorithm. To extract depth information of partially occluded 3D object, we utilize the edge enhancement and simple block matching algorithm between two reconstructed slice image pair. To demonstrate the proposed method, we carry out the preliminary experiments and the results are presented.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127018712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.6109/jicce.2015.13.4.257
Hoshik Lee, Seong G. Kim
In this study, organic field-effect transistors (OFETs) using a copper phthalocyanine (CuPc) material as an active layer and SiO₂ as a gate insulator were fabricated with varying active layer thicknesses and channel lengths. Further, using a thermal evaporation method in a high-vacuum system, we fabricated a CuPc FET device of the top-contact type and used Au materials for the source and drain electrodes. In order to discuss the channel formation and FET characteristics, we observed the typical current–voltage characteristics and calculated the threshold voltage of the CuPc FET device. We also found that the capacitance reached approximately 97 pF at a negative applied voltage and increased upon the accumulation of carriers at the interface of the metal and the CuPc material. We observed the typical behavior of a FET when used as an n-channel FET. Moreover, we calculated the threshold voltage to be about 15–20 V at V DS = –80 V.
{"title":"Threshold Voltage Properties of OFET with CuPc Active Material","authors":"Hoshik Lee, Seong G. Kim","doi":"10.6109/jicce.2015.13.4.257","DOIUrl":"https://doi.org/10.6109/jicce.2015.13.4.257","url":null,"abstract":"In this study, organic field-effect transistors (OFETs) using a copper phthalocyanine (CuPc) material as an active layer and SiO₂ as a gate insulator were fabricated with varying active layer thicknesses and channel lengths. Further, using a thermal evaporation method in a high-vacuum system, we fabricated a CuPc FET device of the top-contact type and used Au materials for the source and drain electrodes. In order to discuss the channel formation and FET characteristics, we observed the typical current–voltage characteristics and calculated the threshold voltage of the CuPc FET device. We also found that the capacitance reached approximately 97 pF at a negative applied voltage and increased upon the accumulation of carriers at the interface of the metal and the CuPc material. We observed the typical behavior of a FET when used as an n-channel FET. Moreover, we calculated the threshold voltage to be about 15–20 V at V DS = –80 V.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131464377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.6109/jicce.2015.13.4.221
Hiep-Vu Van, Insoo Koo
Spectrum sensing plays an essential role in a cognitive radio network, which enables opportunistic access to an underutilized licensed spectrum. In conventional cooperative spectrum sensing (CSS), all cognitive users (CUs) in the network spend the same amount of time on spectrum sensing and waste time in remaining silent when other CUs report their sensing results to the fusion center. This problem is solved by the superposition cooperative spectrum sensing (SPCSS) scheme, where the sensing time of a CU is extended to the reporting time of the other CUs. Subsequently, SPCSS assigns the CUs different sensing times and thus affects both the sensing performance and the throughput of the system. In this paper, we propose an algorithm to determine the optimal sensing time of each CU for SPCSS that maximizes the achieved system throughput. The simulation results prove that the proposed scheme can significantly improve the throughput of the cognitive radio network compared with the conventional CSS.
{"title":"Optimal Sensing Time for Maximizing the Throughput of Cognitive Radio Using Superposition Cooperative Spectrum Sensing","authors":"Hiep-Vu Van, Insoo Koo","doi":"10.6109/jicce.2015.13.4.221","DOIUrl":"https://doi.org/10.6109/jicce.2015.13.4.221","url":null,"abstract":"Spectrum sensing plays an essential role in a cognitive radio network, which enables opportunistic access to an underutilized licensed spectrum. In conventional cooperative spectrum sensing (CSS), all cognitive users (CUs) in the network spend the same amount of time on spectrum sensing and waste time in remaining silent when other CUs report their sensing results to the fusion center. This problem is solved by the superposition cooperative spectrum sensing (SPCSS) scheme, where the sensing time of a CU is extended to the reporting time of the other CUs. Subsequently, SPCSS assigns the CUs different sensing times and thus affects both the sensing performance and the throughput of the system. In this paper, we propose an algorithm to determine the optimal sensing time of each CU for SPCSS that maximizes the achieved system throughput. The simulation results prove that the proposed scheme can significantly improve the throughput of the cognitive radio network compared with the conventional CSS.","PeriodicalId":272551,"journal":{"name":"J. Inform. and Commun. Convergence Engineering","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133665024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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