• Current Optics and Photonics
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• v.4 no.3
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• pp.174-185
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• 2020

Multiscattering occurs when a laser transmits into dense atmosphere targets (e.g. fogs, smoke or clouds), which can cause depolarization effects even though the scattering particles are spherical. In addition, multiscattering effects have additional information about microphysical properties of scatterers. Thus, multiscattering can be utilized to study the microphysical properties of the liquid water cloud. In this paper, a Monte Carlo method was used to simulate multi-scattering transmission properties of Lidar signals in the cloud. The results showed the slope of the degree of linear polarization (SLDLP) can be used to invert the extinction coefficient, and then the cloud effective size (CES) and the liquid water content (LWC) may be easily obtained by using the extinction coefficient and saturation of the degree of linear polarization (SADLP). Based on calculation results, a microphysical properties inversion method for a liquid cloud was presented. An innovative multiscattering polarization Lidar (MSPL) system was constructed to measure the LWC and CES of the liquid cloud, and a new method based on the polarization splitting ratio of the Polarization Beam Splitter (PBS) was developed to calibrate the polarization channels of MSPL. By analyzing the typical observation data of MSPL observation in the northern suburbs of Nanjing, China, the LWC and CES of the liquid water cloud were obtained. Comparisons between the results from the MSPL, MODIS and the Microwave radar data showed that, the microphysical properties of liquid cloud could be retrieved by combining our MSPL and the inversion method.

• The KIPS Transactions:PartC
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• v.13C no.3 s.106
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• pp.339-344
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• 2006

Secure delivery of multicast data can be achieved with the use of a group key for data encryption in mobile ad hoc network (MANET) applications based on the group communication. However, for the support of dynamic group membership, the group key has to be updated for each member joining/leaving and, consequently, a mechanism distributing an updated group key to members is required. The two major categories of the group key distribution mechanisms proposed for wired networks are the naive and the tree-based approaches. The naive approach is based on unicast, so it is not appropriate for large group communication environment. On the other hand, the tree-based approach is scalable in terms of the group size, but requires the reliable multicast mechanism for the group key distribution. In the sense that the reliable multicast mechanism requires a large amount of computing resources from mobile nodes, the tree-based approach is not desirable for the small-sized MANET environment. Therefore, in this paper, we propose a new key distribution protocol, called the proxy-based key management protocol (PROMPT), which is based on the naive approach in the small-sized MANET environment. PROMPT reduces the message overhead of the naive through the first-hop grouping from a source node and the last-hop grouping from proxy nodes using the characteristics of a wireless channel.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1127-1136
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• 2003

Estimation of software project cost, effort and duration in the early stage of software development cycle is a difficult and key problem in software engineering. Most of models estimate the development effort using the function point that is measured from the requirement specification. This paper presents optimal team size and duration prediction based on function point in order to provide information that can be used as a guide in selecting the most Practical and productive team size for a software development project. We introduce to productive metrics and cost for decision criteria of ideal team size and duration. The experimental is based on the analysis of 300 development and enhancement software project data. These data sets are divide in two subgroups. One is a development project; the other is a maintenance project. As a result of evaluation by productivity and cost measured criteria in two subgroups, we come to the conclusion that the most successful projects has small teams and minimum duration. Also, I proposed that predictive model for team sire and duration according to function point size based on experimental results. The presented models gives a criteria for necessary team site and duration according to the software size.

• Animal Bioscience
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• v.35 no.4
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• pp.511-516
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• 2022

Objective: A genomic region associated with a particular phenotype is called quantitative trait loci (QTL). To detect the optimal F₂ population size associated with QTLs in native chicken, we performed a simulation study on F₂ population derived from crosses between two different breeds. Methods: A total of 15 males and 150 females were randomly selected from the last generation of each F₁ population which was composed of different breed to create two different F₂ populations. The progenies produced from these selected individuals were simulated for six more generations. Their marker genotypes were simulated with a density of 50K at three different heritability levels for the traits such as 0.1, 0.3, and 0.5. Our study compared 100, 500, 1,000 reference population (RP) groups to each other with three different heritability levels. And a total of 35 QTLs were used, and their locations were randomly created. Results: With a RP size of 100, no QTL was detected to satisfy Bonferroni value at three different heritability levels. In a RP size of 500, two QTLs were detected when the heritability was 0.5. With a RP size of 1,000, 0.1 heritability was detected only one QTL, and 0.5 heritability detected five QTLs. To sum up, RP size and heritability play a key role in detecting QTLs in a QTL study. The larger RP size and greater heritability value, the higher the probability of detection of QTLs. Conclusion: Our study suggests that the use of a large RP and heritability can improve QTL detection in an F₂ chicken population.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.239-254
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• 2007

Ubiquitous computing supports environment to freely connect to network without restrictions of place and time. This environment enables easy access and sharing of information, but because of easy unauthorized accesses, specified security policy is needed. Especially, ubiquitous sensor network devices use limited power and are small in size, so, many restrictions on policies are bound to happen. This paper proposes double-key based light weight security protocol, independent to specific sensor OS, platform and routing protocol in ubiquitous sensor network. The proposed protocol supports safe symmetric key distribution, and allows security manager to change and manage security levels and keys. This had a strong merit by which small process can make large security measures. In the performance evaluation, the proposed light weight security protocol using double-key in ubiquitous sensor network allows relatively efficient low power security policy. It will be efficient to ubiquitous sensor network, such as smart of ace and smart home.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.7
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• pp.602-609
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• 2018

This paper proposes the hybrid crypto-system for fast video data encryption of UAV(Unmanned Aerial Vehicle) under the LTE(Long-Term Evolution) wireless communication environment. This hybrid crypto-system is consisted of ECC(Elliptic Curve Cryptography) public key algorithm and LEA(Light-weight Encryption Algorithm) symmetric key algorithm. ECC is a faster public key algorithm with the same security strength than RSA(Rivest Shamir Adleman), and Korean standard LEA with the same key size is also a faster symmetric key algorithm than AES(Advances Encryption Standard). We have implemented this hybrid crypto-system using OpenSSL, OpenCV and Socket programs under the Swarm 8-UAV. We have shown the efficient adaptability of this hybrid crypto-system for the real-time swarm UAV through the experiments under the LTE communication environment.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3763-3766
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• 2012

Background: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate, and the role of the MTHFR C677T polymorphism in pancreatic carcinogenesis is still controversial. Methods: A literature search was performed using Pubmed and CNKI databases for published studies through May 2012. We performed a meta-analysis of all relevant case-control studies that examined the association between MTHFR C677T polymorphism and pancreatic cancer risk. Results: Finally, 9 individual case-control studies with a total of 1,299 pancreatic cancer cases and 2,473 controls were included into this meta-analysis. Results: This metaanalysis showed there was an obvious association between MTHFR C677T polymorphism and pancreatic cancer risk in East Asians (for allele model, OR = 1.67, 95%CI 1.11-2.51; For homozygote model, OR = 2.77, 95%CI 1.40-5.48; for recessive model, OR = 1.96, 95%CI 1.54-2.50; for dominant model, OR = 2.11, 95%CI 1.01-4.41). However, no significant association was found in Caucasians. Conclusions: The MTHFR C677T polymorphism is associated with pancreatic cancer risk, and a race-specific effect may exist in this association. More studies with a larger sample size are needed to further clarify this association.

• BMB Reports
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• v.38 no.4
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• pp.414-419
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• 2005

The production of recombinant antibodies has been generally recognized as time-consuming and labor-intensive. The aim of our study is to construct mammalian expression vectors containing the cDNA encoding the human constant regions and murine variable regions to massively and cost-effectively produce full-length chimeric antibodies. Unique restriction sites flanking the Ig variable region were designed to allow for the replacement of variable regions generated by PCR. Western blot analysis of the chimeric antibodies revealed that the expressed products were of the predicted size, structure and specificity. The usefulness of the vectors was confirmed by construction of human-mouse chimeric antibody-HCAb which secretes murine antibody against the human colorectal cancer. Selected in medium containing gradually increasing methotrexate (MTX), clones with increased expression of the product gene can be efficiently generated. The secretion of recombinant chimeric antibody-HCAb yielded $30\;pg\;cell^{-1}\;day^{-1}$ at $10^{-6}\;M$ MTX. With this high-level expression from pools, the convenient and rapid production of over 100 milligram amounts per liter of recombinant antibodies may be achieved, which indicates the significant roles of pYR-GCEVH and pYR-GCEVL in the production of chimeric antibodies.

• The korean journal of orthodontics
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• v.50 no.2
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• pp.86-97
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• 2020

Objective: To propose a three-dimensional (3D) method for evaluating temporomandibular joint (TMJ) changes during Twin-block treatment. Methods: Seventeen patients with Class II division 1 malocclusion treated using Twin-block and nine untreated patients with a similar malocclusion were included in this research. We collected their cone beam computed tomography (CBCT) data from before and 8 months after treatment. Segmentations were constructed using ITK-SNAP. Condylar volume and superficial area were measured using 3D Slicer. The 3D landmarks were identified on CBCT images by using Dolphin software to assess the condylar positional relationship. 3D models of the mandible and glenoid fossa of the patients were constructed and registered via voxel-based superimposition using 3D Slicer. Thereafter, skeletal changes could be visualized using 3DMeshMetric in any direction of the superimposition on a color-coded map. All the superimpositions were measured using the same scale on the distance color-coded map, in which red color represents overgrowth and blue color represents resorption. Results: Significant differences were observed in condylar volume, superficial area, and condylar position in both groups after 8 months. Compared with the control group (CG), the Twin-block group exhibited more obvious condyle-fossa modifications and joint positional changes. Moreover, on the color-coded map, more obvious condyle-fossa modifications could be observed in the posterior and superior directions in the Twin-block group than in the CG. Conclusions: We successfully established a 3D method for measuring and evaluating TMJ changes caused by Twin-block treatment. The treatment produced a larger condylar size and caused condylar positional changes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1828-1847
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• 2014

Coordinated multi-point (CoMP) transmission has been regarded as a potential technology for LTE-Advanced. In frequency division duplexing systems, channel quantization is applied for reporting channel state information (CSI). Considering the dynamic number of cooperation base stations (BSs), asymmetry feature of CoMP channels and high searching complexity, simply increasing the size of the codebook used in traditional multiple antenna systems to quantize the global CSI of CoMP systems directly is infeasible. Per-cell codebook based channel quantization to quantize local CSI for each BS separately is an effective method. In this paper, the theoretical upper bounds of system throughput are derived for two codeword selection schemes, independent codeword selection (ICS) and joint codeword selection (JCS), respectively. The feedback overhead and selection complexity of these two schemes are analyzed. In the simulation, the system throughput of ICS and JCS is compared. Both analysis and simulation results show that JCS has a better tradeoff between system throughput and feedback overhead. The ICS has obvious advantage in complexity, but it needs additional phase information (PI) feedback for obtaining the approximate system throughput with JCS. Under the same number of feedback bits constraint, allocating the number of bits for channel direction information (CDI) and PI quantization can increase the system throughput, but ICS is still inferior to JCS. Based on theoretical analysis and simulation results, some recommendations are given with regard to the application of each scheme respectively.