• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.8
• /
• pp.733-738
• /
• 2013

In this paper, we consider a physical layer security of an amplify-and-forward (AF) transmission in a presence of an eavesdropper in a wiretap channel. The proposed wiretap channel consists of a source, a destination, a relay, and an eavesdropper. Specifically, we consider that the relay has multiple antennas to exploit a diversity gain and a receive/transmit antenna selection schemes are applied to maximize a signal-to-noise ratio. In a practical point of view, we focus on the practical scenario where the relay does not have any channel state information of the eavesdropper while performing an AF protocol at the relay. For a secrecy performance analysis, we analyze a secrecy outage probability of the proposed system in one-integral form and verify our analysis with the computer-based simulation.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.1 no.1
• /
• pp.22-30
• /
• 2020

Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested.

• Korean Journal of Plant Resources
• /
• v.17 no.3
• /
• pp.265-271
• /
• 2004

Genetic variation is the basis of crop improvement. Limited genetic diversity in a crop species may restrict the amount of genetic improvement that can be achieved through plant breeding. Soybean is one of the world's most important crops. A potential source of genetic variability for the cultivated soybean is the wild species G. soja Sieb. ＆amp; Zucc. Amplified fragment length polymorphism (AFLP) analysis is a PCR-based technique, which can detect a 10-fold greater nubmer of loci than other DNA marker analysis. Twenty cultivated soybeans and two-hundred wild soybeans were used to determine genetic vatiations by AFLPs and evaluate the usefulness of AFLPs as DNA markers. Six-hundred and ten fragments were detected with an average of 56 AFLP fragments produced per primer in a total of 11 AFLP primer pairs. The number of polymorphic loci detected per primer ranged from 7 to 20 and the polymorphism was greater in wild than in cultivated soybean. F$_2$ segregation analysis of four AFLP fragments in combination of Hwaeomputkong ${\times}$ PI 417479 indicated that they segregate as stable Mendelian loci with 3 : 1. This results strongly suggest that the AFLP analysis is a good technique for the detection of genetic polymorphism in a wide plant species.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.2
• /
• pp.60-66
• /
• 2008

In this paper, a new subcarrier-based handover scheme which exploits different channel gains of subcarriers in downlink OFDMA cellular systems. In this handover scheme, mobile users can obtain diversity gain by subcarrier selection. Feedback for unselected subcarriers reduces interference. The capacity enhancement by the handover scheme is originated from the following two characteristics of OFDMA systems. One is that interference per subcarrier is proportional to the traffic load. The other is that every subcarrier has different channel gain ?? 새 the Rayleigh fading channel. Therefore, selecting subcarriers with stronger channel gains results in diversity gain. Simulation results confirm that the proposed handover scheme improves the capacity of the OFDMA systems by reducing 24 percentage of the outage probability.

• KSBB Journal
• /
• v.30 no.6
• /
• pp.257-267
• /
• 2015

Insects are the most successful organisms on earth in terms of their diversity and adaptability. Insect biotechnology using this insect resource is an emerging area for future biotechnology with various applications. Insect resources have long been used to make food and/or functional food, feed, cosmetics as well as medicine and industrial ingredients. Recently, one of the most well-known industrial material from insect is spider silk that could be commercialize in near future. The insect cell lines have been used to express recombinant proteins that were difficult to be functional expression. For public purpose, while, the insect could be good amenity source and plant farming, so leisure resource. Only the interdisciplinary research will guarantee the successful story for insect biotechnology. And biochemical engineers should used insect as a bioresource for new products with applications in medicine, agriculture, and industrial biotechnology in near future. This review will cover state-of-the art of this field and the research and application areas of insect biotechnology and the possible role of biochemical engineer for the development of the future biotechnology using this bioresource.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2007.04a
• /
• pp.451-454
• /
• 2007

There is an inseparable relation between human race and engineering work. As world developed into highly industrialized society, a diversity of large structures is being built up correspondently to limited topographical circumstance. Though large structures are national establishments which provide us with convenience of life, there are some disastrous possibilities which were never predicted such as ground subsidence and degradation. It is very difficult to analyze the volume of total metamorphosis with the relative displacement measurement system which is now used and it is impossible to know whether there is structural metamorphosis within a permissible range of design or not. In this research with an object of 13-year-old earthen dam, through generating point-cloud which has 3D spatial coordinates(x, y, z) of this dam by means of 3D Laser Scanning, we can get real configuration data of slanting surface of this dam with this method of getting a number of 3D spatial coordinates(x, y, z). It gives 3D spatial model to us and we can get various information of this dam such as the distance of slanting surface of dam, dimensions and cubic volume. It can be made full use of as important source material of reinforcement and maintenance works to detect previously the bulging of the dam through this research.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.16 no.1
• /
• pp.181-191
• /
• 2013

The design process of ecological and environmental detention system located in the housing district of Sinjeong 3-jigu in Seoul are as follows. At stage one, a new dispersal detention was created in the neighborhood park located near the originally planned detention. From this, the amount of storage of this dispersal detention system was enlarged from $28,337m^3/d$, the initial storage amount, to $33,606m^3/d$ as the post storage amount, responsible to the amount of rainfall which happens every 100 years. In particular, the SSB (Sustainable Structured wetland Biotop) system, which was the New Excellent Technology verified by the Ministry of Environment (No. 258) was applied to enhance ecological functioning and water quality with the detention as a constructed wetland. At stage two, the treatment plans for non-point pollutant source occurred at the initial period of rain, flowing into the detention system were built for purifying the water of the retention pond at the base of the detentions, and the water-circulation system was designed at the dispersal detentions on the period of regular rainfalls. The non-point pollutant source flowing into detention site was calculated as $11,699m^3/d$ flowing down from seven small watersheds, which occurred at the initial period of rain. In particular the SSB systems improved the average efficiency of the water processing performance to BOD 60%, SS 90%, T-N 30%, T-P 60%. At stage three, the ecological network and biological diversity were strongly considered so that it brought the residents with amenity places. In particular, the dispersal detentions were successfully designed to restore the ecological habitat of endangered plant and animal species such as narrow-mouthed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.1C
• /
• pp.1-7
• /
• 2010

In this paper, the performance of the soft-decision-and-forward (SDF) protocol in the cooperative communication network with one source, one relay, and one destination, where each node has two transmit and receive antennas, is analyzed in terms of the bit error rate (BER) obtained from the pairwise error probability (PEP). For the slow-varying Rayleigh fading channel, the optimal and suboptimal power allocation ratios are determined without feedback. The optimal power allocation can be obtained by minimizing the average PEP. For the tractability, an alternative strategy of maximizing the product SNR of direct and relay links, which we call the suboptimal power allocation, is considered. Through the numerical analysis, we show that the performance gap between the suboptimal and the optimal power allocation is negligible in the high SNR region.

• Journal of Korean Medical classics
• /
• v.29 no.4
• /
• pp.75-94
• /
• 2016

Objectives : The uterus plays an important role in the woman's body. In Korean Medical literature, the uterus is mentioned in various contexts according to different perspectives on its meaning and function. An examination of these various contexts is crucial in understanding the meaning of the uterus and to better understand and approach woman's body. Methods : Aside from the most widely used term Jagung(子宮), there were various terms used to refer to the uterus. Based on a list of these terms, the Siku Qianshu collection of medical literatures was investigated. Contents related to the definition, shape, location, function were extracted and examined. Results : Among the findings, first, there were various terms referring to the uterus similar to contemporary understanding. Some of them referred to the uterus as a whole, while others referred to specific parts, one of which is the placenta. Some reflected a broader perspective on the meaning of the uterus. Second, the functions of the uterus could be summarized as gate keeping, and the maintenance of uterine environment that is related to menstruation, pregnancy, and childbirth. Third, based on the examination of the meaning of the uterus and its functions, perspectives on the uterus in Korean Medicine could be summarized into two. Conclusions : One viewed uterus as an organ dedicated to reproduction, similar to today's common understanding. According to this view, uterus is a special organ specific to women, which functions as an incubator for the fetus. The other viewed the uterus as an intangible source of life in the woman's body. As a general source of life to all human beings, it is not a passive organ but functions as an active source in woman's life phenomena. The two perspectives are not in conflict, but rather reflect the broad range of thought on the concept of the uterus in Korean Medicine. In today's biomedical society, the diversity and flexibility of these perspectives could shed light on medical practices that have resulted from extreme views on the woman's body.

• 한국균학회소식:학술대회논문집
• /
• 2015.11a
• /
• pp.11-11
• /
• 2015

A total of sixty-six samples of Nuruk, a fermention starter used to make the Korean traditional rice wine, Makgeolli, were collected from central and southern regions of Korea in 2013 and 2014. We classified two groups of the Nuruk samples, "commercial" and "home-made", according to the manufacturing procedure and purpose of use. Commercial Nuruks were made in a controlled environment where the temperature and humidity are fixed and the final product is supplied to Makgeolli manufacturers. Home-made Nuruks were made under uncontrolled conditions in the naturally opened environment and were intended for use in the production of small amounts of home-brewed Makgeolli. We obtained more than five hundred isolates including filamentous fungi and yeasts from the Nuruk samples followed by identification of fungal species. Also we stored glycerol stocks of each single isolate at $-70^{\circ}C$. We identified the species of each isolate based on the sequences of ITS regions amplified with two different universal primer pairs. We also performed morphological characterization of the filamentous fungi and yeast species through observations under the microscope. We investigated the major fungal species of commercial and home-made Nuruks by counting the colony forming units (CFU) and analyzing the occurrence tendency of fungal species. While commercial Nuruks contained mostly high CFU of yeasts, home-made Nuruks showed relatively high occurrence of filamentous fungi. One of the representative Nuruk manufacturers used both domestic wheat bran and imported ones, mainly from US, as raw material. Depending on the source of ingredient, the fungal diversity was somewhat different. Another commercial Nuruk sample was collected twice, once in 2013 and again in 2014, and showed different diversity of fungal species in each year. Nuruks obtained from the southern regions of Korea and Jeju island showed high frequency of yeast such as Saccharomycopsis fibuligera and Pichia species as well as unique filamentous fungus, Monascus species. S. fibuligera was easily found in many Nuruk samples with high CFU. The major filamentous fungi were Aspergillus, Lichtheimia, Mucor and Penicillium species. In order to further our understanding of the isolates and their potential industrial applications, we assayed three enzymes, alpha amylase, glucoamylase and acid protease from 140 isolates out of about five hundred isolates and selected about 10 excellent strains with high enzyme activities. With these fungal isolates, we will perform omics analyses including genomics, transcriptomics, metabolic pathway analyses, and metabolomics followed by whole genome sequencing of unique isolates associated with the basic research of Nuruk and that also has applications in the Makgeolli making process.