• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.131-131
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• 2010

The power of semiconductor laser diodes has been limited primarily by the heating effects which occur at high optical intensities. The actual limiting event can take one of a number of forms such as. catastrophic optical damage or filamentation. A general approach to this problem is to design a heterostructure which creates a high powered output while maintaining low internal optical intensities. A graded index separate confinement heterostructure (GRIN-SCH) is one such structure that accomplishes the above task. Here, the active region is sandwiched between graded index layers where the index of refraction increases nearer to the active layer. This structure has been shown to yield a high efficiency due to the confinement of both the optical power and carriers, thereby reducing the optical intensity required to achieve higher powers. The optical confinement also reinforces the optical beam quality against high power effects. Quantum dots have long been a desirable option for laser diodes due to the enhanced optical properties associated with the zeroth dimensionality. In our work, we use PICS3D software created by Crosslight Software Inc. to simulate the performance of In0.67A10.33As/A10.2Ga0.8AsquantumdotsusedwithaGRIN-SCH. The simulation tools are used to optimize the GRIN-SCH structure for high efficiency and optical beam quality.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.2
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• pp.56-63
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• 2003

We investigate some implementation factors that affect the performance of multi-rate parallel interference cancellers (PICs) for the international mobile telecommunications-2000 (IMT-2000) 3rd-generation partnership project (3GPP) system. We consider the simple multi-rate PIC [1,2] that can remove effectively multiple access interference (MAI) through block-based detection and sample-based cancellation in asynchronous user environments. The PIC structure has significantly lower complexity as compared with that of the existing scheme, especially as the number of users increases. We analyze the effects of timing error, oversampling rate, unsynchronized users and/or outer-cell interference, and the number of Quantization bits on the PIE performance through extensive computer simulations. The models for such factors and the optimum parameters are drawn. Finally, we evaluate the receiver complexities of the PIC receivers employing using the advanced removal scheme.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.131-141
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• 2005

Molecular-based genetic diversity for a set of 141 accessions of Korean barley cultivars and 24 accessions of foreign exotic cultivars were analyzed using random amplified polymorphic DNAs (RAPDs). Different level of genetic variability was observed with 30 random decamer primers in the Korean barley varieties and breeding lines which were preliminarily classified by morphological (hulled & hulless barley) and end-use (malting barley) and/or by the released periods. A total of 74 RAPD bands were scored, and the number of bands per primer varied from 1 to 7 with an average of 2.74. The hulled barley pool had one more marker genotype per primer than the hulless barley pool. The polymorphic information content (PIC) values based on the band pattern frequencies among genotypes varied depending on genetic pools where mean PICs of hulled, hulless and malting barleys were 0.62, 0.57, and 0.43, respectively. Certain genomic loci amplified by opR04, opF01, opB05, and opC13 were highly polymorphic with PIC>0.8. Patterns and temporal trends of genetic diversity assessed over the period from 1970s to 1990s had a tendency to increase, and in particular, this upward slant was quite clear and significant for the hulless barley pool. In the cluster analysis using genetic similarity matrix calculated from RAPD profiles, two major groups and several small subgroups were classified. Major grouping of materials was not affected by the presence of the husk but by their genetic background and the spike-row type. The validity of information on the genetic diversity and relationships between genotypes will have been reviewed to predict their yield potential.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.28-29
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• 2000

Optical power splitters and/or couplers are important components for optical signal distribution between channels both in wavelength division multiplexing(WDM) systems and photonic integrated circuits(PICs). Since polarization is usually not known after propagation in an optical fiber, passive WDM components have to be polarization insensitivity, Compared to alternatives such as directional couplers or Y-junction splitters, splitters based on multimode interference(MMI) have found a growing interest in recent yens because of their desirable characteristics, such as compact size, low excess loss, wide bandwidth, polarization independence, and relaxed fabrication tolerances$^{(1)}$ . These devices have been fabricated in polymers, silica, or III-V semiconductor materials. A1 $\times$ 4 MMI power splitter on InP materials that were suitable for application in the 1.55-${\mu}{\textrm}{m}$ region$^{(2)}$ . However, the fabrication process of the structure is too complicated and the photolithography tolerance is very tight. Also, a 1 $\times$ 16 InGaAsP/InP MMI power splitter with an excess loss of 2.2dB and a splitting ratio of 1.5dB was demonstrated by using deep etching$^{(3)}$ . The deep etching of the sidewalls through the entire guide layer of the slab waveguide resulted in a number of drawbacks$^{(4)}$ . (omitted)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.957-964
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• 2003

The circulation of unwholesome information such as obscene and violent information is gradually increasing based on the rapid expansion of information communications infrastructure. Those kinds of information are harmful to the adolescents and even cause social problems so that active countermeasure is requited. In order to cope with the spread of unwholesome information, appropriate regulating methods are absolutely in need by establishing or revising information communications-related laws. In this paper, we had analyzed domestic and foreign programs with existing harmful information blocking method, and then designed and implemented a selective blocking program based on Platform for Internet Contents Selection(PICS) by using selective blocking technology based on Internet contents rating system. We also proposed a compromised rating system blocking method that consists of selective filtering function by age and the popular blocking list. The proposed system has advantages in that there would be no increase in network load resulting from blocking list update and inquiry, it is possible to perform active selective filtering considering user's age, and it may introduce self-imposed rating.

• Journal of Animal Science and Technology
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• v.50 no.6
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• pp.733-740
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• 2008

The purpose of this study was to assess the genetic variation and establish the relationship amongst Hanwoo, Angus and Holstein breed. The genetic characteristics and variability within Hanwoo(300), Angus(80) and Holstein(50) were estimated on the basis of relationships determined using the 10 kinds of microsatellite, which is located on different chromosomes. Frequencies of microsatellites markers were used to estimate heterozygosities, polymorphic information content(PIC) and genetic distances. The PICs ranged from 0.604 to 0.872(Hanwoo), from 0.562 to 0.812(Angus) and from 0.471 to 0.828(Holstein). Observed heterozygosity and PIC of Hanwoo are the highest among the analyzed breeds. Additionally, Estimates of genetic distance can be utilized to identify genetic relationships between Hanwoo and the other breed. Genetic distances(0.233) between Hanwoo and Angus was lower than distances between Hanwoo and Holstein(2.283). Also, Genetic distances between Angus and Holstein was shown for(2,400). The other side, each individuals were not ramified to different group and were spread evenly in phylogenetic dendrogram about all the populations.

• Information Systems Review
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• v.12 no.3
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• pp.1-17
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• 2010

IT Systems based on Global Single Instance (GSI) can manage a corporation's internal information, resources and assets effectively and raise business efficiency through consolidation of their business process and productivity. But, It has also dangerous factor that IT system fault failure can cause a state of paralysis of a business itself, followed by huge loss of money. Many of studies have been conducted about fault-tolerance based on using redundant component. The concept of fault tolerance is rather simple but, designing and adopting fault-tolerance system is not easy due to uncertainty of a type and frequency of faults. So, Operational fault management that working after developed IT system is important more and more along with technical fault management. This study proposes the fault management process that including a pre-estimation method using TRM (Technical Reference Model) check point and event rule engine. And also proposes a effect of fault-free process through built fault management system to representative company of Hi-tech industry. After adopting fault-free process, a number of failure decreased by 46%, a failure time decreased by 56% and the Opportunity loss costs decreased by 77%.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.78-86
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• 2017

Humans are provided with a wide range of public benefits from ecosystems and agricultural ecosystems, but the establishment of the horticulture complex could be a space that hampers the public function of the agricultural ecosystem. In this study, we sought to focus the function of landscape creation of agricultural landscape and tried to analyze the landscape of the horticulture complex. Therefore, This study aims to suggest ways to build a greenhouse complex which is being indiscreetly introduced in the agriculture landscape through environmentally-friendly manner and minimize the function of the ecosystem service. We divided the greenhouse complex into two categories of Plastic Greenhouse(v) and Glass Greenhouse(g), and compared them to the Netherland and Japan counterparts. Each image of research areas was selected by 3 pics and polled by a total of 101 people. The results of the Evaluation of Landscape Image are as shown in the figure. Netherland Glass Greenhouse scored 1.80 in terms of 'Neat' which is one of the given 15 adjectives. Study results shows that Korean Plastic Greenhouse landscapes need to endeavor Japanese vinly greenhouses and Dutch glasshouses. Consequently, an analysis on the elements of landscapes including green area, variant elements, separation distance is essential in order to improve our country's greenhouse complex landscapes. In this regard, continuous research is required to improve rural landscapes and harmonize large-scale horticultural facilities into the existing agricultural ecosystem.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.269-282
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• 2021

Following enforcement of the Nagoya Protocol (NP), in which the sovereign rights to genetic resources of countries are recognized, new legal obligations regarding access and benefit-sharing (ABS) that did not exist before have now been imposed on researchers. To implement the NP, many countries are introducing new procedures and regulations when a researcher wants to obtain genetic resources for commercial or noncommercial uses. It is therefore expected that resource-rich countries will adopt strong regulations to protect their genetic resources. In this regard, Korean microbiologists will need to respond to these changes to minimize the potential damages caused by the ABS. This paper reviews the key contents of the NP to raise its awareness among scientific researchers and further presents specific measures to meet the ABS obligations accordingly. For example, Korean researchers, in principle, do not need to acquire Prior Informed Consents (PICs) when they access Korean microbial resources for both commercial or research purposes. Nevertheless, when a foreign culture collection agency such as DSMZ requests a confirmation of compliance with the NP to deposit genetic resources, Korean researchers can also apply for a PIC with the Korean government as an exception. By referring to this article, microbiologists will be able to conduct their research in compliance with the NP while respecting the legal ABS obligations of each resource-providing country.