• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.27-35
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• 2021

NAND flash memory-based SSD needs an internal software, Flash Translation Layer(FTL) to provide traditional block device interface to the host because of its physical constraints, such as erase-before-write and large erase block. However, because useful host-side information cannot be delivered to FTL through the narrow block device interface, SSDs suffer from a variety of problems such as increasing garbage collection overhead, large tail-latency, and unpredictable I/O latency. Otherwise, the new type of SSD, open-channel SSD exposes the internal structure of SSD to the host so that underlying NAND flash memory can be managed directly by the host-level FTL. Especially, I/O data classification by using host-side information can achieve the reduction of garbage collection overhead. In this paper, we propose a new scheme to reduce garbage collection overhead of open-channel SSD by separating the journal from other file data for the journaling filesystem. Because journal has different lifespan with other file data, the Write Amplification Factor (WAF) caused by garbage collection can be reduced. The proposed scheme is implemented by modifying the host-level FTL of Linux and evaluated with both Fio and Filebench. According to the experiment results, the proposed scheme improves I/O performance by 46%~50% while reducing the WAF of open-channel SSDs by more than 33% compared to the previous one.

• Journal of Plant Biology
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• v.32 no.2
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• pp.67-78
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• 1989

Hybridization of DNA isolated from leaves of Russet Burbank potato with tomato cDNA as a probe revealed the presence of about ten inhibitor 1 genes in the genome. Screening of a genomic library of Russet Burbank potato resulted in isolation of seven different genomic clones carrying inhibitor I genes. One of the genomic clones, clone 2, contained two EcoRI fragments of 3.4 and 1.8 kb in size, respectively, which were hybridized with the probe. The nucleotide sequence of parts of the hybridizing EcoRI fragments revealed that they contain a complete gene which codes for an open reading frame of 107 amino acids. It is interrupted by two intervening sequences of 502 and 493 bp, situated at the positions of codons 17 and 43, respectively, of the open reading frame. Putative regulatory sequences, TATAAA and CCACT, were found at the 5' flanking region. In addition, a copy of a 100 bp repeat found at a tomato inhibitor I gene was identified.

• Journal of The Korean Astronomical Society
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• v.28 no.2
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• pp.119-137
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• 1995

The $UBVI_{KC}$ CCD photometry was performed in the central region(${\sim}20'{\times}20'$) of the extremely young open cluster IC1805. Member stars were selected in the (B-V)-(U-B) and (V-I)-(B-V) color-color planes. Applying recent stellar evolutionary models, we derived the age, age-spread, and initial mass function(IMF) of the cluster. IC1805 was found to be an extremely young($t_{age}{\sim}1.5Myr$) and has a flat IMF with the slope of ${\Gamma}=-1.0{\pm}0.2$.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.714-717
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• 2013

스마트폰의 대중화로 현재 앱스토어에는 다양한 어플리케이션들이 나오고 있다. 이와 같이 급속하게 발전하는 시대임에도 불구하고 모바일디바이스에서 웹페이지 또는 어플리케이션 으로 확인 할 수 있는 표준정보의 부재가 심각하다. 본 논문에서는 확인하기도 힘들고 활용하기도 어려운 기술표준 관련 정보를 공공안내그림표지 OpenAPI를 활용하여 보다 쉽게 이용 가능한 iOS 기반 스마트폰 어플리케이션을 설계 및 구현한다.

• Journal of Internet Computing and Services
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• v.18 no.2
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• pp.1-11
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• 2017

There are two kinds of wireless network access to a certain place by using smart devices - 1) open (anonymous) - access and 2) user-authorized access. The open-access is a non-authorization connection method which does not need to require Smart device's user authorized information. It means open-access use only user's SSID (Service Set Identifier) information to access the wireless AP devices following public wireless network standard. This access mechanism is not suitable to use all of public wireless networks because users have to get all wireless network information around them. As a result, huge data for smart devices should be one of the most critical overload problems for them. Secondly, the user-authorized access method uses wireless network information (SSID and password) chosen by the users. So, the users have to remember and use the network access information data manually whenever accessing the network. Like open-access, this access method also has the operational and inconvenient problem for the users - manually inputting access information whenever connecting to the network. To overcome this problem in both schemes, we propose two improved wireless network access methods: 1) the implementation of automatic AP connection mechanism using user-authorization and iBeacon messages, and 2) SSID registration form for public wireless networks.

• Honam Mathematical Journal
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• v.35 no.4
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• pp.707-716
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• 2013

The present paper consists of two parts. Since the recent paper [4] proved that an Alexandroff $T_0$-space is a semi-$T_{\frac{1}{2}}$-space, the first part studies semi-open and semi-closed structures of the Khalimsky nD space. The second one focuses on the study of a relation between the LS-property of ($SC^{n_1,l_1}_{k_1}{\times}SC^{n_2,l_2}_{k_2}$, k) relative to the simple closed $k_i$-curves $SC^{n_i,l_i}_{k_i}$, $i{\in}\{1,2\}$ and its normal k-adjacency. In addition, the present paper points out that the main theorems of Boxer and Karaca's paper [3] such as Theorems 4.4 and 4.7 of [3] cannot be new assertions. Indeed, instead they should be attributed to Theorems 4.3 and 4.5, and Example 4.6 of [10].

• Journal of Elementary Mathematics Education in Korea
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• v.1 no.1
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• pp.17-32
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• 1997

Open education is carried out and studied in both phases of theory and practice in Korean elementary schools in these days. 1 introduced three open teaching and learning methods which we can use practically in elementary school mathematics education. They are the teaching and learning by open-end-approach, From problems to problems and Problem posing. First, I illustrate each meaning of three teaching and learning methods. Next, I presented the concrete plans of each teaching and learning method, and exhibited some examples of students' own works.

• Journal of Information Science Theory and Practice
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• v.3 no.2
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• pp.6-15
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• 2015

Since the advent of Linked Data (LD) as a method for building webs of data, there have been many attempts to apply and implement LD in various settings. Efforts have been made to convert bibliographic data in libraries into Linked Data, thereby generating Library Linked Data (LLD). However, when memory institutions have tried to link their data with external sources based on principles suggested by Tim Berners-Lee, identifying appropriate vocabularies for use in describing their bibliographic data has proved challenging. The objective of this paper is to discuss the potential role of Linked Open Vocabularies (LOV) in providing better access to various open datasets and facilitating effective linking. The paper will also examine the ways in which memory institutions can utilize LOV to enhance the quality of LLD and LLD-based ontology design.

• Korean Journal of Materials Research
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• v.22 no.6
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• pp.309-315
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• 2012

Metal foam has many excellent properties, such as light weight, incombustibility, good thermal insulation, sound absorption, energy absorption, and environmental friendliness. It has two types of macrostructure, a closed-cell foam with sealed pores and an open-cell foam with open pores. The open-cell foam has a complex macrostructure consisting of an interconnected network. It can be exploited as a degradable biomaterial and a heat exchanger material. In this paper, open cell Mg alloy foams have been produced by infiltrating molten Mg alloy into porous pre-forms, where granules facilitate porous material. The granules have suitable strength and excellent thermal stability. They are also inexpensive and easily move out from open-cell foamed Mg-Al alloy materials. When the melt casting process used an inert gas, the molten magnesium igniting is resolved easily. The effects of the preheating temperature of the filler particle mould, negative pressure, and granule size on the fluidity of the open cell Mg alloy foam were investigated. With the increased infiltration pressure, preheat temperature and granule sizes during casting process, the molten AZ31 alloy was high fluidity. The optimum casting temperature, preheating temperature of the filler particle mould, and negative pressure were $750^{\circ}C$, $400-500^{\circ}C$, and 5000-6000 Pa, respectively, At these conditions the AZ31 alloy had good fluidity and castability with the longest infiltration length, fewer defects, and a uniform pore structure.

• Knowledge Management Research
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• v.14 no.3
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• pp.37-54
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• 2013

Technology standards have gained importance as global market becomes more competitive. Since a technology acknowledged as a standard brings significant benefits to the developer firm, firms in the IT industry tend to pursue standardization for the technology, being it proprietary or open. However, the paths or strategic implications are seldom discussed in academia. Therefore, our study uses iPhone of Apple, one of the proprietary standards successes, to further understand corporate strategies over two standard choices. Our case study suggests that iPhone's entry timing was optimal for creating a new mobile environment. Design excellence and user-friendly interface increased networking effects and switching costs among consumers. Apple developed independent mobile operating system (iOS) through improvement on the existing operating system. During the process, Apple chose proprietary standard and, by installing the same UX on its sibling products such as iPod Touch or iPad, overcame the subsequent problems that might arise from the limited use of iOS. Based on the capability of concurrently developing both hardware and software, Apple connected operating system, machine, and contents, which deems to contribute to its proprietary standards success. We argue that this strategy should be considered for firms which plan proprietary standard strategy.