• Journal of Communications and Networks
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• 제13권3호
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• pp.214-220
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• 2011

This paper attempts to address the effectiveness of physical-layer network coding (PNC) on the throughput improvement for multi-hop multicast in random wireless ad hoc networks (WAHNs). We prove that the per session throughput order with PNC is tightly bounded as ${\Theta}((n\sqrt{m}R(n))^{-1})$ if $m=(R^{-2}(n))$, where n is the total number of nodes, R(n) is the communication range, and m is the number of destinations for each multicast session. We also show that per-session throughput order with PNC is tight bounded as ${\Theta}(n^{-1})$, when $m={\Omega}(R^{-2}(n))$. The results of this paper imply that PNC cannot improve the throughput order of multicast in random WAHNs, which is different from the intuition that PNC may improve the throughput order as it allows simultaneous signal access and combination.

• Journal of Magnetics
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• 제19권2호
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• pp.170-173
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• 2014

The purpose of the present study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with task oriented training, on cortical excitability and upper extremity function recovery in stroke patients. This study was conducted with 31 subjects who were diagnosed as a hemiparesis by stroke. Participants in the experimental (16 members) and control groups (15 members) received rTMS and sham rTMS, respectively, during a 10 minutes session, five days per week for four weeks, followed by task oriented training during a 30 minutes session, five days per week for four weeks. Motor cortex excitability was performed by motor evoked potential and upper limb function was evaluated by motor function test. Both groups showed a significant increment in motor function test and amplitude, latency in motor evoked potential compared to pre-intervention (p < 0.05). A significant difference in post-training gains for the motor function test, amplitude in motor evoked potential was observed between the experimental group and the control group (p < 0.05). The findings of the current study demonstrated that incorporating rTMS in task oriented training may be beneficial in improving the effects of stroke on upper extremity function recovery.

• 대한물리치료과학회지
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• 제9권4호
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• pp.105-112
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• 2002

When any damage or disease occurs, muscular strength and muscular endurance are lowered, and thus, if one is able to be restored from the damage or the disease, appropriate stimulus is required, since the muscles have to restore their proper functions. For such stimulus, the way of exercising and the way using electric stimulus are used in physical therapy. In order to examine the change in muscular strength, muscular endurance and girth of limbs for Biceps brachii, according to the lands of stimulus, in this article a total of 42 healthy male and female adults in their twenties were randomly sampled, and a series of tests were conducted for 6 weeks, for 15 minutes per once, 3 times per week, respectively, dividing them into the group for RUS(Russian Current Stimulation), PRE(Progressive Resistive Exercise) and P+R(RUS + PRE). The findings showed that the change in muscular strength was most significant as for the group for P+R, since it increased from $62.12{\pm}25.30$ before experiment to $95.78{\pm}34.07$ after 6 weeks: the change in muscular endurance was most significant as for the group for P+R, since it increased from $17.57{\pm}6.63$ to $42.86{\pm}10.24$; and the change in the girth of limbs was slightly significant only in the group for P+R, and the remaining two groups showed no significance.

• 한국정보통신학회논문지
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• 제12권9호
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• pp.1666-1674
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• 2008

본 논문에서는 광 가입자망 구성의 여러 형태에 대하여 알아보고, 경제성을 비교분석하여, 어떤 방식의 망 구축이 미래의 광가입자 망으로 가장 경제적인지를 고찰 하였다. 비교분석은 현재 우리나라에서 사용 중인 VDSL2, Ethernet-LAN 그리고 FTTH-R 방식의 세 가지 형태 광 가입자망을 대상으로 하였으며, 각 각의 구성 방식별 회선당 초기투자 비용과 운용 비용 중에서 회선당 고장율 및 소비 전력을 비교분석 하였다. 분석 결과 FTTH-R망이 가장 경제적이었으나 기존에 포설된 동선 가입자망을 고려할 경우 댁내까지 완전한 광케이블 포설로 변환하는 과정의 중간 단계로 동선인 UTP 선로와 혼합하여 사용하는 방식의 중간 단계를 거치는 점진적인 전환이 효율적일 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.349-352
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• 1989

Two Crystal structures of fully dehydrated partially magnesium exchanged zeolite A, stoichiometries of $Mg_{2.5}Na_7-A$ (a = 12.251 (1) ${\AA}$) and $Mg_{1.5}Na_9-A\; (a\;=\;12.214(1)\;{\AA})$ per unit cell, have been determined from the 3-dimensional X-ray diffraction data gathered by counter methods. All structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$. The structures of the dehydrated $Mg_{2.5}Na_7-A$ and $Mg_{1.5}Na_9-A$ were refined to yield the final error indices $R_1$ = 0.042 and $R_2$ = 0.049 with 318 reflections, and $R_1$ = 0.034 and $R_2$ = 0.032 with 252 reflections, respectively, for which I > $3{\sigma}(I)$. Both structures indicate that $Mg^{2+}$ ions are coordinated by three framework oxygens and the angle substended at $Mg^{2+}$ ions, O(3)-Mg(1)-O(3) is ca. $120^{\circ}$, close to the idealized trigonal planar value. $Mg^{2+}$ ions preferentially occupy 6-ring sites and $Na^+$ ions occupy 8-ring sites when total number of cations per unit cell is more than 8.

• 한국수산과학회지
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• 제50권4호
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• pp.437-446
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• 2017

To evaluate the consequences of possible fisheries regulations of anchovy Engraulis japonicus in the Korea Strait, we developed and applied a simulation-based yield-per-recruit (Y/R) model that considered temperature-dependent growth and size-dependent mortality, covering the egg to adult stages. We projected changes in commercial yield and egg production of anchovy with respect to varying biological reference points of 1) the instantaneous fishing mortality, 2) the minimum fork length of anchovy allowed to catch for protecting smaller anchovy ($L_{c,min}$), and 3) the maximum fork length allowed to catch for protecting bigger anchovy ($L_{c,max}$). Our Y/R model showed that the anchovy yield will be maximized at ca. $1.4{\times}10^6tons$ when $L_{c,min}$ ranges between 42-60 mm or at ca. $0.8{\times}10^6tons$ when $L_{c,max}$ ranges from 88-160 mm. At $L_{c,min}=30mm$, the present minimum length of catch, our simulations indicated that the anchovy yield can reach a maximum of $1.2{\times}10^6tons$ in the long-term when the present fishing effort, which annually yields ca. $0.2{\times}10^6tons$ of anchovy, can be increased by a factor of 28. We expect that our simulation-based Y/R model can be applied to other commercially-important small pelagic species in which the traditional Beverton-Holt Y/R model is difficult to apply.

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.426-430
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• 1989

Two crystal structures of iodine sorption complexes of dehydrated partially Co(Ⅱ )-exchanged zeolite A, $Co_{3.5}Na_5-A{\cdot}xI_2$, x = 2.5 and 5.0, have been determined by single crystal X-ray diffraction techniques. Both structures were solved and refined in cubic space group, Pm3m at $21(1)^{\circ}C$. The structures of $Co_{3.5}Na_5-A{\cdot}2.5I_2$(a = 12.173(1) ${\AA}$) and $Co_{3.5}Na_5-A{\cdot}5.0I_2$(a = 12.130(1) ${\AA}$) were refined to the final error indices, $R_1$ = 0.081 and $R_2$ = 0.077 with 261 reflections and $R_1$ = 0.103 and $R_2$ = 0.112 with 225 reflections, respectively, for which I>3${\sigma}$(I). In both structures, 3.5 $Co^{2+}$ ions and 4.5 $Na^+$ ions per unit cell lie at two crystallographically different 6-ring positions. 0.5 $Na^+$ ion lines in an 8-oxygen ring plane. Dehydrated $Co_{3.5}Na_5$-A sorbs 2.5 iodine molecules per unit cell at $70^{\circ}C$ (vapor pressure of $I_2$ is ca. 8.3 torr) within 30 minutes and 5 iodine molecules per unit cell at $80^{\circ}C$ (vapor pressure of $I_2$ is ca. 14.3 torr) within 24 hours. Each iodine molecule makes a close approach, along its axis to framework oxygen atom with I-I-O = $175^{\circ}$.

• Mycobiology
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• 제33권2호
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• pp.109-112
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• 2005

The internal transcribed spacer (ITS) regions including the 3'-end of 18S rRNA gene, 5.8S rRNA gene and the 5'-end of the 28S rRNA gene of Rhizopus spp. were amplified by PCR and analyzed by DNASIS program. Length polymorphism of these region ranged from 564 bp in R. oryzae to 789bp in R. stolonifer. The length and sequence of 5.8S was very conserved with $154{\sim}155\;bp$. The sequence of ITS2 was more variable than that of ITS1. The base substitution rates were ranged from 0 to 0.6069 per site, and higher rate was found in R. stolonifer. In general, transition was usually more frequent than transversion. On the basis of sequencing results, four groups were clustered with value of 61.9% similarity; R. oryzae, R. micros pores, R. homothallicus, and R. stolonifer groups.

• 한국컴퓨터정보학회논문지
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• 제22권2호
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• pp.119-125
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• 2017

In this paper, we propose an approach to evaluating the performance of the national R&D investment in IT(Information Technology) areas in terms of paper, patent and commercialization, and seeking ways to improve the efficiency of the national R&D investment. This is because the government has focused the national R&D investment on IT areas for some time. For that purpose, we gather data on investments, papers, patents, and commercializations for the government sponsored R&D projects in IT areas through National Science & Technology Information Service. From which, we summarize the investment and performance in terms of papers, patents, and commercializations for each IT area, evaluate efficiency per R&D investment for each IT area, and compare the efficiencies among IT areas. Finally, we drive implications for efficiency enhancement and strategic R&D budget allocation for each IT area.

• 한국작물학회지
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• 제45권2호
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• pp.97-102
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• 2000

This experiment was conducted to investigate the changes of harvest index and the relationship between harvest index and yield determination factors by different planting times in the determinate soybean cultivars, Shinpaldal and Danbaeg. Optimum planting were 23 May in 1995 and 1996. Late planting were 13 June in 1995 and 6 June in 1996. Growth period from planting to physiological maturity (R7) was shortened as planting time was delayed in two cultivars due to shortening of reproductive growth period in Shinpaldal, and of vegetative growth period in Danbaeg. Stem weight was distinctly decreased in late planting compared to optimum planting, but seed weight of both cultivars was not different between planting times. Also, seed number per pod and harvest index were significantly increased in late planting and the high correlation was found between two factors. It was suggested that increase of harvest index in late planting would be related with high assimilate use efficiency due to increase of sink capacity. The results of correlation and principal component analysis for yield determination factors showed that main factor on yield determination was pod number per plant at R5 stage associated with dry matter accumulation during early reproductive growth period, seed number per pod and harvest index were the second factor, and one hundred seed weight was the third factor. The result of this experiment indicated that yield determination in soy-bean was dependent mainly on pod number per plant related to dry matter accumulation by early reproductive growth period, and the increase of seed number per pod and harvest index could compensate for yield decrease by shortening of vegetative growth period in late planting. Such result suggests that optimum planting date can be delayed from mid May to early June in improved soybean cultivars in Korea.