• 말소리와 음성과학
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• 제8권4호
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• pp.71-78
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• 2016

The purpose of this study is to investigate the effect of Japanese(L1) on the production of Korean accentual phrases(L2). Korean and Japanese have a similar prosodic structure. But different from Korean, Japanese is a pitch accent language. So each word has its own pitch accent. And pitch accents are maintained in the sentence intonation. This difference will have a negative influence on the production of Korean sentence intonation. For this study 4 Korean natives speakers and 10 advanced Japanese learners of Korean participated in the production test. The material analysed constituted 11 Korean sentences, six of which contain formally identical Sino-Korean and Sino-Japanese words. The results show that the initial pitch pattern of Korean accentual phrases was affected by Japanese pitch accent types and this interference was greater for formally identical Sino-Korean and Sino-Japanese words. But besides initial tones of accentual phrase, some positive interference was observed in the internal tonal pattern of accentual phrase. In the phonetic realization, the internal pitch range and initial pitch rising of accentual phrases was greater for Japanese learners of Korean than native speakers of Korean.

• 한국위성정보통신학회논문지
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• 제8권4호
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• pp.58-63
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• 2013

무선통신 시스템 간의 주파수 간섭은 시스템의 성능을 감소시키거나 운용을 제한할 수 있으므로 신규 시스템의 도입 이전에 기존 시스템들과의 주파수 양립성 평가가 반드시 수행되어야 한다. 본 논문에서는 1.6 GHz 대역 무선항행위성업무 시스템의 인접대역에서 신규 이동통신업무 시스템을 운용하기 위한 양립성 평가 알고리즘을 제시하였으며, 동일 지역 내에서 운용되는 이동통신업무시스템과 무선항행위성업무 시스템 상호 간의 최소결합손실 (Minimum Coupling Loss; MCL) 분석 결과로부터 두 시스템 간의 주파수 공유를 위한 조건을 도출하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4050-4067
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• 2014

In wireless sensor networks, link scheduling is a fundamental problem related to throughput capacity and delay. For a given set of communication requests $L=\{l_1,l_2,{\cdots},l_n\}$, the MLS (maximum link scheduling) problem aims to find the largest possible subset S of Lsuch that the links in S can be scheduled simultaneously. Most of the existing results did not consider bidirectional transmission setting, which is more realistic in wireless sensor networks. In this paper, under physical interference model SINR (signal-to-noise-plus-interference-ratio) and bidirectional transmission model, we propose a constant factor approximation algorithm MLSA (Maximum Link Scheduling Algorithm) for MLS. It is proved that in the same topology setting the capacity under unidirectional transmission model is lager than that under bidirectional transmission model. However, compared with some work under unidirectional transmission model, the capacity of MLSA is improved about 28% to 45%.

• 말소리와 음성과학
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• 제10권4호
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• pp.45-52
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• 2018

This study investigates the effect of Japanese (L1) on the production of the Korean rhythmic structure. Korean and Japanese have typologically different rhythmic structure as a syllable-timed language and mora-timed language, respectively. This rhythmic difference comes from the different phonological properties of the two languages. Due to this difference, Japanese speakers that are learning Korean may produce a different rhythm than native Korean speakers' rhythm. To investigate the influence of the native language's rhythm on the target language, we conducted an acoustic analysis using acoustic metrics such as %V, VarcoV, and VarcoS. Four Korean native speakers and ten advanced Japanese Korean learners participated in a production test. The analyzed material consisted of six Korean sentences that contained various syllable structures. The results showed that KS and JS's rhythms are different in %V as well as in VarcoV. In the case of VarcoS, significant rhythmic difference was observed in the VC and CVC syllable, in which the coda segment is nasal sound. This study allowed us to observe the influence of L1 on production of L2 rhythm.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.233-236
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• 2004

Total impurity analysis of a primary standard solution is one of the essential procedures to determine an accurate concentration of the standard solution by the gravimetry. Bi impurity is determined in Pb standard solutions by inductively coupled plasma mass spectrometry (ICP-MS). The direct nebulization of the Pb standard solution produces a significant amount of the Pb matrix-induced molecular ions which give rise to a serious spectral interference to the Bi determination. In order to avoid the spectral interference from the interferent $^{208}PbH^+$, the hydride generation method is employed for the matrix separation. The Bi hydride vapor is generated by reaction of the sample solution with 1% sodium borohydride solution. The vapor is then directed by argon carrier gas into the ICP after separation from the mixture solution in a liquid-gas separator made of a polytetrafluoroethylene membrane tube. The presence of 1000 ${\mu}$g/mL Pb matrix caused reduction of the bismuthine generation efficiency by about 40%. The standard addition method is used to overcome the chemical interference from the Pb matrix. Optimum conditions are investigated for the hydride-generation ICPMS. The detection limit of this method is 0.5 pg/mL for the sample solutions containing 1000 ${\mu}$g/mL Pb matrix.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.855-859
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• 2000

An application of synergistic solvent extraction for the etermination of trace lithium in sea water has been studied by forming an adduct complex of thenoyltrifluoroacetone (TTA) and trioctylphosphine oxide (TOPO) in a solvent. The interference by major constituents in sea water was eliminated by phosphate precipitation. Ex-perimental conditions such as solution pH, concentrations of TTA and TOPO etc. were optimized in synthetic sea water with similar compositionto its natural counterpart. To eliminate the interference, 1.38g of ammoni-um dihydrogen phosphate and 2.5 mL of ammonia water were added into 100 mL of thediluted solution at $60^{\circ}C$ to form the phosphate precipitates of Ca2+ and Mg2+ ions. After the pH of this filtrate was adjusted to 8.0, 10.0 mL of m-xylene containing 0.1 M TTA and 0.05 M TOPO was added to the solution in a separatory funnel, and the solution was shaken vigorously for 20 minutes. The solvent was separated from the aqueous solution, and 20 uL of m-xylene solution was injected into a gaphite tube to measure the absorbance by GF-AAS. The detection limit was 0.42 ng/mL. Lithium was determined within the range of 146 to 221 ng/mLin Korean coast-al sea waters, and the recoveries in the spiked samples were 94 to 106%.

• 음성과학
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• 제6권
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• pp.7-24
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• 1999

Eleven Korean learners of English took part in an experiment where the production and perception of English /r/ and /l/ in four different word positions was investigated. Overall the subjects made more errors on /l/ in both production and identification tests. The frequency of the subjects' errors was also sensitive to word positions in which the two English liquids occur. Especially the subjects made noticeably fewer errors in intervocalic medial position. It is suggested that the Korean subjects' acquisitional pattern in this particular case of foreign phone learning can be explained more by language particular 'interference' effects rather than 'universal' acoustic arguments such as those given in Dissosway et a1. (1982) and Sheldon and Strange (1982). The results of the experiment also support the minority position among second language educators that in some cases of non-native phone acquisition, learners' production abilities can be developed earlier than their perceptual abilities.

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1529-1532
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• 2005

A simple and cost effective method for separation and preconcentration of Ag(I) at the $10^{-7}\;mol\;L^{-1}$ level in the environmental and mineral samples is present. The method is based on the flotation of Ag(I)-iodide complex as an ion-associate with ferroin in pH of 4 from a large volume of an aqueous solution (500 mL) using nheptane. The floated layer was then dissolved in dimethylsulfoxide (DMSO) for the subsequent spectrophotometric determination. Beer's law was obeyed over a range of 2.0 ${\times}$ $10^{-7}$-4.0 ${\times}$ $10^{-6}$ mol $L^{-1}$ with the apparent molar absorptivity of 2.67 ${\times}$ $10^5$ L $mol^{-1}\;cm^{-1}$. The detection limit (n = 5) was 4 ${\times}$ $10^{-8}$ mol $L^{-1}$, and RSD (n = 5) obtained for 2.0 ${\times}$ $10^{-6}$ mol $L^{-1}$ of Ag(I) was 2.2%. The interference effects of a number of elements was studied and found that only $Hg^{2+}$ at low concentration, and $Pb^{2+}$, $Cd^{2+}$, $Cu^{2+}$, and $Fe^{3+}$ ions at moderately high concentrations were interfered. To overcome on these interference effects, the solution was treated with EDTA at a buffering pH of 4 and passed through a column containing Amberlite IR-120 ionexchanger resin, just before the flotation process. The proposed method was applied to determine of Ag(I) in a synthetic waste water, a photographic washing sample and a geological sample and the results was compared with those obtained from the flame atomic absorption spectrometry. The results were satisfactorily comparable with together, so that the applicability of the proposed method was confirmed in encountering with the real samples.

• 분석과학
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• 제15권6호
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• pp.509-513
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• 2002

본 연구는 우리나라 성인여성의 혈청 내 미량 무기 원소의 농도를 조사하기 위해 중성자 방사화 분석법을 적용하였다. 혈청시료중의 나트륨과 염소의 높은 농도가 분석에 제헌을 주었으며 이들의 간섭을 최소화시킨 분석조건에서 Br, Ca, Cl, Co, Cr, Cs, Fe, K, Na, Rb, Se, Zn 와 같은 12종 원소의 분석이 가능하였다. 63명의 성인여성으로부터 채취한 혈청시료를 분석시료를 분석하여 각 원소의 농도수준과 범위 등을 결정하였으며 미국표준연구소의 표준물질들을 혈청시료와 동시에 분석하여 분석품질관리에 사용하였다. 혈청시료중의 무기질원소들의 평균값은 Na 과 Cl은 약 3000 mg/L, Ca은 약 100 mg/L, K은 200 mg/L, Br, Se 및 Zn은 각각 6.0, 0.1, 1.0 mg/L 등의 농도수준을 보였으며 지금까지 보고된 값과 비교한 결과 큰 차이를 보이지 않았다.

• 음성과학
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• 제12권3호
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• pp.165-173
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• 2005

This paper investigates the influence of the Korean phonology on the production of English words including a stop plus nasal sequence through production experiments with a beginner and an advanced group of Korean English learners. The results of the production experiments show that both the beginner and the advanced group of Korean English learners were under the influence of the Korean phonological rule realizing a stop as a nasal before a nasal when they pronounced a stop plus nasal sequences in English words. The extent of L1 interference was greater in the beginner group than in the advanced group.