• Title/Summary/Keyword: LAS

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Near Infrared Spectroscopy of LAS (linear alkyl benzene sulfonate) (근적외선 분광분석법을 이용한 LAS (linear alkyl benzene sulfonate)의 정량분석법)

  • 조창희;최병기;김효진
    • Environmental Analysis Health and Toxicology
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    • v.15 no.1_2
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    • pp.39-43
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    • 2000
  • Linear alkyl sulfonates (LAS) constitute a large fraction of the surfactants used in cleaning processes in households, trade and industry Despite the industrial significance and the possible environmental impact of these compounds, the fast and inexpensive determination of LAS concentrations is still a difficult task. In this study, near infrared (NIR) spectroscopy which is a rapid spectroscopic analysis method compared with a traditional analytical method for the measurement of LAS concentration such as HPLC, GC and standard wet chemistry method. NIR spectra of LAS between 0.313 and 25.0% (w/v) in water were utilized to develop a calibration model. The best results (R = 0.998, SEP = 0.244% (w/v)) obtained by using partial least-squares regression with spectral data treatment and 2nd derivatization were comparable to the results (SEC = 0.186% (w/v), SEP = 0.206% (w/v)) obtained by using multiple linear least-squares regression (MLR). However, models based on derivative spectra have no significant advantage with MLR.

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Indicator Elimination for Locally Adaptive Scheme Using Data Hiding Technique

  • Chang, Hon-Hang;Chou, Yung-Chen;Shih, Timothy K.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4624-4642
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    • 2014
  • Image compression is a popular research issue that focuses on the problems of reducing the size of multimedia files. Vector Quantization (VQ) is a well-known lossy compression method which can significantly reduce the size of a digital image while maintaining acceptable visual quality. A locally adaptive scheme (LAS) was proposed to improve the compression rate of VQ in 1997. However, a LAS needs extra indicators to indicate the sources, consequently the compression rate of LAS will be affected. In this paper, we propose a novel method to eliminate the LAS indicators and so improve the compression rate. The proposed method uses the concept of data hiding to conceal the indicators, thus further improving the compression rate of LAS. From experimental results, it is clearly demonstrated that the proposed method can actually eliminate the extra indicators while successfully improving the compression rate of the LAS.

Phase Formation and Rheological Characteristics of LAS Derived from the Monophasic Sol-Gel Route (Sol-Gel 반응으로 유도된 LAS의 상 생성과 점성 특성)

  • 장현명;김광수;정창주
    • Journal of the Korean Ceramic Society
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    • v.28 no.5
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    • pp.365-372
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    • 1991
  • LAS (lithium aluminosilicate) sol was synthesized using the hydrolysis-condensation reaction of TEOS, chelated Al(OBus)3 and Li-salt with H2O in alcohol (EtOH+2-Propanol) medium. Effects of important reaction parameters on the properties of sol and gel-derived LAS were examined. The crystallization of the sol-gel derived LAS with ${\beta}$-spodumene composition began at ∼600$^{\circ}C$, and a series of polymorphic transformations occurred as temperature was increased to 1100$^{\circ}C$: amorphous LAS\longrightarrowhexagonal LiAl(SiO3)2\longrightarrow${\beta}$-spodumene. Lowering Li content in the gel enhanced densification and retarded the crystallization significantly. Optimum reaction conditions of LAS sol formation for thin coating applications were derived from rheological measurements, and these can be summarized as: H2O/total alkoxides molar ratio=4, pH=∼2.5, and aging time of ∼250h.

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The Emergence and Development of the Lamaist Gateway of $Lokap\bar{a}las$ during the $Jos\breve{o}n$ Dynasty - Some problems on the orientation of the Gateway of Lokapala and on the allocation of the Four Guardian Kings - (조선시대 라마계 천왕문의 수용 및 전개에 대하여 -천왕문의 배치와 사천왕 배열에 관한 문제-)

  • Yi, Dae-Am
    • Journal of architectural history
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    • v.16 no.6
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    • pp.47-66
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    • 2007
  • $Lokap{\bar{a}}las$ are understood as the deities of four directions in Buddhism: $Dhrtar{\bar{a}}stra$ in the East, $Vir{\bar{u}}dhaka$ in the South, $Vir{\bar{u}}p{\bar{a}}ksa$ in the West and $Vai{\acute{s}}ravana$ in the North respectively. Their common name is, therefore, called as the "Four Guardian Kings", whose function is to prevent demonic forces from entering into its sacred world. Although the position of $Lokap{\bar{a}}las$ is to the lowest level in the hierarchy of the minor deities in Buddhism, the cult of $Lokap{\bar{a}}las$ was widely spread and prominent in the countries of Northern Buddhism. It played a significant role in terms of the state-protecting Buddhism, on behalf of it's esoteric and magic power. More than 20 Gateways of the $Lokap{\bar{a}}las$ and $Lokap{\bar{a}}la$ statues were still well preserved in Korea, and they were believed to be constructed after the Japanese attack in 1592. After war, monks had concentrated on restoring ruined temples and building many new Gateways of the Four Guardian Kings over the Korean peninsular. Under such circumstances, even though the $Lokap{\bar{a}}las$ played a significant role as the subject of cult in Korean Buddhism. they might have a small chance to be taught traditional Lama iconography exactly. The purpose of this essay is to examine the relation of orientation of the Gate way of $Lokap{\bar{a}}las$ and allocation of each Kings inside the gate.

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Densification and Crystallization Characteristics of LAS Gels Prepared by the Hydrolysis-Condensation Reaction and the Mixed Colloidal Processing Route (가수분해-축합반응 및 콜로이드 혼합법으로 유도된 LAS gel의 치밀화와 결정화 특성)

  • 김광수;장현명;정창주
    • Journal of the Korean Ceramic Society
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    • v.28 no.11
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    • pp.865-872
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    • 1991
  • LAS (lithium aluminosilicate) sol was synthesized using the hydrolysis-condensation reaction of TEOS, chelated Al(OBus)3 and LiNO3 with H2O in alcohol (ethanol+2-propanol) medium. Lowering Li content by a factor of 1/2 significantly enhanced densification and retarded the crystallization of LAS gel by ~30$0^{\circ}C$. Dense LAS specimen with essentially pore-free microstructure was obtained by sintering the sol-gel derived gel at 80$0^{\circ}C$ for 4 h and annealing at 120$0^{\circ}C$ for 2 h. Similary, a mixed colloidal processing was attempted as a convenient, alternative route for the fabrication of dense LAS sintered body. The $\beta$-spodumene seeding (~0.8 ${\mu}{\textrm}{m}$) in the sol-gel derived LAS modified the sequence of phase transformations and lowered the temperature of crystallization by ~12$0^{\circ}C$. Combining the epitaxial seeding with the sol-gel process, we could lower the crystallization temperature to the sintering temperature range (~80$0^{\circ}C$) and, demonstrate a possibility of making the viscous sintering/crystallization as a continuous as a continuous unit process.

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Lower Extremity Movement Patterns and Variability in Adolescent Athletes with Lateral Ankle Sprain History during Drop Vertical Jump (가쪽 발목 염좌 경험이 있는 유소년 운동선수의 착지 점프 시 하지 움직임 패턴 및 가변성)

  • Sunghe Ha;Inje Lee;Joo-Nyeon Kim
    • Korean Journal of Applied Biomechanics
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    • v.33 no.3
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    • pp.85-93
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    • 2023
  • Objective: This study examined differences in joint kinematics and movement variability of lower extremity between adolescent athletes with and without lateral ankle sprain (LAS) history during drop vertical jump. Method: Fourteen adolescent athletes with LAS history and 14 controls participated in this study. The independent variable was group while dependent variables were 3D joint kinematics and movement variability of hip, knee, and ankle joint. Ensemble curve analyses were conducted to identify differences in movement strategies between two groups. Results: The LAS group showed that greater eversion during jump phase compared with the control group. Additionally, less movement variability was found in the LAS group during the pre-landing and jump phases in ankle and hip joints compared with the control group. Conclusion: The LAS group may adapt the environmental constraints by reducing the movement variability in ankle and hip joints. However, training programs focusing on recovery of ankle function should be emphasized after LAS because excessive pronation for prevention of LAS during the jump phase may result in reduced performance.

Formas Pronominales de Tratamiento en la Enseñanza del Español como Lengua Extranjera (스페인어 교육과 대명사 호칭어)

  • Kim, Uh-Sung
    • Iberoamérica
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    • v.11 no.2
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    • pp.65-89
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    • 2009
  • El presente trabajo tiene como objetivo proporcionar una explicación simplificada pero suficiente sobre el uso de las formas pronominales de tratamiento en los países de habla española, y hacer una propuesta para la enseñanza de los pronombres de tratamiento en la enseñanza del español en Corea. En la actualidad, en el mundo hispánico existen varios sistemas de tratamiento pronominal. La distribución dialectal de sus formas es bastante complicada. En la norma de España se usa el tú para el trato informal en oposición con el usted para el trato formal. Mientras tanto, en Hispanoamérica se usan el tú y el vos para el trato informal, y el usted para el trato formal. Sin embargo, la mayoría de las gramáticas didácticas y manuales no ofrece una explicación suficiente en cuanto a las diferencias de las formas y el uso de los pronombres de tratamiento. En Corea, en la mayoría de las clases de español se enseñan sólo la norma de España, que es minoitaria entre la comunidad global de hispanohablantes. Eso no les permitiría a los estudiantes tener una interacción exitosa con personas que dominen otras normas del tratamiento pronominal. Para que los alumnos tengan una competencia comunicativa que sea lo más universalmente válida, es necesario ofrecer una perspectiva de los fenómenos lingüísticos y culturales que toman en cuenta las variedades del sistema del tratamiento pronominal que se usan hoy en día en el dominio hispánico. Por último, los intereses y el nivel de los alumnos son variables que determinan qué o cuánto hacer en la enseñanza de las formas pronominales de tratamiento.

Differences in Static Lower Extremity Alignment according to the History of Lateral Ankle Sprain: Efficacy and Limitation of Static Lower Limb Alignment Measurement as a Predictor of Lateral Ankle Sprain (외측 발목 염좌 병력에 따른 정적 하지 정렬 차이: 외측 발목 염좌의 예측인자로서 정적 하지 정렬 검사의 효용성과 한계점)

  • Jeon, Hyung Gyu;Ha, Sunghe;Lee, Inje;Kang, Tae Kyu;Kim, Eun Sung;Lee, Sae Yong
    • Korean Journal of Applied Biomechanics
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    • v.31 no.1
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    • pp.1-15
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    • 2021
  • Objective: The aim of this study was to investigate 1) the difference in static lower extremity alignment (SLEA) according to a history of lateral ankle sprain (LAS), 2) to identify SLEA factors affecting LAS, and 3) to present the cut-off value and 4) the usefulness and limitations of the SLEA measurement. Method: This case-control study recruited 88 men (age: 27.78±4.69 yrs) and 39 women (age: 24.62±4.20 yrs) subjects with and without LAS. SLEA measurement protocol included Q angle, tibiofemoral angle, genu recurvatum, rear foot (RF) angle, tibal varum and torsion, navicular drop, ankle dorsiflexion range of motion (DF ROM). Independent t-test, logistic regression and receiver operating characteristic (ROC) curve were used for statistical analysis. Results: Men with a history of LAS had significantly smaller Q angles both in standing and in supine position, while women with a history of LAS had significantly greater DF ROM in non-weight bearing (NWB; p < 0.05). Logistic regression model suggests tibial varum (OR = 0.779, p = 0.021) and WB DF ROM (OR = 1.067, p = 0.045) were associated with LAS in men. In case of women, there were no significant SLEA factors for LAS, however, ROC curve analysis revealed standing RF angle (AUC = 0.647, p = 0.028) and NWB DF ROM (AUC = 0.648, p = 0.026) could be affecting factors for LAS. Conclusion: There are differences in SLEA according to the history of LAS, furthermore, the identified items were different by sex. In case of men, tibial varum and WB DF ROM affect LAS occurrence. Standing RF angle and NWB DF ROM of women could be a predictor for LAS. However, since the sensitivity and specificity in most of the SLEA measurements are low, kinematic in dynamic tasks should be considered together for a more accurate evaluation of LAS risk.

A Study on the Mg-doped LAS Ceramics Using Metal Alkoxide (금속 알콕사이드를 이용한 Mg-doped LAS계 내열세라믹스의 제조 및 소결에 관한 연구)

  • 김영배;김형태;이응상
    • Journal of the Korean Ceramic Society
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    • v.32 no.1
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    • pp.45-50
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    • 1995
  • In order to densify LAS(Lithuim Aluminosilicate)system compounds, we used metal alkoxides as precursors. Also Mg was added by sol-gel method using metal alkoxides to the LAS system for improving the sinterability, thermal and mechanical properties. The result was that the synthesizing temperature was lowered about 10$0^{\circ}C$, the sintering temperature was lowered by over 10$0^{\circ}C$ and MOR of samples from metal alkoxides was two times larger than that of sample form oxide.

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The Surface Activities of Surfactant Mixtures (혼합 개면활성제의 개면활성에 관한 연구)

  • 정혜원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.3
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    • pp.348-354
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    • 1994
  • The changes of surface activities in the aquaous solutions of mixed surfactants composed of linear sodium dodecylbenznesulfoate (LAS), polyoxyethylene nonyl phenylether (PE, EO=10) and polyethylene glycol monolauryl ether (LE, EO=25) have been studied. Addition of nonionic surfactants to LAS reduces the surface tension, especially at the lower concentration than cmc. The interfacial tension of olive oil/LAS was lower than the other surfactant solutions. The removal of triolein from cotton fabrics by nonionic surfactants and mixtures is higher than by LAS. The addition of NaCI to surfactant solutions even though reduces surface tension smaller but enthances oil removal more than that of $CaCl_2$.

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