• Title/Summary/Keyword: primary phase

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An R package UnifiedDoseFinding for continuous and ordinal outcomes in Phase I dose-finding trials

  • Pan, Haitao;Mu, Rongji;Hsu, Chia-Wei;Zhou, Shouhao
    • Communications for Statistical Applications and Methods
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    • v.29 no.4
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    • pp.421-439
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    • 2022
  • Phase I dose-finding trials are essential in drug development. By finding the maximum tolerated dose (MTD) of a new drug or treatment, a Phase I trial establishes the recommended doses for later-phase testing. The primary toxicity endpoint of interest is often a binary variable, which describes an event of a patient who experiences dose-limiting toxicity. However, there is a growing interest in dose-finding studies regarding non-binary outcomes, defined by either the weighted sum of rates of various toxicity grades or a continuous outcome. Although several novel methods have been proposed in the literature, accessible software is still lacking to implement these methods. This study introduces a newly developed R package, UnifiedDoseFinding, which implements three phase I dose-finding methods with non-binary outcomes (Quasi- and Robust Quasi-CRM designs by Yuan et al. (2007) and Pan et al. (2014), gBOIN design by Mu et al. (2019), and by a method by Ivanova and Kim (2009)). For each of the methods, UnifiedDoseFinding provides corresponding functions that begin with next that determines the dose for the next cohort of patients, select, which selects the MTD defined by the non-binary toxicity endpoint when the trial is completed, and get oc, which obtains the operating characteristics. Three real examples are provided to help practitioners use these methods. The R package UnifiedDoseFinding, which is accessible in R CRAN, provides a user-friendly tool to facilitate the implementation of innovative dose-finding studies with nonbinary outcomes.

Preparation of Bonded Cellulose Tris(3,5-dimethylphenylcarbamate) Chiral Stationary Phases by Using Three Bifunctional Reagents

  • Zhang, Yi Jun;Huang, Mingxian;Zhang, Yuping;Ryoo, Jae Jeong
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2623-2628
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    • 2013
  • Three di-acyl chlolide reagents, adipoyl chloride, terephthaloyl chloride and isophthaloyl chloride, were used as spacer reagents to prepare bonded type of three cellulose (3,5-dimethylphenyl)carbamate (CDMPC) chiral stationary phases (CSPs). The CDMPC CSPs were prepared using these three acid chlorides as spacer agents at the 6-position of the primary hydroxyl group on the glucose unit of cellulose regioselectively. The chiral recognition ability of the prepared CSPs for five racemates was evaluated by normal-phase high-performance liquid chromatography (HPLC) with the following mobile phases: hexane/isopropanol (IPA), hexane/IPA/tetrahydrofuran (THF) and hexane/IPA/chloroform. The result showed that these prepared CSPs can be used in THF and chloroform solutions and the chiral recognition abilities of the CSPs were improved depending on the eluents and chiral samples.

Operating Characteristics in LCLC Resonant Converter with A Low Coupling Transformer. (낮은 커플링 변압기를 갖는 LCLC 공진컨버터 동작특성)

  • Kong Young-Su;Kim Eun-Soo;Lee Hyun-Kwan;Cho Jung-Goo;Kim Yoon-Ho
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.7
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    • pp.343-350
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    • 2005
  • Conventionally, for transferring the primary power to the secondary one, the high frequency series resonant converter has been widely used for the contactless power supply system. However, the high frequency series resonant converter has the disadvantages such as the low efficiency, the high voltage gain characteristics and deviation of the phase angle in the overall load range. To improve this disadvantages, In this paper, the characteristics of the high efficiency and unit voltage gain as well as in-phase are revealed in the proposed three-level LCLC (Inductor-Capacitor- Inductor-Capacitor) resonant converter. The results are verified on the simulation based on the theoretical analysis and the 4kW experimental Prototype.

A Study on recycling of waste concrete for ${PO}_4^{3-}$-P removal contained in livestock wastewater (축산폐수에 함유된 ${PO}_4^{3-}$-P의 제거를 위한 폐콘크리트의 재활용에 관한 연구)

  • 김은호;박진식;성낙창;이영형;신남철;전기일
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.227-231
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    • 1999
  • This study was conducted to investigate the removal characteristics of $PO_4^{3-}-P$ contained in livestock wastewater using waste concrete. With small particle size, increased dosage and temperature of water, $PO_4^{3-}-P$ was well removed by waste concrete.$PO_4^{3-}-P$ was removed by adsorption reaction in low pH of the primary phase, but the crystallization reaction predominated for increasing pH with passed time. As a result of adapting the adsorption isotherm equation, $PO_4^{3-}-P$ removal was more affected by the crystallization reaction than the adsorption reaction. In the SEM micrograph, there was no evident change on the waste concreter surface. Particle size was plate-phase before reaction but appeared a dense form to progress in the crystallization reaction.

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Analysis of two phase thrbulent flow in pipe with suspension of solid particles (고체분말이 부상된 이상난류 관유동의 해석)

  • ;;Chung, Myung Kyoon
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.3
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    • pp.159-169
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    • 1981
  • The mixing length theory is extended to close the momentum queations for two-phase turbulent flow at a first-order closure level. It is assumed that the mass fraction of the particles is of the order of unity, that the particle size is so small that the particles are fully suspended is the primary fluid, and that the relaxation time scale of the particles is of the same order as the time scale of the energy containing eddies so that the suspended particles are responsive to the fluctuating turbulent field. The bulk motion of the particles is treated as a secondary fluid with its own coefficient of momentum transport. The proposed closure is uniformly destributed acress the pipe section. Predicted velocity profiles and the friction factors are in good agreement with avaiable experimental data.

Effects of Flame Temperature on the Characteristics of Flame Synthesized $TiO_{2}$ Nanoparticles (화염온도에 따른 $TiO_{2}$ 나노입자의 결정구조 및 입자크기 변화)

  • Lee, Gyo-Woo;Jurng, Jong-Soo;Bae, Gwi-Nam
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1347-1352
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    • 2004
  • In this work, $TiO_{2}$ nanoparticles were synthesized using a $N_{2}-diluted$ hydrogen coflow diffusion flame. The effect of flame temperature on the crystalline structure and the size of formed nanoparticles was investigated. The maximum centerline temperature of the flame ranged from 1,920K for $H_{2}-only$ flame to 863K for 81% $N_{2}-diluted$ flame. When the temperature was higher than about 1,000K, the particle size was tend to increase due to the agglomeration and sintering among the primary particles. On the other hand, when the temperature was lower than 1,000K, the portion of anatase phase was greater than 80%.

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Effects of Subcooling and Natural Convection on the Melting inside a Horizontal Tube (수평원관내에서 과냉각 및 자연대류가 융해과정에 미치는 영향)

  • 서정세;김찬중;노승탁
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.8
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    • pp.2079-2087
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    • 1993
  • The effects of subcooling and natural convection are studied numerically on the melting process of an initially subcooled phase-change medium filled inside a horizontal circular cylinder. It is postulated that melting continues with the tube wall kept at a constant temperature and with the unmelted solid core fixed. Primary emphasis is placed on the evolution of interface morphology, the local/overall heat transfer rate at the tube wall and at the interface, and the structure of natural convection. The numerical results are mainly presented in terms of the Rayleigh and subcooling numbers. As the degree of subcooling intensifies, the melting rate and the movement of the interface are impeded but the interfaces are of similar shape with the passage of time. The heat transfer characteristics are found to be mostly governed by the formation pattern of natural convection in the liquid phase. Good agreement with available experimental data is found.

A Study of Hydroxyapatite Synthesis by Wet-direct and Hydrothermal Synthesis (습식 및 수열합성법에 의한 Hydroxyapatite의 합성에 관한 연구)

  • 전성용;김홍기;이경희;이병하
    • Journal of the Korean Ceramic Society
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    • v.30 no.3
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    • pp.215-221
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    • 1993
  • The Hydroxyapatite powders were prepared by Wet-direct and Hydrothermal synthesis using Ca(NO3)2.4H2O and (NH4)2.HPO4.Stoichiometric and good cristalline HAp powders were obtained 9$0^{\circ}C$ by wet-direct process. The aspect ratio of HAp powders prepared by hydrothermal synthesis was increased with increasing synthetic temperature. The HAp particles obtained at 20$0^{\circ}C$ for 10hr were needle shaped ultra fine crystals, about 100nm in size. Small amount of TCP was obtained above 80$0^{\circ}C$ after heat-treatment of hydrothermally synthesized HAp but good crystalline HAp phase was maintained up to 120$0^{\circ}C$ as the primary phase.

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Parallel Operation of Single-Phase GTO PWM Converters (단상 GTO PWM CONVERTER의 병렬운전)

  • Lee, Hyeoun-Dong;Lee, Dong-Choon;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.415-418
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    • 1994
  • In this paper, a parallel operation of two single-phase GTO PWM converters is presented. The current ripples on the primary side of the transformer can be much reduced by shifting one modulation period from the other one by a half period. Also, a simple power factor control scheme is presented by which the reactive component of converter input current is controlled. Simulations and experimental results for a laboratory system confirm the validity of the purposed algorithm.

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Uncertainty Analysis in Potential Transformer Calibration Using a High Voltage Capacitance Bridge

  • Jung, Jae-Kap;Lee, Sang-Hwa;Kang, Jeon-Hong;Kwon, Sung-Won;Kim, Myung-Soo
    • Journal of Electrical Engineering and Technology
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    • v.2 no.3
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    • pp.401-407
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    • 2007
  • Precise absolute measurement of the errors in a potential transformer (PT) can be achieved using high voltage capacitance bridge (HVCB) and capacitive divider. The uncertainty in a PT measurement using the HVCB system was evaluated by considering the overall factors affecting during the calibration of a PT. The expanded uncertainties are found to be not more than $30{\times}10^{-6}$ for ratio and $30{\mu}rad$ for phase up to the primary voltage of $V_p=22kV$. For same PTs, the measured errors in KRISS (Korea Research Institute of Standards and Science) using our bridge are well coincide with those in NMIA (National Measurement Institute of Australia) and PTB (Physikalisch-Technische Bundesanstalt) within the corresponding uncertainties.