• Journal of Advanced Marine Engineering and Technology
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• v.26 no.3
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• pp.382-388
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• 2002

Dissolved silica is one of fatal components at a boiler facility Therefore, a dissolved silica measurement system should be equipped for managing efficiently the boiler facility. Most of silica measurement systems are composed of a sensor module of single-beam type structure, and silica density is measured with a infrared spectrometry using the Lambert-beer method. However, such a system occurs measuring error of large range and inconsistency of a light source, because of measuring a standard sample and a measuring sample alternatively. This paper introduces a method that the sensor module has a split-beam type structure and a tungsten lamp. The proposed system can measure silica density quickly and precisely more than those composing of a single-beam type structure, because of measuring and comparing with two samples at a same time. And examination results are shown to compare efficiencies of the system and existing commercial products, and for an ammonia influence.

• Journal of Korea Foundry Society
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• v.28 no.4
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• pp.190-194
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• 2008

Thin-walled die casting of aluminum notebook computer housing with less than 1mm thickness was investigated by using computational solidification simulation and actual casting experiment. Three different types of gate design, finger, tangential and split type, were used and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt flowed into the thin-wall cavity uniformly and split type gating system was preferable gating design than tangential type at the point of view of soundness of casting and distortion generated after solidification. Also, solidification simulation agreed well with the actual die-casting and the casting showed no casting defect and distortion.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.771-780
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• 2007

In recent studies, various types of multi mode electric variable transmissions of hybrid electric vehicles have been proposed. Multi mode electric variable transmission consists of two or more different types of planetary gear hybrid powertrain system(PGHP), which can change its power flow type by means of clutches for improving transmission efficiencies. Generally, the power flows can be classified into three different types such as input split, output split and compound split. In this study, we analyzed power transmission characteristics of the possible six input split systems, and found the suitable system for single or multi mode hybrid powertrain. The input split system used in PRIUS is identified as a best system for single mode, and moreover we identified some suitable systems for dual mode.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.4
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• pp.96-103
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• 2005

We designed the compound CVT(Continuously Variable Transmissions) by combining power circulation mode and power split mode, which have been proposed for connecting 2K-H I differential gear to the V- belt type CVU(Continuously Variable Unit), as an input coupled type. With the designed compound CVT, we carried out theoretical analysis and performance experiments for efficiency, speed ratio, power flow, and power transmission ratio. We proved that the compound CVT had a better performance than either of the power circulation mode or power split mode.

• Proceedings of the Korean Fiber Society Conference
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• 2000.04a
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• pp.209-212
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• 2000

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.4
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• pp.359-367
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• 2012

In this paper, the input split type series-parallel hybrid electric vehicle (SPHEV) is established and the interpretation of the dynamic characteristics in four kinds of HEV modes, such as electric vehicle mode, engine mode, hybrid mode, and regeneration mode, is described. For this research, the forward-facing approach simulation method is chosen, which is useful for vehicle dynamic analysis. The rating of each powertrain component is designed based on energy-based concept and electrical peaking hybrid (ELPH) method. Finally, the designed powertrain is evaluated with the developed PSiM simulator and simulation results are shown.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.168-173
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• 2004

This article describes the design of a hydraulic system for a power split type continuously variable transmission (CVT). The CVT considered here, is composed of planetary gears, clutches, and a torque converter which is mainly used for the realization of CVT function. Similar to automatic transmissions, the hydraulic system of CVT is designed for supplying hydraulic flows and pressures to each component of CVT, in order to activate the clutch engagements and torque converter operation, and to cool the drivetrain. By using the mathematical models of drivetrain, a simulation program was developed to investigate the power performance of CVT equipped vehicle and the operating conditions of each component of CVT. And the design parameters of the hydraulic system and clutches were calculated using the operating conditions and power requirements which obtained from the simulation results. Finally the hydraulic circuit design of prototyped valve body is presented based on the numerical results of this analysis.

• Journal of Mechanical Science and Technology
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• v.20 no.6
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• pp.770-781
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• 2006

This paper defined design constraints for the compound CVTs (continuously variable trans-missions) by combining power-circulation-mode CVTs and power-split-mode CVTs, which were proposed for connecting 2K-H I-type differential gear to V-belt-type CVU (Continuously Variable Unit). The design constraints are the necessary and sufficient conditions to avoid geometrical interferences among elements in the compound CVTs, and to guarantee smooth assembly between the power-circulation-mode CVT and power-split-mode CVT Two com-pound CVTs were designed and manufactured in accordance with the design constraints. With these compound CVTs, theoretical analysis and performance experiments were conducted. The results showed that the design constraints were valid and effective design method, and that the designed compound CVTs had the improved performance.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.138-144
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• 2022

To report two cases of type 1.5 split cord malformation (SCM), a subtype of SCM with combined characteristics of types I and II and to review the relevant literature and propose a new possible pathogenetic theory for type 1.5 SCM. A 52-year-old woman had hemicords within a single dural sac with a dorsal bony septum at the L5 level. A 9-year-old boy had hemicords within a single dural sac with a ventral bony septum and fibrous extension at the L3 level. Both patients underwent microsurgical treatments for removing the bony septum, detethering the spinal cord, and sectioning the filum terminale. The surgical procedure revealed an extradural partial bony septum and hemicords within an intact single dural sac in each patient. Both patients were discharged from the hospital without de novo nerve dysfunction. Published cases have validated that types I and II SCM can overlap. We recommend recent type 1.5 SCM as a normative terminology for this overlapping SCM and report two rare cases of this SCM. We propose an associated pathogenesis consisting of uneven distribution and regression to explain type 1.5 SCM. Furthermore, we postulate that the amount of condensing meninx primitiva might determine whether the left bony septum has fibrous extensions to the opposite dura in type 1.5 SCM.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.277-292
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• 2012

The research presents an application of Balanced ANOVA (BANOVA) by utilizing randomized orders for various Split-Plot Designs (SPDs) which include two cell designs, split-plot with one-way HTC (Hard to Control) factor, split-plot with two-way HTC factor, split-split-plot design and nested design. In addition, four MINITAB examples of 2-level split-plot designs based on the number of blocks and the type of whole-plots are presented for practitioners to obtain comprehensive understanding. Furthermore, the geometrical interrelated properties among three typical Designs of Experiments (DOE), such as Factorial Design (FD), Response Surface Design (RSD), and Mixture Design (MD) are discussed in this paper.