Joo-Uk Kim

The optimal dose of remifentanil for intubation during sevoflurane induction without neuromuscular blockade in children

The optimal dose of remifentanil needed to produce successful intubating conditions following inhalation induction of anaesthesia using 5% sevoflurane without the use of neuromuscular blocking drugs, was investigated in 25 children aged 3–10 years. Sixty seconds after inhalation induction of anaesthesia using sevoflurane 5% in 100% oxygen, a predetermined dose of remifentanil was injected over 30 s. The dose of remifentanil was determined using the modified Dixons up‐and‐down method (0.2 μg.kg−1 as a step size). The first patient was tested at 1.0 μg.kg−1 remifentanil. Ninety seconds following the bolus administration of remifentanil, the childs trachea was intubated. The optimal bolus dose of remifentanil required for successful tracheal intubation was 0.56 (0.15) μg.kg−1 in 50% of children during inhalation induction using 5% sevoflurane in the absence of neuromuscular blocking drugs. Using probit analysis, the 95% effective dose (ED95) of remifentanil was 0.75 μg.kg−1 (95% confidence limits 0.63–1.38 μg.kg−1).

The effect of lidocaine on remifentanil-induced cough

This study was performed to investigate the incidence of remifentanil‐induced cough and evaluate the efficacy of lidocaine on its prevention. Five‐hundred patients, aged 18–70 years, were randomly allocated into two groups to receive either lidocaine 0.5 mg.kg−1 or 0.9% normal saline intravenously 1 min before remifentanil administration at a target effect‐site concentration of 4 ng.ml−1. Any episode of cough was classified as coughing and graded as mild (1–2), moderate (3–4) or severe (5 or more). We found that the overall incidence of cough was significantly higher in the saline group (69 patients; 27.6%) than that in the lidocaine group (38 patients; 15.2%) (p < 0.001). The results of logistic regression indicated that age and smoking were associated with remifentanil‐induced cough. This study demonstrated that intravenously administered lidocaine 0.5 mg.kg−1 effectively suppresses remifentanil‐induced cough without possible systemic lidocaine toxicity.

On Slimming down the Functions Room of Light Rail Transit Stations by Utilizing an Enhanced DSM Method

It appears that the rapid advance in technology has allowed to broaden the variety of rail systems technology, thereby fostering new business opportunity in rail industry. The direction of rail systems operations is mainly two fold. In one direction, long distance operations between mega cities are pursued with help of high speed trains under development. In the other case, relatively short distance operations for covering intra-city or suburban area are becoming popular. A good example of the latter case is light rail transit (LRT) systems. Due to the short distance operation, it is thus expected that both the development and operation cost for LRT systems be reduced to some extent. The cost reduction desired in there can be gained by scaling down the sizes of both the trains and stations as compared to those of normal rail systems. However, it is not well known how the LRT stations can be scaled down. The objective of this paper is to study on how to slim down the stations (particularly, the functions room) of LRT systems. To achieve the objective, an approach is studied based on a modified method of design structure matrix (DSM). Specifically, using the enhanced DSM method, an integrated architecture is developed for the functions room, in which equipments are housed to perform the functions of electricity, signaling, and communication for LRT stations. The use of the result indicates that the desired reduction can be obtained with the approach taken in the paper.

On Ensuring the Safety Integrity of the BCT System through Linkage Safety Analysis Techniques and SysML-based Architecture Artifact

Today, it appears that the rapid advances in technology have allowed broadening both the system technology and the business opportunities in the rail industry. Owing to the developments in technology and the industry, and also due to the hearth, the latest high-speed trains and a variety of unattended operations in rail systems are being developed and are operational. In particular, this study covers the existing railway rolling stock and signaling systems that operate in an environment more complex than the concept of localized management, so the introduction of a new signaling system is needed. In addition, developments based on the existing signal system concepts for passenger railways need to minimize human injury. In this study, to participate in the development of new systems in a variety of domains and to provide an integrated common vision methodology as an engineer on the basis of efficient signal system design and safety would like to present the methodology for action. Therefore, each different linkage through the next new domain zone system design: design through to secure the integrity of safety than can secure methodology.

On Enhancing Safety of Train-Centric Train Control System using Model-Based Development

The train control system is a facility to ensure model-based design and safe train operation, and its safety is the most important factor for system introduction, complexity of the design information and traceability etc. Therefore, the model-based design and safety activities regarding the way-side equipment of a train control system is also highlighted. To solve this problem, In this paper, model-based design was carried out first to develop an effective train control system, which is represented by SysML(System Modeling Language). The test scenarios that can take advantage of the design model were created to improve the train safety control system. Case studies of a model-based design of a train-centric train control system were applied to the test scenarios; the results demonstrated its usability. The improved activity over the test highlighted the safety improvement approach, and it is expected to reduce the cost and time in the conceptual design of a future development model-based train control system.

On the Improving Integrity for Verification method of Train-Centric Train Control System Architecture using FMEA Safety Activity

Safety is the most important factor for train control systems. Model-based design and safety activities for way-side equipment in train control systems are important factors. Model-based architecture verification was carried out to develop an effective control system, which is represented by model-based failure mode and effects analysis (FMEA). An architecture verification method was created based on FMEA to take advantage of a design model and improve the train safety control system. Case studies were applied to architecture verification scenarios, and the results demonstrate the usability of the method. The improved method is expected to reduce the cost and time in the conceptual design for future development of model-based verification train control systems.

On the Development of Safety Requirements Based on Functional Analysis of LRT Stations in Concept Development Stage

Abstract For safety-critical systems including railways, there has been a growing need for effective and systematic safety management processes. The outcomes of efforts in this area are international safety standards, such as IEC 61508, 62278, and ISO 26262. One of the principal activities in the safety process is hazard analysis. For this reason,considerable efforts have been directed toward methods of hazard analysis. On the other hand, the hazard analysis methods reported thus far appear to be unclear in terms of their relationship with the system design process. In addition, in some cases, the methods appear to rely heavily on information regarding the hardware and software components, the number of which is increasing. These aspects can become troublesome when design changes are necessary. To improve the situation, in this paper, hazard analysis was carried out using the result of functional analysis early in the concept development stage for a safety-critical system design. Because hazard analysis is carriedout at the system level and the result is then used to develop the safety requirements, improvements can be expectedin terms of the development time and cost when design changes are required due to changes in the requirements.As a case study, the generation of safety requirements for the development of light rail transit stations is presented.

On the Study of Design Guidelines and a Design Case to Enable the Replacement of LRT Stations by Stops

To cope with the increased demand on the intra-city transportation by urban rails, the introduction of the light rail transit (LRT) systems has been expedited in Korea due to the possible reduction of both the development and operation costs from adopting LRT systems. The LRT systems have so far been designed, constructed and operated based on the corresponding law and regulations. It has been conceived that fully complying with the existing guidelines may incur some extra costs on LRT. In addition, the present design of LRT stations seems to require unnecessarily long flow of passengers traffic, particularly for disabled people. In this paper, as an approach to solving the aforementioned issues, an introduction of ‘LRT stops’ has been studied where the stops are similar in concept to bus stops and are intended to replace the stations of a bigger scale in general. Specifically, necessary guidelines for design have been developed by modifying the existing ones to be fit with LRT stops. A design case was also presented to evaluate them. The effective use of the results reported here will provide an opportunity of cost reduction in connection with the construction and operation, and also let people benefit from convenient use of rails, thereby resulting in enhanced transportation welfare.

A Study on the Systems Engineering Process for Effectively Carrying Out LRT Project

Key Words : LRT(Light Rail Transit, ), Systems Engineering(SE, ), Tech경량전철시스템 시스템엔지니어링 nicalProcess( ), Life Cycle( ), Decision Gate(DG, )기술프로세스 생명주기 의사결정게이트초록: 경량전철시스템은버스와지하철의중간정도의수송능력을가진첨단대중교통수단으로주로무인으로운전되며 개사업이조단위의건설비가소요되는대형복합시스템이다 이러한경량전철사업을, 1 .효율적으로수행하기위해서는시스템엔지니어링이매우중요하다 시스템엔지니어링은성공적인시스.템을구현하기위한다분야학문의종합적접근방법과수단으로복잡한시스템을개발 관리하기위해전체적 생명주기적관점에서접근하며 필요한사항을확인하고 해야할일을바르게수행하도(holistic), , ,록안내한다 본논문에서는경량전철사업에서시스템엔지니어링을적용하기위한프로세스를제시한.다. 이를위해국내경량전철사업의시스템엔지니어링특징을분석하고 국내에적합한시스템엔지니,어링프로세스와프로세스의산출물작성을위한템플릿과사례 그리고프로세스를전산으로구현한,사례를제시한다.Abstract : Light rail transit(LRT) is a public transportation and mainly has an automatic driverless operationsystem. LRT project is a large scaled project which a construction cost is tens of billions of won per km.Systems engineering(SE) is an interdisciplinary approach and means to enable realization of successfulsystems. In this paper, we propose the systems engineering processes and their outputs list for the LRTproject. And then, we present template and sample case of process output. We also present a case whichcarried out SE process by SE tool.