• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.127-133
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• 1990

Electronic working length determination is based on the electrical impedence between the root canal and the periodontal ligament Different canal irrigants with different electric conductivity may effect on the accuracy of the electronic mechanism. 0.9% Saline, 2.5% NaOCl and 3% $H_2O_2$ were evaluated either in wet or in dry condition. The results were as follows. 1. The electrical resistance mearured by Impedence Meter (Model #253, portland, USA) were 1 $K{\Omega}$ in 0.9% Saline, 0.1$K{\Omega}$ in 2.5% NaOCl and 48 $K{\Omega}$ in 3% $H_2O_2$. 2. Saline measured -0.57mm from the actual canal length and had significant difference. When dried with paper points, however, it measured -0.25mm demonstrating no statistical difference. 3. 2.5% NaOCl measured -4.07mm in wet and -2.26mm in dry condition and both showed significant difference from the actual canal length. 4. 3% $H_2O_2$ measured +0.02mm in wet and -0.09mm in dry canals and both appeared to be within acceptable range for the electronic working length mechanism.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1541-1548
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• 2001

In this paper, We propose a new Kerberos certification mechanism that improve certification service based on PKINIT that announce in IETF CAT Working Group. Certification between area connected by chain through PKINIT that use X.509 and DS/DNS mutually for service. In order to provide regional services used private key and public key, X.509 of PKINIT is employed on session part and Kerberos's private key on actual authentication part. New mechanism be reduced communication overload doing to simplify certification formality between Client and remote KDC by KDC's certificate use to get ticket in remote sacred ground and remote KDC's reaffirmation process omitted.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.575-581
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• 1993

This paper deals with analysis of articulated robot manipulator used for Arc welding and Material handling. Compared with present robot of which weight holding capacity is 6kg, this robot shows wider and symmetric working range for it's serial type mechanism. The link length is determined to have widest working range by using optimal simulation. To reduce body's weight, small AC servo motor is adopted and driving peak torque exerted at each joint is reduced by using dynamic analysis. So it is possible to reduce body's weight by 40% compared with the same class's robot and get wider working range. And by adopting modular design concept, each axis is designed to be changed easily for user's special need and repair.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.257-266
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• 2014

This study was planned to investigate the effect of the exposure to hazard factors on work environment satisfaction. Existing researches about job satisfaction have focused on the general working conditions, such as working hours, wage, human relationship, job task and so on. Korean Working Conditions Survey was used for this study because that relevant questions were included. The effect of the exposure to hazard factors on work environment satisfaction may be produced by hierarchical regression analysis because of comparison with existing model for work environment satisfaction. The exposure to hazards factors were statistically significant effect on work environment satisfaction after adjusting other confounding variables, such as gender, age, educational level, job security, work hour, work load, work autonomy, social support, etc. This study has some limitation because that KWCS was cross sectional survey. Some researches about the causal effect and its mechanism may be suggested as future study.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1231-1234
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• 2003

A sensor working in outdoor may generate some faulty signal owing to dust and high temperature. This paper describes an intelligent sensor system and controller which has a reconstruction mechanism for faulty signal. The faulty signals are dievided into two types as linear distortion and non linear distortion, respectively. The linear distorted signal is due to dust, and non linear distorted signal is due to physical breakdown of sensor or high temperature. These distorted signal have been reconstructed by the proposed method based on polynomial regression method and principal component analysis approach.. The proposed method has been applied to sun tracking system working in outdoor. For a robust and precision control of sun tracker, a fuzzy controller was also proposed. The fuzzy controller controls the tracker by using the collected sensor signal. The tolerance of the position control is within 1.5 degree. To show the validity of the developed system, some experiments in the field were illustrated.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.57-66
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• 2006

In this paper. proposes Multi_Kerberos certification mechanism that improve certification service of based on PKINIT that made public in IETF CAT Working Group. This paper proposed to a certificate other realm because search position of outside realm through DNS and apply X.509 directory certification system, to get public key from DNS server by chain (CertPath) between realms by certification and key exchange way that provide service between realms applying X.509, DS/DNS of based on PKINIT, in order to provide regional services. This paper proposed mechanism that support efficient certification service about cross realm including key management. the path generation and construction of Certificate using Validation Server, and recovery of Session Key. A Design of Multi_Kerberos system that have effects simplify of certification formality that reduce procedures on communication.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.419-423
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• 2005

In microfactory, loading/unloading mechanism supply the row material to processing machines for manufacturing process such as pressing, cutting, plastic deformation. This mechanism for rnicrofactory is designed as modularity robot. Microfactory system have to be flexible structure for variety product item. For system flexibility, applied mechanisms are developed as moduality. Robot moduality needs the specific characteristics which are different from one of macro, typical robot system. In this paper, we discussed about the modularity robot. and proposed the loading/unloading mechanism for working in microfactory system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12B
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• pp.1051-1059
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• 2003

The key feature of GMPLS is the provision of network resources and the automatic set-up of a path. And the mechanism of protection and restoration of a path is presented when network component fails. This paper suggests CR-LDP Static Detour Mechanism and Dynamic Detour Mechanism. CR-LDP Detours are a mechanism to set up detour paths automatically at every node to protect working path. Hence suggested mechanism performance is compared with existing mechanisms by computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.287-294
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• 2005

It is impossible to replace overnight the present Internet Protocol Version 4(IPv4)-based Internet with Internet Protocol Version 6(IPv6). These two protocols are expected to coexist for a number of years during the transition period. A number of transition mechanisms are proposed by Internet Engineering Task Force(IETF) Next Generation Transition Working Group(Ngtrans WG). However, most of them provide only the mechanism to initiate sessions from hosts within the IPv6 network to those within the IPv4 network, but do not support the initiation from IPv4 hosts to IPv6 ones. In this paper, we propose the IPv4-to-IPv6 Dual Stack Transition Mechanism(4to6 DSTM) which can operate even in the case that IPv4 clients in the IPv4 network initiate connections with dual stack servers in the IPv6 network.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.859-864
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• 2003

This paper presents a design for the novel suspension mechanism of a two-wheeled mobile robot having two casters which is used for indoor environment. Although the indoor environment is less rough than the outdoor one, the fixed caster mechanism has some problems such as causing the robot to be immovable because robot's driving wheels do not have contact with the ground. Therefore, we tried installing a spring-damper suspension mechanism to keep driving capability and to remove pitching phenomenon. However, this suspension mechanism also has the problem, which the robot body inclined by disturbances does not return to the initial position. To deal with above problems and to accomplish desired performances, we designed the Multilayered Suspension Mechanism, which has springs and dampers working partially according to the inclined angle and angular velocity of robot body concerned with pitching. To analyze design, the equations of motion describing their dynamics were developed. Using the equations, simulation results show the improved performance. We confirm the usefulness of the Multilayered Suspension Mechanism by construction and test of a actual prototype.