• The Journal of Korean Society for School & Community Health Education
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• v.8 no.2
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• pp.79-95
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• 2007

A study was conducted in order to develope HACCP model in school lunch in Korea. Results: 1. Of 22 menus 4(18%) were non heating processes (#1), 2(9%) were food handling by using hands (#2), and 16(73%) were heating processes (#3). Of 279 menus 36(12.9%) belong to process #1, 8(2.9%) to process #2, and 235(84%) to process #3. 2. The critical control points for process #1 were contamination by hands of food handlers, and unsanitary food preparation habits of food handlers. Those for process #2 were improper heating temperature, contaminations by food handlers' hands, and unsanitary food handling habits, and cross contamination by unclean utensils and equipment. 3. Management criteria for the CCPs were conditions of food storage, refrigeration, freezing, food cooking temperature, personal hygiene, washing and sanitization of utensils and equipment. 4. Monitoring criteria for CCPs were observation, temperature checking, inspection of utensils and equipment, and practice of good personal hygiene. 5. Corrective actions were refusal of unsafe products, correction of improper temperature, proper cleaning and sanitization, and proper reheating time and temperature.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3804-3814
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• 2000

This paper presents an efficient implementation of a run-time monitor which checks the satisfaction of the timing constraints of real-time object-oriented programs based on a real-time object model called TMO(Time-triggered Messagedtriggered Object). An execution environment of TMO programs on Windows as, WTMOS(Windows TMO System) has been utilized for the implementation and an experimental application for thermostatic control has been developed to analyze the performance of the run-time monitor. We suggest a methodology for application programmers to specify the target methods with the monitoring conditions and an implementation technique which incurs the small cost by effectively distributing the functions of the monitor into the WTMOS and a TMO object.

• Journal of Korea Foundry Society
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• v.21 no.5
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• pp.290-295
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• 2001

We fabricated test samples containing various shape elements and surface roughness checking points for the jewelry cast master patterns by employing the 3D computer aided design (CAD), selective laser sintering (SLS) rapid prototype (RP) with the DuraForm powders. We varied the alignment angle from $0^{\circ}$ to $10^{\circ}$ at a given layer thickness of 0.08 and 0.1mm, respectively, in RP operation. Dimensions of the shape elements as well as values of surface roughness are characterized by an optical microscope and a contact-scanning profilometer. Surface roughness values of the top and vertical face increased as the alignment angle increased, while the other roughness values and shape elements variation were not depending on the alignment angle. The resolution of the shape realization was enhanced as the layer thickness became smaller. The minimum diameter of the hole, common in jewelry design, was 1.2 mm, and the shrinkage became 12% at the 1.6 mm-diameter hole, Our results implied that we face down the proposed design elements with $0^{\circ}$ alignment angle, and consider the shrinkage effect of each shape element in DuraForm RP jewelry modeling.

• Journal of KIISE:Software and Applications
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• v.31 no.9
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• pp.1218-1225
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• 2004

S/KEY system was proposed to guard against intruder's password replay attack. But S/KEY system has vulnerability that if an attacker derive passphrase from his dictionary file, he can acquire one-time password required for user authentication. In this paper, we propose a correct S/KEY system mixed with EKE to solve the problem. Also, we specify a new S/KEY system with Casper and CSP, verify its secrecy and authentication requirements using FDR model checking tool.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1530-1541
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• 2013

The coexistence and extinction of species are important concepts for biological systems and can be distinguished by an investigation of stability. When determining local stability of nonlinear systems, Lyapunov indirect method based on the Jacobian linearization has been widely employed due to its simplicity. Despite such popularity, it is not applicable to singular systems whose Jacobian has at least one eigenvalue that is equal to zero. In such singular cases, an appropriate Lyapunov function should be sought to determine the stability of systems, which is rather difficult and quite involved. In this paper, we seek for a simple criterion to determine stability of the equilibrium that is located at the boundary of the positive orthant, when one of eigenvalues of the Jacobian is zero. The goal of the paper is to present a generalized condition for the equilibrium to attract all trajectories that starting from initial condition in the positive orthant and near the equilibrium. Unlike the Lyapunov direct method, the proposed method requires just a simple algebraic computation for checking the stability of the critical point. Our approach is applied to various biological systems to show the effectiveness of the proposed method.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.26-35
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• 2003

This study explains the effects of lubricant and surface treatment on hot forging die life. The mechanical and thermal load, and thermal softening which is happened by the high temperature of die, in hot and warm forging, cause die wear, heat checking and plastic deformation, etc. This study is fur the effects of solid lubricants and surface treatment condition for hot forging die. Because cooling effect and low friction are essential to the long life of dies, optimal surface treatment and lubricant are very important to improve die life for hot forging process. The main factors, which affect die hardness and heat transfer, are surface treatments and lubricants, which are related to thermal diffusion coefficient and heat transfer coefficient, etc. For verifying these effects, experiments are performed for hot ring compression test and heat transfer coefficient in various conditions as like different initial billet temperatures and different loads. The effects of lubricant and surface treatment for hot forging die life are explained by their thermal characteristics. The new developed technique in this study for predicting tool life can give more feasible means to improve the tool life in hot forging process.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.5
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• pp.390-396
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• 2014

A study on smart seats for railroad vehicles was conducted using piezoelectric (PZT) sensors. For this purpose, the concept of passenger friendly smart seats was defined, and a PZT sensor was selected as the optimum sensor based on this concept. Using PZT sensors, simulation tests were performed using a sub-scale model railroad vehicle. In these tests, the main functions of the smart seats were extracted and simplified to improve the effectiveness of the simulation tests. Based on the test results, the system for smart seats proposed in this paper was successfully verified using PZT sensors and the dedicated operation software for the system. This paper will contribute to the improvement of services in high-speed rail systems through advances in ticket checking tasks.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.58-62
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• 2008

The purpose of this paper is to establish a standard finite element analysis model of a piston by carrying out three dimensional modeling of a series six-cylindered CNG engine's piston to forecast temperature distribution at stationary state and the following thermal stress and variation, and cross checking it with existing analysis. Also, in order to evaluate the affects of the cooling system to the piston's heat load, the paper analyzed piston's temperature and thermal stress distribution according to the cooling water temperature changes and the following variations. As a result, the maximum temperature was found at the center of the crown in the piston and the maximum thermal stress occurred from the lower part of the piston.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.17-27
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• 2020

The research aims to investigate the impact levels of determinants on the conversion of financial statements from Vietnamese accounting standards (VAS) to International financial reporting standards (IFRS) in the multinational firms in Vietnam. The method of data collection was done through the survey and subjects are accountants in Multinational Firms doing business in Hanoi and ten neighboring provinces. After checking the information on the votes, there are 170 questionnaires with full information for data entry and analysis. We use Cronbach's Alpha, EFA analysis and run regression model to investigate the impact levels of each independent variable on dependent variable of the conversion of VAS financial statements to IFRS. The results show that five determinants including Economic, Politics, Law, Culture, and Conditions for implementation have positive relationships with the conversion of VAS financial statements to IFRS. In particular, Economic determinant is the most strongest. Based on the findings, some recommendations are given for improving the conversion of VAS financial statements to IFRS of multinational firms doing business in the context of Vietnam. The results are considered a useful reference for firms when making financial statements to transparently change the financial statement information and improve the quality of financial statement information.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.4
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• pp.19-26
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• 2019

The study investigates the impact of accrual anomaly on stock return ratio of listed firms in Vietnam. Data were collected from listed firms for the period from 2008 to 2018. To learn about the causes of accrual anomaly in returns and future rate of returns on the Vietnamese stock market, this research is based on accrual analysis of Richardson, Sloan, Soliman, and Tuna (2006) on growth and effective components. We employ GLS regression model for examining the impact of accrual anomaly on stock return ratio and T-test for checking the difference between the lowest and the highest portfolio. The results show that accounting distortion is the main factor impacting the stock return, not growth determinant. Both two determinants of accounting distortion and growth contribute the explanation of the impact of accrual anomaly on profit and future stock return ratio. Experimental evidence confirms an abnormal existence of accrual in the Vietnam stock market. Aggregate accrual is negatively correlated with future operating profit and future stock return. However, after considering the factors contributing to the impact of future profitability and return on stock returns, the study results show that accounting distortion can account for low sustainability of income that is not growth.