• Korean Chemical Engineering Research
• /
• v.58 no.3
• /
• pp.493-497
• /
• 2020

Hazardous area classification is designed to prevent chemical plant explosions in advance. Generally, the duration of the explosive atmosphere is used for zone type classification. Herein, IEC code, a quantitative zone type classification methodology, was used to achieve Zone 2 NE, which indicates a practical non-explosion condition. This study analyzed the operating pressure of a vessel handling propane to achieve Zone 2 NE by applying the IEC code via MATLAB. The resulting zone type and hazardous area grades were compared with the results from other design standards, namely API and EI codes. According to the IEC code, the operating pressure of vessels handling propane should be between 101325-116560.59 Pa. In contrast, the zone type classification criteria used by API and EI codes are abstract. Therefore, since these codes could interpret excessively explosive atmospheres, care is required while using them for hazardous area classification design.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.21 no.3
• /
• pp.1-8
• /
• 2013

An application of adaptive flight controller is required for the non-linear and high uncertain system that configuration of tiltrotor aircraft is dramatically changed from rotary wing mode to fixed wing mode. In this paper, the applicable adaptive controller for the tiltrotor aircraft was designed using Neural Networks and DMI (Dynamic Model Inversion). The performance of the SCAS (Stability and Control Augmentation System) was simulated against manned military specification, using the fullscale model of 'Smart UAV(Unmanned Aerial Vehicle)' developed by Korea Aerospace Research Institute. And Neural Networks based adaptive controller was verified through its whole operating envelope using the established HQ (Handling Quality) criteria.

• Journal of the Korea Society for Simulation
• /
• v.10 no.3
• /
• pp.71-82
• /
• 2001

Considering material handling delay which occurs between storage and processing stations, we propose an algorithm to estimate the required storage capacity, i.e., number of aisles and number of openings in vertical and horizontal directions in each aisle, of an automated storage/retrieval(AS/R) system. Due to the random nature of storage and retrieval requests, proportion of single and dual commands is not known in advance. Two design criteria, maximum permissible overflow probability and maximum allowable storage/retrieval(S/R) machine utilization, are used to compute the storage capacity. Most of studies assume that storage capacity of AS/R systems is given, although it is a very important decision variable in the design phase. Therefore, the proposed model can be effectively used in the design phase of new AS/R systems.

• Proceedings of the Safety Management and Science Conference
• /
• 2010.04a
• /
• pp.181-188
• /
• 2010

The research presents the implementation and improvement strategies of scientific methodologies and techniques in the audit criteria of KS certification. The paper discusses the establishment of management strategy and quality policy by the alignment of BSC or policy deployment, the effective handling methodologies of control plan based on SPC, and the traceability of calibration uncertainty and MSA, etc.

• Journal of Navigation and Port Research
• /
• v.40 no.5
• /
• pp.291-297
• /
• 2016

Ulsan Port is the main port for handling liquid cargo because of natural environmental conditions and the distribution of port infrastructures in Korea. Damage to both liquid cargo vessels and the port structure caused by maritime accidents could have a serious impact on property and human lives as well as the marine environment. For safe navigation, the parties concerned should ensure the suitability of various design criteria at the harbor design stage. In this paper we analyze and compare various domestic and international harbor design criteria, and then apply each criteria to Ulsan port to evaluate its overall safety. Additionally, this paper specifies certain precautions in terms of reviewing a ship's safety for each channel at Ulsan Port, and suggests possible improvements to optimize channel design.

• Industrial Engineering and Management Systems
• /
• v.12 no.4
• /
• pp.389-405
• /
• 2013

A facility layout design (FLD) problem can be generally introduced as assignment of facilities (departments) to a site such that a set of criteria are satisfied or some objectives are minimized (maximized). Hence, it can be considered as a multi-criteria problem due to the presence of qualitative criteria such as maintenance or flexibility and quantitative criteria such as the total cost of handling material. The VIKOR method was developed to solve multiple criteria decision making problems with conflicting and non-commensurable (different units) criteria, assuming that compromising is acceptable for conflict resolution, the decision maker wants a solution that is the closest to the ideal, and the alternatives are evaluated according to all established criteria. This paper proposes a hierarchical analytic hierarchy process (AHP) and VIKOR approach to solve the FLD problem. A computer-aided layout-planning tool is adopted to generate the facility layout problems, as well as their quantitative data. The qualitative performance measures are weighted by AHP. VIKOR is then used to solve the FLD problem. Finally, the proposed integrated procedure is applied to three real-time examples.

• Safety and Health at Work
• /
• v.8 no.1
• /
• pp.11-18
• /
• 2017

The purpose of this review is to name and describe the important factors of musculoskeletal strain originating from pushing and pulling tasks such as cart handling that are commonly found in industrial contexts. A literature database search was performed using the research platform Web of Science. For a study to be included in this review differences in measured or calculated strain had to be investigated with regard to: (1) cart weight/ load; (2) handle position and design; (3) exerted forces; (4) handling task (push and pull); or (5) task experience. Thirteen studies met the inclusion criteria and proved to be of adequate methodological quality by the standards of the Alberta Heritage Foundation for Medical Research. External load or cart weight proved to be the most influential factor of strain. The ideal handle positions ranged from hip to shoulder height and were dependent on the strain factor that was focused on as well as the handling task. Furthermore, task experience and subsequently handling technique were also key to reducing strain. Workplace settings that regularly involve pushing and pulling should be checked for potential improvements with regards to lower weight of the loaded handling device, handle design, and good practice guidelines to further reduce musculoskeletal disease prevalence.

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

• Journal of the Ergonomics Society of Korea
• /
• v.29 no.1
• /
• pp.145-153
• /
• 2010

Activity of lifting has been a major issue in many research area related in manual materials handling tasks. However, the opposite activity of lifting, lowering, has received much less attention. It is known that 52% of all box-handling tasks were lowering in nature. The difference in stress between lifting and lowering activity is not well understood. A simple assumption that these two activities are very similar has been established and widely used. However, this simple assumption may be questionable. The objective of this study was to compare a lifting activity and a lowering activity based on the three different ergonomic approaches; (1) biomechanical, (2) physiological, (3) psychophysical approach. It was found that the stress of lowering activity was from 65% to 93%, from 87% to 97%, and from 87% to 96% according to the biomechanical, physiological, and psychophysical point of view, respectively. It is concluded from the result of this study that the stress of lowering activity is lower than that of the lifting activity. The maximum compressive force on the lumbro-sacral joint (L5/S1) was 158% and 108% respectively, for lifting and lowering activity of which the work load is the 58% of Action Limit. It is suggested that the NIOSH AL and RWL and biomechanical criteria should be reconsidered especially for the low frequency of lifting activities.

• Journal of the Korean Institute of Navigation
• /
• v.7 no.2
• /
• pp.65-113
• /
• 1983

A lot of studies of ship's economy are on the traditional fields such asreducing propulsion resistance, raising cargo handling rates and lessening building consts, but there are few researches on the merchant ship's economy concerning their deadweights and speeds according to shipping companies managerial cercumstances. Contrary to the contemporary trend that "the bigger, the better, if the cargo handling rate could increased sufficiently to hold down port time to that rate of smmaler vessels", this paper demonstrates the existence of certain limits in ship's size and speed according to the coditions of the freight rates, voyage distances, cargo handing rates, prices of fuel oil, interst rates etc. Fom the curves of criteria contour for various ship's deadweights and speeds which are depicted from the gird search method, one can get the costs and the yearly profit rates under the conditiions of large volume with long term contracts for the transportation of bulk cargoes. In estimating ship's transportation economy, the auther takes the position that the profit rate method is properer than the cost method, and introduces the calculation table of the voyage profit rate index. The use of the criteria contours will be of help to ship owners in determining the size and speed of the ship which will be built or purchased and serve in a certain trade route.