• Design & Manufacturing
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• v.16 no.4
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• pp.7-16
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• 2022

A helmet is essential for safety when operating personal mobility. However, user's actual helmet wear rate is low due to the inconvenience of wearing and poor ventilation. In this study, a new helmet structure with improved ventilation for personal mobility devices was designed. To design a new structure with improved breathability compared to the existing helmet while satisfying the safety regulations for the helmet, a generative design method was applied to the shock-absorbing liner of the helmet. In addition, other materials were applied to create a structure with improved ventilation while maintaining safety. The generated design result was verified for shock absorption through simulation. As a result of the study, EPS, the current material was replaced with CFRP and Kevlar, and the structure was changed. This design was judged to satisfy safety regulations against impact. The new helmet structure is expected to improve the helmet usability for personal mobility and increase the helmet wear rate of users.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.321-332
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• 2001

In this study, a design program for ventilation requirements of a longitudinal raod tunnel were developed and investigated. The control volume method was applied to calculate the local air velocity and the local concentration distribution of pollutants, CO, $NO_x$, soot along the tunnel for various tunnel ventilation system. This program was validated by comparing with the practical design data for the road tunnel ventilation system. The calculation results were in good agreement with the practical design data.

• Korean Journal of Computational Design and Engineering
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• v.14 no.5
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• pp.330-337
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• 2009

Nowadays a lot of high-tech electronic products such as TVs, monitors and camcorders are being developed. The more functions the electronic devices have, the more heat problems occur. Therefore, most of electronic products have air-ventilation holes to eliminate heat that is generated inside the products. The shapes of ventilation holes are usually complicated since aesthetic appearance of the products is important these days. In order to create those complicated shapes, designers should do time-consuming jobs because most of commercial CAD systems do not provide the functions that create patterns of lofted parts along freeform surfaces. In this research, an automated air-ventilation hole modeling system was proposed. The system generates patterns of lofted objects on freeform surfaces. Standard process to create air-ventilation holes manually was established, and vent-hole types and pattern types were classified into several categories. Designers can create many kinds of vent-holes by combining vent-hole types and pattern types. Users can also utilize user-defined pattern which can give users more flexibility. Developed system was applied to several design examples and the results are presented.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.78-97
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• 2000

Designing the industrial ventilation system is the complex and time-consuming job. It could generate some errors in the design calculations if one uses the hand-calculator or the spreadsheet program. To overcome these difficulties, VSDS(Ventilation System Design Software) had been developed a few years ago. But, it had the difficulty in designing a complex system having many branches because the user can not see the layout of the system on the screen. Another difficulty is that VSDS had been based on the assumption of the standard air condition. VSDS has thus been improved to overcome the shortcomings of the old version of VSDS.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.1
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• pp.61-72
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• 2023

The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.3
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• pp.91-100
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• 1991

Since ventilation in livestock buildings is critical for indoor air quality, the first step in designing environmental control is to determine required ventilation rate. The purpose of the study was to suggest a conceptually new ventilation graph for determining minimum/maximum ventilation rate based on the conservation law of the thermal energy and mass in livestock buildings. PC-based programs coded with PASCAL language, [RVALUE] for overall thermal resistance of composite structural walls/ceilings, [POLYNOM] for coefficients values of animal's sensible heat equation were involved in developing a computer program, [VENTGRPH] for the determination of ventilation rate. It would be useful for design, for such a program would permit the designer to explore various design options and immediately, see the result in terms of its effect on minimum ventilation rates.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.2
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• pp.107-112
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• 2002

There are many combination with the porosity of tipping paper and plug wrap for a design of ventilation rate of cigarette. This study was carried out to determine the effect of a design of permeability of tipping paper and inner or outer of plug wrap on the ventilation rate of cigarette with constant pressure drop in column part and filter part. Our results indicated that the higher the plugwrap porosity, the higher the ventilation rate and the less variable of cigarette in case of mono filter. But, in case of duel filter, the ventilation rate of cigarette was depended on the manufacturing method of filter plug, even though using the same porous plug wrap on inner and outer of filter. We also found that the porosity of outer plug wrap was more effect on the ventilation rate than the porosity of inner plug wrap. As the high porosity of inner plug wrap compared with the porosity of outer plug wrap, the less variable of ventilation rate of cigarette in any combination of the porosity of plug wrap. When we used the higher porous outer plug wrap than inner plug wrap, the ventilation rate of cigarette was high. Also, the higher the inner plug wrap porosity, the less variable of ventilation rate of cigarette.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.35-47
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• 2024

Objectives: Many cases of lung cancer have been reported by school kitchen workers as occupational cancer. Twenty-eight schools in Gyeongsangnam-do Province were selected to evaluate the effect of improved kitchen ventilation systems. Ventilation characteristics before and after renovation were compared and design techniques were identified. Methods: In the design stage for kitchen ventilation systems, expert intervention was used to improve the designs. Ventilation characteristics and air quality were evaluated before and after the renovations. Hood face velocity and fan flow rate were measured and the smoke visualization technique was used to evaluate the capability of protecting worker's breathing zone. The concentrations of PM_0.3 were measured at points not adjacent to cooking equipment because these concentrations fluctuate greatly. Results: Mean hood face velocity increased from 0.29 m/s before renovation to 0.7m/s after renovation. The concentrations of PM_0.3 showed a roughly 95% reduction. Concentrations of CO showed more than a 75% reduction. Smoke visualization showed greater protection of workers' breathing zone. Conclusions: Advanced design techniques for school kitchen ventilation systems were applied to renovate old kitchen ventilation systems. The performance of the new kitchen ventilation systems was nearly excellent. Further improvement of design techniques is still needed, however.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.99-104
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• 2006

Accurate flow rate distribution has been become a very important part for controling of air change rate since the introduction of house ventilation system. An inappropriate selection of fan due to Incorrect prediction of friction loss makes waste energy. The purpose of this study is to recognize applicability of T-Method at house ventilation system by comparing experiment with T-method, The result of this study is as follows Flow rate is small amount in a house, so duct size must be accurate. And duct design with Equal Friction Loss Method presented large error range. Equal friction loss method is not fit to applicate small amount air flow rate. T-Method predicts accurate flow rate comparatively in a house ventilation system. Error range was 3.5%.

• Journal of the Korean housing association
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• v.24 no.2
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• pp.61-68
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• 2013

This study has the purpose to adapt IT technology on Window Type Ventilation System for the energy saving and providing of user-centered comfortable environment. This is Derived a look at the case of the window type ventilation system and researched its IT technology for reducing energy applied to the Green Home. This indicates a solution for the established Window Type Ventilation System which can not be satisfied with user's requirement by proposing Window Type Ventilation System applied to IT technology that makes it control the intelligent, combined indoor environment system and providing information. Also, it shows energy saving efficiency of Window Type Ventilation System applied to IT technology based on the model study, analysing the performance of air-conditioning and ventilation energy saving through the experiment to compare with the established Window Type Ventilation System. The result of this study has the significance that it suggests an alternative for energy saving of housing space.