• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.617-623
• /
• 2020

Urban railroad vehicles carry many passengers and are the core of an urban railroad transportation system. Therefore, the dynamic performance of the vehicle must be ensured. Dynamic behaviors such as the vibration and ride comfort of railway vehicles are affected by the structure of the suspension system. We analyzed the dynamic behavior of a railway vehicle according to the suspension system of an urban railway vehicle, which is mainly operated in Korea. For two types of vehicles with different suspension structures, the vibration of the vehicles on railway tracks was measured, and dynamic behavior characteristics such as vibration, ride, and vibration reduction rate were analyzed. The result of the test shows that the vibration performance of the body is superior to that of B-bogie in the lateral direction and that of A-bogie in the vertical direction. Overall, the ride quality of the A-bogie car is superior to that of B-bogie. When analyzing the vibration attenuation rate of primary suspension system, the vibration attenuation performance of B-bogie with coil spring was superior to that of A-bogie with a conical rubber spring. The secondary suspension system has better vibration attenuation performance for A-bogie with air springs compared to coil springs.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.2
• /
• pp.193-202
• /
• 1998

The purpose of this study was to understand clothing condition of elderly men focusing on somatotype variation and satisfaction with ready-to-wear and to provide basic data in designing ready-to-wrar for the elderly men. The questionnaire method was used and one-to-one interviews were held for the elderly residents in Seoul, Deajon, Jonju, and Yeosu areas. The total of 275 questionnaires (from 148 elderly men in the 60's, 99 in the 70's and 28 in the 80's) were collected and used for statistics. SAS package was used for the statistics and the statistics were based on frequency, X2-test, ANOVA, Duncan's multifle range test. The results of the study were as follows; 1) Height (p< .05), weight (p< .001) and Rohrer index (p< .05) decreased significantly with ageing 2) The somatotypes of 75.6% were changed and the 70's 8t the 80's showed significantly (p< .05) higher changing rate compared to the 60's and more changes took place significantly (p< .001) with ageing. 3) The most preferred out wear was suit & tie and next was jumper or shirt. 4) For the mode of getting suit, the highest number 55.3%) purchased ready-to-wear, next (32.0%) was tailored and the least (12.7%) neither purchased nor tailored. The percentage of buying ready-to-wear significantly (p< .01) decreased with ageing. The main reason for getting tailor-made was not well fitting of ready-to-wear (20.7% out of 32.0%). And for the mode of getting suit, there was significant differance with income (p< .001) and pocket money (p< .01). 5) The most important factors in suit and shirt werefirst, size (fitness) and second, comfort in movement. 6) For the wearing feeling of suit, 55.3% showed discomfort. There was significant difference according to the age (p< .05) and pocket money (p< .05). The Discomfort increased with ageing and less pocket money. 7) 62.4% answered it uneasy to Pick out well fitting If comfortable suit. This showed their dissatisfaction with ready-to-wear. 8) As for the items of not well fitting, 64.4% answered in jacket, 60.8% in trousers, 46.0% in shirt. The above result shows that elderly men's somatotype changes as they age, suit is found uncomfortable and it's not easy for elders to pick out comfortable ready-to-wear. So, they seem to have a certain dissatisfaction in ready to wear. Therefore, there is a need for reorganization of size and developing pattern design according to measurement of elderly men.

• International Journal of Highway Engineering
• /
• v.20 no.2
• /
• pp.35-44
• /
• 2018

PURPOSES : The purpose of this research is to analyze the characteristics of panels that affect the evaluating results of riding quality and to evaluate the appropriateness of roughness management criteria based on ride comfort satisfaction. METHODS : In order to analyze the influence of panel characteristics of riding quality, 33 panels, consisting of civilians and experts, were selected. Also, considering the roughness distribution of the expressway, 35 sections with MRI ranging from 1.17 m/km to 4.65 m/km were selected. Each panel boarded a passenger car and evaluated the riding quality with grades from 0 to 10, and assessed whether it was satisfied or not. After removing outlier results using a box plot technique, 964 results were analyzed. An ANOVA was conducted to evaluate the effects of panel expertise, age, driving experience, vehicle ownership, and gender on the evaluation results. In addition, by using the receiver operating characteristics (ROC) curve, the MRI value, which can most accurately evaluate the satisfaction with riding quality, was derived. Then, the compatibility of MRI was evaluated using AUC as a criterion to assess whether the riding quality was satisfactory. RESULTS : Only the age of the panel participants were found to have an effect on the riding quality satisfaction. It was found that satisfaction with riding quality and MRI are strongly correlated. The satisfaction rate of roughness management criteria on new (MRI 1.6 m/km) and maintenance (MRI 3.0 m/km) expressways were 95% and 53%, respectively. As a result of evaluating the roughness management criteria by using the ROC curve, it was found that the accuracy of satisfaction was the highest at MRI 3.1-3.2 m/km. In addition, the AUC of the MRI was about 0.8, indicating that the MRI was an appropriate index for evaluating the riding quality satisfaction. CONCLUSIONS : Based on the results, the distribution of the panels' age should be considered when panel rating is conducted. From the results of the ROC curve, MRI of 3.0 m/km, which is a criterion of roughness management on maintenance expressways, is considered as appropriate.

• Journal of dental hygiene science
• /
• v.14 no.2
• /
• pp.198-206
• /
• 2014

The purpose of this study was to develop and validate tool for measuring the communication skills of dental hygienist. The survey was modified and revised to fit into Korean culture. Also the reliability and validity was tested in order to ensure the survey was properly evaluating communication skills of dental hygienists. A survey was conducted with outpatients in dental clinics located in Seoul, Gyeonggi, and Daejeon area. The 483 answers out of the total collected answers were used for the final analysis of the study, using PASW Statistics 18.0 and IBM SPSS AMOS 7.0 to measure the validity and reliability. The factor analysis showed that the communication skill of the dental hygienists was composed of three elements, namely 'being caring and respectful' communications, 'sharing information' communications and 'tending to comfort' communications to reduce pain and anxiety. The validity of the model examined by a confirmatory factor analysis satisfied most of the relevant requirements. All of the factors had the conceptual reliability and variant extracted index above the minimum requirements, ensuring reliability and concentrated validity. Also, the value of the square of the correlations between all latent factors which was larger than the square of the correlation between all of the factors, thus proving the discriment validity. Cronbach's ${\alpha}$ was 0.8, which shows high reliability level. In conclusion, it was proven that dental hygienist's communication skill measurement tool has high validity and reliability. Further, this study can be used to improve dental hygienists' communication skills. Therefore, this will improve oral health of clients and manage them.

• Science of Emotion and Sensibility
• /
• v.12 no.1
• /
• pp.77-86
• /
• 2009

A comfort evaluation of car seat clothing has been proposed for high comforts interior seat clothing. Car seat covers have received wide spread attention due to their man-machine interface working. And then, it will be necessary for measurements on delicate basic mechanical-properties, which closely relate with human touch feeling of its materials. In this research, we have utilized $KES-FB^{(R)}$(Kawabata Evaluation System) series, $^ST300{(R)}$ analogue softness tester and friction tester for measurement a physical properties. In order to consider both kansei and physical properties on interior seat covers, we firstly have established subjective words of judgement for the seat covers. Secondly, related them to the objective measurement of physical properties. Each kansei-language has clearly defined as 'Softness', 'Elasticity', 'Volume' and 'Stickiness' for the adjectives of leather car seat covers. These technical terms have correlated to physical properties in other words, h (mm), bending moment ($gf^*$cm/cm), To-Tm (mm) and ${\mu}$. At this time, fuzzy logic has utilized to predict the value of kansei language through physical values. On the basis of this result, finally it is possible to predict quality index of car seat covers using neural networks technique. In short, we develop a quality evaluation system of car seat clothing combining four physical quantities with kansei engineering.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.47 no.3
• /
• pp.12-21
• /
• 2019

In order to investigate the effect of various pavement materials (artificial grass, natural grass, and clay sand) on the human thermal environment, the microclimate data in early autumn (air temperature, humidity, wind speed, and shortwave and longwave radiation) were measured and compared on each surface. The mean air temperature, humidity and wind speed of the pavement materials did not differ significantly and showed the greatest difference in the mean radiant temperature. Natural grass, which has the highest albedo, has the highest amount of shortwave radiation. The artificial turf had the highest surface temperature and the highest amount of longwave radiation. In the human thermal environment index PET, artificial grass > clay sand > natural grass. Natural grass had a maximum 2/3 level lower and a mean 1/2 level lower in PET as compared to artificial grass. The clay sand pavement had a maximum 2/3 level lower and a mean 1/3 level lower than the artificial grass. Natural grass had a maximum 1/3 level lower than the clay sand pavement. Their UTCIs showed smaller differences than the PETs. Therefore, it is necessary to carefully choose materials from the planning stage when designing outdoor spaces, including playgrounds.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.5
• /
• pp.28-41
• /
• 2022

A road system with CV(Connected Vehicle)s, which is often referred to as a cooperative intelligent transportation system (C-ITS), provides various road information to drivers using an in-vehicle warning system. Road environments with CVs induce drivers to reduce their speed or change lanes to avoid potential risks downstream. Such avoidance maneuvers can be considered to improve driving behaviors from a traffic safety point of view. Thus, empirically evaluating how a given in-vehicle warning information affects driving behaviors, and monitoring of the correlation between them are essential tasks for traffic operators. To quantitatively evaluate the effect of in-vehicle warning information, this study develops a method to calculate compliance rate of drivers where two groups of speed profile before and after road information is provided are compared. In addition, conventional indexes (e.g., jerk and acceleration noise) to measure comfort of passengers are examined. Empirical tests are conducted by using PVD (Probe Vehicle Data) and DTG (Digital Tacho Graph) data to verify the individual effects of warning information based on C-ITS constructed in Seoul metropolitan area in South Korea. The results in this study shows that drivers tend to decelerate their speed as a response to the in-vehicle warning information. Meanwhile, the in-vehicle warning information helps drivers to improve the safety and comport of passengers.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.1245-1246
• /
• 2022

Walkability is an indicator of how much pedestrians are willing to walk and how well a walking environment is created. As walking can promote pedestrians' mental and physical health, there has been increasing focus on improving walkability in different ways. Thus, plenty of research has been undertaken to measure walkability. When measuring walkability, there are many objective and subjective variables. Subjective variables include a feeling of safety, pleasure, or comfort, which can significantly affect perceived walkability. However, these subjective factors are difficult to measure by making the walkability index more reliant on objective and physical factors. Because many subjective variables are associated with human emotional states, understanding pedestrians' emotional states provides an opportunity to measure the subjective walkability variables more quantitatively. Pedestrians' emotions can be examined through surveys, but there are social and economic difficulties involved when conducting surveys. Recently, an increasing number of studies have employed physiological data to measure pedestrians' stress responses when navigating unpleasant environmental barriers on their walking paths. However, studies investigating the emotional states of pedestrians in the walking environment, including assessing their positive emotions felt, such as pleasure, have rarely been conducted. Using wearable devices, this study examined the various emotional states of pedestrians affected by the walking environment. Specifically, this study aimed to demonstrate the feasibility of monitoring biometric data, such as electrodermal activity (EDA) and heart rate variability (HRV), using wearable devices as an indicator of pedestrians' emotional states-both pleasant-unpleasant and aroused-relaxed states. To this end, various walking environments with different characteristics were set up to collect and analyze the pedestrians' biometric data. Subsequently, the subjects wearing the wearable devices were allowed to walk on the experimental paths as usual. After the experiment, the valence (i.e., pleasant or unpleasant) and arousal (i.e., activated or relaxed) scale of the pedestrians was identified through a bipolar dimension survey. The survey results were compared with many potentially relevant EDA and HRV signal features. The research results revealed the potential for physiological responses to indicate the pedestrians' emotional states, but further investigation is warranted. The research results were expected to provide a method to measure the subjective factors of walkability by measuring emotions and monitoring pedestrians' positive or negative feelings when walking to improve the walking environment. However, due to the lack of samples and other internal and external factors influencing emotions (which need to be studied further), it cannot be comprehensively concluded that the pedestrians' emotional states were affected by the walking environment.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.27 no.2
• /
• pp.1-18
• /
• 2024

This study aimed to identify the optimal street tree planting method to improve the summer thermal environment in Seoul, Republic of Korea. The effects of road direction and street tree planting patterns on urban thermal environments using ENVI-met simulations were analyzed. The 68 scenarios were analyzed based on four road directions and 17 planting patterns. The results showed that tree planting had a reducing air temperature, mean radiant temperature, human thermal sensation (PET and UTCI). The most effective planting pattern among all scenarios was low tree height (6m), wide crown width (9m), high leaf area index (3.0), and narrow planting interval (8m). The largest improvement in the thermal environment was the northern sidewalk of the east-west road. Since this study used computer simulations, the difference from real urban spaces should be considered, and further research is needed through field measurement and consideration of more variables.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.12
• /
• pp.844-861
• /
• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.