• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.5
• /
• pp.622-630
• /
• 2010

The increase of the spindle speed to enhance the productivity in ring spinning processes has been limited by yarn tension and heat generation of the traveller/ring. The main causes of yarn tension are 1) the force added directly to the yarn by the rotation of the spindle and 2) the centrifugal force exerted by the yarn balloon generated by traveller rotation. The dominant causes of heat generation are 1) the friction between the ring and traveller and 2) the friction between the traveller and yarn. These factors cause yarn end-breaks and heat damage. In the case of the staple yarn manufacturing process for PET (polyester) and nylon (a heat plasticity material), the rotational speed of the ring spinning system has deteriorated to 10,000rpm. The objective of this study was to develop a rotating ring which has dynamic stability, high productivity and a simple structure to overcome the limitations of the conventional fixed ring/traveller system. The results of this study revealed that the spinning tension could be reduced by 67.8% using the newly developed rotating ring.

• Journal of the Korean Professional Engineers Association
• /
• v.30 no.6
• /
• pp.40-58
• /
• 1997

교통정보의 지능화처리에 따라 교통 체계에서의 변화가 전개되고 있다. 특히 전세계적으로 지능화된 첨단 교통 시스템으로 ITS(Intelligent Transportation System)가 등장하여 표준화된 첨단교통 정보의 체계가 진척되고 있다. 본고에서는 ITS 분야 중에서 첨단 여행자 정보 분야인 ATIS(Advanced Traveller Information Service)에 대하여 주행 및 여행자 정보 서비스의 기능 규격을 정리하고 이의 실현 방안으로 검토되고 있는 다양한 무선 데이터 통신망의 적용을 위한 기술을 검토하고자 한다.

• Journal of Korean Society of Transportation
• /
• v.27 no.2
• /
• pp.157-168
• /
• 2009

The random utility theory and the multinomial logit model (including a more recent variant--the mixed multinomial logit) derived from it have constituted a back bone for theoretical and empirical analyses of various travel demand features including mode choice. In their empirical applications, however, it is customary to specify random utilities which are linear in modal attributes such as time and cost, and in socio-economic variables. The linearity helps easy derivation of important information such as value of travel time savings by calculating marginal rate of substitution between time and cost. In this paper the author focuses on the very linearity of the random utilities. Taking into account the fact that the mode chooser is also labour supplier, commodity consumer as well as leisure-seeker, the author sets up a maximization model of the traveller, which encompasses various economic activities of the traveller. The author derive from the model the indifference curve defined on the space of modal attributes, time and cost and investigate under what conditions the random utility of the traveller becomes linear. It turns out that there exist the conditions under which the random utility is really linear in modal attributes, but the property does not hold when the traveller has a corner solution on the space of modal attributes, or when the primary utility function of the traveller is directly affected by labour provided and/or the travel time itself. As a corollary of the analysis, a random utility is suggested, approximated up to the second order of the variables involved for empirical studies of the field.

• International Journal of Advanced Culture Technology
• /
• v.4 no.1
• /
• pp.28-30
• /
• 2016

Due to the high increment in usage and built-in advanced technology of smartphones, human activity recognition relying on smartphone sensor data has become a focused research area. In order to reduce noise of collected data, most of previous studies assume that smartphones are fixed at certain positions. This strategy is impractical for real life applications. To overcome this issue, we here investigate a framework that allows detecting the status of a traveller as idle or moving regardless the position and the direction of smartphones. The application of our work is to estimate the total energy consumption of a traveller during a trip. A number of experiments have been carried out to show the effectiveness of our framework when travellers are not only walking but also using primitive vehicles like motorbikes.

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.91-96
• /
• 2001

Diminishing fare rate to distance is widely applied in transportation field including bus, but the decision method of diminishing rate is not established. The basic concept of diminishing fare rate to distance is that passengers have a benefit according to their travel distance. Furthermore, this can be justified in the standpoint of operator because the cost of long-distance traveller is lower than that of short-distance traveller to make same income. It is essential to introduce diminishing fare rate to distance to decide diminishing rate. We suggested methodologies regarding how to decide diminishing rate on the basis of operator costs.

• 한국ITS학회:학술대회논문집
• /
• 2002.11a
• /
• pp.177-180
• /
• 2002

• Magazine of the Korea Concrete Institute
• /
• v.19 no.3
• /
• pp.38-43
• /
• 2007

• Sleep Medicine and Psychophysiology
• /
• v.2 no.2
• /
• pp.146-155
• /
• 1995

Jet lag can be defined as the cumulative physiological and psychological effects of rapid air travel across multiple time zone. The consequences of jet lag include fatigue, general malaise, sleep disturbances, and reductions of cognitive and psychomotor performance, all of which have been documented in experimental biological and air crew personnel studies. Thus authors tried to study the jet lag of natural travellers by modified self reporting sleep log. Total 61 healthy travellers was studied for 3 days before and 7 days after jet-flights across seven to ten time zone. The eastbound travelling group was 38 persons, aged 19 -70 and westbound travelling group was 23 persons, aged 13 - 69. Sleep onset time, wake-up time, sleep latency, awakening frequency on night sleep, awakening duration on night sleep, sleepiness at wake-up and nap length were evaluated. Our results suggested that the 7 to 10 time zone shift gave significant influence to traveller's sleep-wake cycles. The date which subjective physical condition was recovered on was $5.16{\pm}1.50$ day after arrivals for eastbound, while for westbound, $4.91{\pm}1.62$ day. In eastbound travelling, sleep onset time became later than baselines and could not recover until 7th day. But in westbound, it became earlier than baseline and could recover until 6th day. The mean score of 24-hour sleepiness was greater in eastboumd than westbound. Therefore the eastbound travelling caused more sleep-wake cycle disturbance and daytime dysfunction than westbound travelling. In other parameters, there was no definite difference between east and westbound. From our results, it was suggested that the symptom severity of jet lag was dependent on the travelling direction. To demonstrate more definite evidence, large sized data collections and comparision by age difference were needed.

• Sim-seong Yeon-gu
• /
• v.25 no.2
• /
• pp.123-162
• /
• 2010

The author tried to analyse a Korean fairy tale "the traveller and the fox". The essence of the story is as follows; A traveller who was wandering in mountains found a house with a light. There was a beautiful woman who was very kind to give food and shelter. But she was a fox that tried to kill him with a knife. He asked her to bring a basket of water and he broke the wall with it to run away. The fox chased and he fell down a cliff to ride on the back of a tiger. The tiger ran into a cave and give him to her babies as a prey. He killed them by throwing stones and climbed a tree out of the cave. There came foxes and the tiger and they killed each other. He came back to the village with the fur of the foxes and the tiger. The author tried to understand the contents of the story symbolically and interpret them from the perspective of analytical psychology. On conclusion, the traveller was on the individuation process and experienced the negative anima (the fox) and the negative mother archetype (the tiger) and its negative subsidiaries (the tiger's babies). He tried to be consciously alert and paid continuous attention so that he could get out of the status and get new insight. During this process, it was meaningful that he could actively get an appropriate aid of positive mother archetype and Self symbolized by the water and the tree respectively.

• Proceedings of the Korean Fiber Society Conference
• /
• 1995.04a
• /
• pp.72-72
• /
• 1995