• Journal of Communications and Networks
• /
• v.3 no.4
• /
• pp.365-373
• /
• 2001

We propose a new channel reservation protocol which can reduce message delay by using a counter for detection of d source conflict in a WDM single-hop network with non-equivalent propagation delay. A source convict occurs when a source node has the right to transmit more than or equal to two messages simultaneously, which are transmitted using different wavelengths. In such a case, the source node has to newly obtain the right to transmit the message. In the proposed protocol, by using a source conflict counter a source node can detect a source conflict before a wave-length assignment is performed. Therefore, the source node can start a procedure to newly obtain the right to transmit the message which cannot be transmitted due to a source conflict. We analyse the throughput performance by taking the effect of a source conflict into account, and show that the approximate analysis and the computer simulated results are close. Also, from computer simulated results, we show that our proposed protocol can reduce mean message delay dramatically without degrading throughput performance as the offered load becomes large.

• Journal of Chest Surgery
• /
• v.46 no.4
• /
• pp.241-248
• /
• 2013

Esophageal cancer has one of the highest malignant potentials of any type of tumor. The 3-field lymph node dissection is the standard procedure in Japan for surgically curable esophageal cancer in the middle or upper thoracic esophagus. Minimally invasive esophagectomy is being increasingly performed in many countries, and several studies report its feasibility and curability; further, the magnifying effect of the thoracoscope is another distinct advantage. However, few studies have reported that minimally invasive esophagectomy is more beneficial than open esophagectomy. A recent meta-analysis revealed that minimally invasive esophagectomy reduces blood loss, respiratory complications, the total morbidity rate, and hospitalization duration. A randomized study reported that the pulmonary infection rate, pain score, intraoperative blood loss, hospitalization duration, and postoperative 6-week quality of life were significantly better with the minimally invasive procedure than with other procedures. In the future, sentinel lymph node mapping might play a significant role by obtaining individualized information to customize the surgical procedure for individual patients' specific needs.

• Journal of the Ergonomics Society of Korea
• /
• v.28 no.2
• /
• pp.9-16
• /
• 2009

The aim of this study was to evaluate the effects of the driving performance and workload according to changing driving environment and types of steering wheel. Twelve drivers who participated in this study consisted of two groups; six Japanese as the left-lane drivers who was accustomed to driving on left-hand side of the road, and six Europeans, Americans, and Korean as the right-lane drivers who was accustomed to driving on right-hand side of the road. They were asked to operate a driving simulator while using two different types of steering wheel (for the left-hand side driving and the right-hand side driving). During the experiment, a range of data were measured including driving performance, mental workload, and eye movements which were recorded in order to identify the amount of time looking towards the in-vehicle route guidance. Results indicated that the use of the steering wheel by parallel moving led to increase high attentional demand and worse glance behavior to traffic signs for the left-lane drivers. In the case of the right-lane drivers, the effects by changing driving direction were more effective than the types of steering wheel due to their habit or traits.

• Journal of the Korean Society of Safety
• /
• v.24 no.3
• /
• pp.65-70
• /
• 2009

In-vehicle route guidance information(RGI) systems have been developed with the advancement of the information and communication technologies. However, the RGI is provided by a pre-determined option, drivers occasionally pass the target intersection owing to non- or late- recognizing it. The purpose of this experiment is to examine the position of driver's tum signal operation and intersection recognition approaching at the target intersection which is difficult to identify as a preliminary research on developing the additional RGI connecting with the tum signal control. The field experiment was conducted to measure distances of the turn signal operation and intersection recognition from the target intersection according to driving lanes and landmarks at adjacent intersection. And, glance behavior to the car navigation display was evaluated by using an eye camera. The results indicate that drivers operate the turn signal after confirming a landmark in the case of the intersection with it. However, most case of driving, drivers operate the tum signal at 40 to 50m before coming to the target. To provide the additional RGI, when drivers do not operate the tum signal approaching at the target intersection based on the results, is expected to improve the traffic safety and the comfort for drivers.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1992.02a
• /
• pp.145-157
• /
• 1992

• The Korean Journal of Nuclear Medicine
• /
• v.5 no.1
• /
• pp.33-47
• /
• 1971

• 대한미세수술학회:학술대회논문집
• /
• 1995.11a
• /
• pp.83.2-84
• /
• 1995

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2005.06a
• /
• pp.75-86
• /
• 2005

• Proceedings of KHEA Conference
• /
• 1997.07a
• /
• pp.371-377
• /
• 1997

• Proceedings of the KTCVS Conference
• /
• 1993.06a
• /
• pp.124-124
• /
• 1993