• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6A
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• pp.893-899
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• 2000

WDM technology has been an emerging issue for the efficient use of optical links. WDM uses a number of different wavelengths that are assigned to each channel. The minimal number of optical transcievers and receivers should be used in a node to build an economic WDM transmission system without degrading system performance. Hence, the analysis of performance parameters such as throughput and delay is important to guarantee the WDM system performance. In this paper, the performance of a MAC protocol on a slotted WDM system that has a tunable transmitter(TTX), a tunable receiver(TRX), and a fixed receiver(FRX), respectively, on each node, was statistically analyzed. The computer simulation validates the performance analysis.

• KSBB Journal
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• v.13 no.1
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• pp.71-76
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• 1998

Tissue biosensor for mearsuring sodium channel blockers, such tetrodotoxin(TTX), saxitoxin (STX) and paralytic shellfish poisoning(PSP) consisted of frog bladder membrane, and $Na^{+}$ electrode. The proposed biosensor was applied to determine Chinese drug and dry or wet Porphyra yezonesis $Na^{+}$ channel blockers below the detection limit of the standard mouse bio-assay while the observed detection limit didn't cause human poisoning. The proposed biosensor system may be used for future $Na^{+}$ channel blockers monitoring within the marine environment.

• Biomolecules & Therapeutics
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• v.3 no.2
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• pp.149-153
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• 1995

Nitric oxide (NO) has been regarded as one of the neurotransmitters of nonadrenergic, noncholinergic (NANC) nerve stimulation in rabbit corpus cavernosum, rat gastric fundus and human intestine. PIANO (photo-induced adequate nitric oxide) is a very useful tool to investige the role of NO in various smooth muscles where NO is a mediator. The present study was undertaken to compare the physiological responses of the rat gastric smooth muscle in response to NANC nerve stimulation and to PIANO. Photolysis of L-NAME, D-NAME and streptozotocin (572) by UV light in the bathing medium caused relaxation of rat gastric fungus that contracted with carbachol, but was resistant to tetrodotoxin (TTX, 1 $\mu$M). Electrical stimulation (20 V, 2~32 Hz, 0.2 msec, 10s) of the gastric fundus, in the presence of atropine and guanethidine, induced frequency-dependent, TTX-sensitive relaxation. Sodium nitroprusside (1 nM-10 $\mu$M), a NO donor, mimicked the relaxations observed after NANC-stimulation or PIANO. Furthermore, PIANO caused UV light exposure time-dependent increase of CGMP in rat gastric fungus strips. These results provide another evidence indirectly that NO is one of the mediators of the NANC inhibitory nerve stimulation in the rat gastric fundus.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.376-381
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• 2010

In this study, field measurements on KTX, Nuriro and TTX train have been conducted at Kyeongbu and Honam line to predict the wind gust under train at the speed-up of major conventional railway lines using Kiel-probe array and multi-channel pressure scanning system. The results show that the average wind velocity during train passage normalized by train speed is independent to train speed, thus the wind gust for a given train type at the speed-up condition could be predicted. The relationship between the shape of underbody and the characteristics of the underbody wind gust has been discussed.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.2
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• pp.45-50
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• 2006

Tilting technology is to tilt the train on the curve in order to minimize centrifugal force to passengers and to improve the speed within the limits of passenger's comfort and safety. According to reports from other countries, there is 15~30% speed improvement compared to the conventional trains. Recently, the advent of World-Wide-Web(WWW) and the explosive popularity of the Internet gave birth to collaborative applications which were enabled by computers and networks as their primary media. The progress of 3D computer graphics enabled collaborative applications with 3D virtual environments or distributed virtual environments. In this paper, we explain our implementation of the Share collaboration engine which is for collaboration applications based on a distributed virtual environment. The Share collaboration engine proposes a new Share network architecture for management of participants, and it provides some synchronization methods for 3D objects in virtual collaboration. TTX_PDM is an experimental application that tries to prevent wastes of human, material and time resources in networked virtual collaboration.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.435-442
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• 2004

Tilting train allow the train to pass curve at higher speed without affecting passenger comfort. As the tilting trains run curve track about 30$\%$ higher than non-tilting trains, the centrifugal force and dynamic force will be higher. Therefore it is very important for tilting train to ensure safety against derailment, and to reduce the lateral track forces by applying light-weight design, optimized suspension design and steering mechanism. The 180 km/h Korean Tilting Train(TTX) which is now developing as a part of the Korean National R & D project, was designed and analytically verified to meet these special requirements. This paper describes the analytic study to verify the safety against derailment, especially on the wheel unloading in case of tilting actuation. The severest curve geometry and curving speed was assumed, the tilting control pattern was also assumed as trapezoidal force function applied to tilting bolster and bogie frame. For the comparison, the operation with the speed of tilting train without tilting actuation was numerically simulated and the operation with the balanced speed without tilting actuation was also numerically simulated. Through the numerical simulation of various operating case, we found that derailment quotients, wheel unloading and Q/P was not affected by tilting actuation and that the bogie of TTX was nicely designed to satisfy the safety against the derailment.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.208-209
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• 2007

The measurement system is composed of the industrial computers installed in the console and the measurement racks mounted on each car. It is utilized to accumulate the data by the communication card and the optical cable. The optical cable and power cable are coupled at the connector located in joint of train to make easy to disconnect car each other. The signal conditioner is designed to choose and to extend the channel for each sensor readily, In this study, the programs for measurement and analysis were also developed to understand the traction system characteristics of TTX. Using this measurement system, we studied that acceleration test, re-powering test and gradually powering test. From the test results, we saw the performances of the traction systems are normal.

• Journal of The Korean Society of Clinical Toxicology
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• v.12 no.2
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• pp.46-53
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• 2014

Purpose: We conducted this study in order to determine clinical features and prognostic factors in adults with acute tetrodotoxin (TTX) poisoning caused by ingestion of puffer fish. Methods: In this retrospective study, 107 patients were diagnosed with TTX poisoning. The subjects were divided into two groups according to duration of treatment; Group I, patients were discharged within 48 hours (n=76, 71.0%), Group II patients were discharged after more than 48 hours (n=31, 29.0%). Group II was subsequently divided into two subgroups [IIa (n=12, 11.2%), IIb (n=19, 17.8%)] according to the need for mechanical ventilation support. Results: In multivariable logistic regression analysis, the predictors of the need for treatment over 48 hours were dizziness (odds ratio [OR], 4.72; 95% confidence intervals [CI], 1.59-12.83), time interval between onset of symptom and ingestion (OR, 0.56; 95% CI, 0.16-0.97), $PaCO_2$<35 mmHg (OR, 8.37; 95% CI, 2.37-23.59). In addition, predictors of the need for mechanical ventilation were a time interval between onset of symptoms and ingestion (OR, 0.54; 95% CI, 0.11-0.96) and $PaCO_2$<35 mmHg (OR, 5.65; 95% CI, 1.96-18.66). Conclusion: Overall, dizziness, time interval between onset of symptoms and ingestion, ${\Delta}DBP$ and $PaCO_2$<35 mmHg predict the need for treatment over 48 hours, time interval between onset of symptoms and ingestion and $PaCO_2$<35 mmHg predict the need for mechanical ventilation support after acute TTX poisoning.

• 시스템엔지니어링워크숍
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• s.4
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• pp.65-69
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• 2004

Abstract Tilting train has been developed to increase the oprational speed of the trains on conventional lines which have many curves. This train are tilted at curves to compensate for unbalanced carbody centrifugal acceleration to a greater extent than compensation produced by the track cant, so that passengers do not feel centrifugal acceleration and thus trains can run at higher speed at curves. This paper developed PDM(product data management) to make a system engineering of TTX(Tilting Train eXpress) with maximum operation speed 180 km/h.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.800-805
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• 2005

In this study, control schemes are proposed for a propulsion system of TTX(Tilting Train eXpress). In developed traction converter, unity power factor control, compensation method of dc link voltage have been applied. Output current of converter contains harmonic ripple at twice input ac line frequency, which causes a ripple in the dc link voltage so that beatless control is developed in inverter system to reduce the pulsating torque current. This system is verified by the system modelling and prototype test.