• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.05a
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• pp.138-144
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• 2007

Nowadays blogging is emerging as a new way of making a human-to-human relationship by offering personal information and opinion to others or by receiving any responses from them. The blogging activity would be also useful when they are in a movement surrounding lots of objects which are potentially interesting to them. However, immediate response from the objects is not available using legacy blogging systems. This paper, hence, aims to propose a methodology which allows the users to communicate with the objects to get useful information or get served immediately. Our approach is to let the objects act as bloggers, having their own blogs and communicating with each other and even with human.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.713-716
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• 2000

In this study, we present a mobile robot for ultrasonic scanning of weldment. magnetic Caterpillar mechanism is selected in order to travel on the inclined surface and vertical wall. A motion control board and motor driver are developed to control four DC-servo motors. A virtual device driver is also developed for the purpose of communicating between the control board and a host PC with Dual 'port ram. To provide the mobile robot with stable and accurate movement, PID control algorithm is applied to the mobile robot control. And a vision system for detecting the weld-line are developed with laser slit beam as a light source. In the experiments, movement of the mobile robot is tested inclined on a surface and a vertical wall.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.12
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• pp.1170-1178
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• 2007

Repeated hardware tests and tuning, investing cost and time, are usually required to assure a satisfactory performance of the suspension seat. In this study, an EILS(ECU-in-the-loop) method was proposed to develop a controller for a semi-active suspension seat with a MR(magneto-rheological) damper. EILS system was developed using a real-time seat dynamics model communicating with ECU hardwares under a closed loop environment utilizing Matlab/Simulink and xPC $TargetBox^{TM}$. A sky-hook based control algorithm with optimized damping coefficients was verified to reduce the energy consumption and to improve the vibration response performance.

• Journal of Chest Surgery
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• v.24 no.10
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• pp.1019-1023
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• 1991

Broncholithiasis is defined as a condition in which a concretion is present within a bronchus or a cavity in the lung communicating with a bronchus. Broncholithiasis, although recognized in antiquity by Aristotle and well known to accompany the mediastinal calcifications of tuberculosis and histoplasmosis frequently seen in our society, is rarely mentioned in recent medical literature. Esophagobronchial fistula is an uncommon finding in broncholithiasis. This report is a case of esophagobronchial fistula with broncholithiasis in 58-year-old male patient who complained paroxysmal coughing after ingestion of fluids. The fistulous tract was successfully resected and reinforced by mediastinal pleura. Broncholithiasis was confirmed by lithoptysis as the cause of previous esophagobronchial fistula.

• The Journal of Korea Robotics Society
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• v.10 no.4
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• pp.213-222
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• 2015

This paper presents a column-climbing robot with a mechanical manipulator, which can spirally go up and down a column using wheels. The developed robot can do useful works using the manipulator at the top of a column, e.g., electric pole while communicating wirelessly with an operator panel. It is driven using a battery without any power cables, and the average duration of power is at least one hour. The robot has a function to detect a work object using an optical sensor installed at the bottom of the manipulator. The spirally column-climbing robot developed is demonstrated by experimental works and also by showing it at an exhibition.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.203-206
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• 2012

The System of communication with wireless devices is experiencing a huge growth. While traditional communication paradigms deal with fixed networks, mobility raises a new set of questions, techniques, and solutions. In order to realize service mobility, there is a need of protocol that can support mobility while nodes are communicating without any disruption of their connection status. This paper proposes a handover authentication protocol for mobility support. Careful considerations must be taken in priority to security issues since many unreliable public and private resources; both networks and devices are involved. The protocol is based on public key cryptography with Diffie-Hellman algorithm which provides security against both leakage-resilience of private keys on untrustworthy devices and forward secrecy.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.133-133
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• 2001

Purpose： To determine the relationship between anatomical variation at A-com. artery area an hemodynamically induced aneurysm-mimicking findings on 3D-TOF MRA clinically a experimentally. Method： Sixty-two patients who had no aneurysm at A-com artery on DSA were evalua with MRA. MRA was performed with 1.5T MR machine(Vision, Siemens). Scan parameters o MRA included TR/TE/FA=30/6.4/25$\psi$$\circledR$˙¡, 512＊192 of matrix with MIP technique. The occurrence of signal defect at shoulder area of bifurcated A-com artery on MRA was evalua for the relationship between the symmetricity of bilateral ACA and the patency of A-c artery. DSA images were acquired at both ICA and VA. To analyze hemodynamical facto of signal defect, experimental studies of MRA and DSA were peformed with elastic silic phantom using conducting pulsatile pump. We also compared the results with those o computational fluid dynamics(CFD).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2375-2393
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• 2016

Key agreement is paramount in secure wireless communications. A promising approach to address key agreement schemes is to extract secure keys from channel characteristics. However, because channels lack randomness, it is difficult for wireless networks with stationary communicating terminals to generate robust keys. In this paper, we propose a Robust Secure Key Agreement (RSKA) scheme from Received Signal Strength (RSS) in stationary wireless networks. In order to mitigate the asymmetry in RSS measurements for communicating parties, the sender and receiver normalize RSS measurements and quantize them into q-bit sequences. They then reshape bit sequences into new l-bit sequences. These bit sequences work as key sources. Rather than extracting the key from the key sources directly, the sender randomly generates a bit sequence as a key and hides it in a promise. This is created from a polynomial constructed on the sender's key source and key. The receiver recovers the key by reconstructing a polynomial from its key source and the promise. Our analysis shows that the shared key generated by our proposed RSKA scheme has features of high randomness and a high bit rate compared to traditional RSS-based key agreement schemes.

• The Korean Journal of Pain
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• v.10 no.1
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• pp.121-123
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• 1997

Stellate ganglion block(SGB) is frequently performed to relieve a patient from headache of various. We experienced a rare case of subarachnoid hemorrhage by aneurysmal rupture after SGB. A 46-year-old female patient diagnosed with tension headache, and normal MRI finding consulted our pain clinic. We performed right SGB in combination with greater occipital nerve block. The next day, we performed left SGB with 6 ml of 0.25% bupivacaine. She had no evidence of subarachnoid block or intravascular injection. 15 minutes after injection, she abruptly developed convulsion and loss of consciousness. She was given artificial respiration with oxygen. The diagnosis of ruptured left posterior communicating aneurysm was confirmed by 4-vessels angiography.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.1084-1087
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• 1989

Subannular aortic aneurysm is a word-wide rare disease entity occurring predominantly in young black men. In Korea, there has been no report. We report one patient, 46 years old man, who had been operated urgently because of acute aortic insufficiency and aortic valvular vegetation after antibiotics treatment of Subacute bacterial endocarditis for 6wks. At the operative field, We found the bulging aneurysmal mass between the aorta and superior vena cava above the right pulmonary artery, which has subannular communicating opening into the left ventricular cavity, beneath the anterior commissure of the bicuspid aortic valve. Pathologic findings are consistent with "portion of vascular wall with features of aneurysm.* The patients survived aortic valve replacement and patch closure of subannular aneurysm, with no symptoms at one-year postoperative follow-up.w-up.