• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.159-166
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• 2012

Many biometrics-based user authentication schemes using smart cards have been proposed to improve the security weaknesses in user authentication system. In 2010, Chang et al. proposed an improved biometrics-based user authentication scheme without concurrency system which can withstand forgery attack, off-line password guessing attack, replay attack, etc. In this paper, we analyze the security weaknesses of Chang et al.'s scheme and we have shown that Chang et al.'s scheme is still insecure against man-in-the-middle attack, off-line biometrics guessing attack, and does not provide mutual authentication between the user and the server. And we proposed the improved scheme to overcome these security weaknesses, even if the secret information stored in the smart card is revealed. As a result, the proposed scheme is secure for the user authentication attack, the server masquerading attack, the man-in-the-middle attack, and the off-line biometrics guessing attack, does provide the mutual authentication between the user and the remote server. And, in terms of computational complexities, the proposed scheme is more effective than Chang et al.'s scheme.

• The Journal of Society for e-Business Studies
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• v.17 no.4
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• pp.1-16
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• 2012

Shieh and Wang [10] recently proposed an efficient mutual authentication scheme that combined the cost-effectiveness of operations of Lee et al. [6]. scheme and the security and key agreement of Chen and Yeh scheme. Shieh and Wang [10] scheme, however, does not satisfy the security requirements against a third party (the man-in the middle, attacker) that have to be considered in remote user authentication scheme using password-based smart cards. Shieh and Wang weaknesses are the inappropriateness that it cannot verify the forged message in 3-way handshaking mutual authentication, and the vulnerability that the system (server) secret key can easily be exposed. This paper investigates the problems of Shieh and Wang scheme in the verification procedure of the forged messages intercepted by the eavesdrop. An enhanced two-way remote user authentication scheme is proposed that is safe and strong against multiple attacks by adding the ability to perform integrity check on the server and proposed scheme is not expose user password information and the system's confidential information.

• Tuberculosis and Respiratory Diseases
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• v.70 no.2
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• pp.165-169
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• 2011

Pheochromocytomas are neuroendocrine tumors of chromaffin cell that originate in the paraganglia of the adrenal medulla. Approximately 10% of pheochromocytomas are found in the extra-adrenal paraganglia and are called paragangliomas. However, cases of middle mediastinal paragangliomas are very rare. In this case, the patient presented with a voice change and a headache. A middle mediastinal soft tissue mass with marked enhancement was detected on computed tomography of the chest. The 24-hour urine catecholamine level was markedly elevated. The middle mediastinal mass was biopsied via mediastinoscopy and the resulting immunohistochemical staining was compatible with a diagnosis of middle mediastinal paraganglioma. The mass was resected surgically and the symptoms were relieved.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.709-712
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• 1989

The hamartoma is the commonest benign tumor of the lung and proved incidentally as asymptomatic coin lesion on routine chest radiologic examination, but has very low incidence, especially in endobronchial origin. The authors experienced a case of coincidental with intrapulmonary and endobronchial hamartoma. The patient, a 60-year-old man, a farmer, was admitted due to coughing and fever. Preoperative diagnosis was achieved by flexible bronchoscopic biopsy and managed by right middle lobectomy. Three lobulated masses were palpable in the right middle lobe. He was discharged on 15th postoperative day, without problem.

• Journal of the Korean Institute of Educational Facilities
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• v.7 no.1
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• pp.102-111
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• 2000

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.552-557
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• 2009

One-time passwords are used just once and discarded, which makes it more secure than the repeatedly used conventional passwords. This paper proposes a challenge-response based one-time password generator on a user's mobile phone always carried with the user. The generator can provide an additional authentication for a user to issue a money transfer request within his Internet banking session on a PC. A currently used device for Internet banking generates a password that changes every 30 seconds or so, which allows a man-in-the-middle to use it for stealing money within the 30 seconds. Unlike such a device, the proposed generator resists against the man-in-the-middle attack by a novel challenge-response scheme, provides better accessability and protection against stolen devices. As the currently used devices do, it prevents any unauthorized transfer even if the victim's all other credentials are revealed through his PC infected with spyware such as a keyboard logger.

• Journal of Korean Neurosurgical Society
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• v.42 no.6
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• pp.478-480
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• 2007

Unruptured non-traumatic dissecting aneurysm in the M4 segment of the middle cerebral artery (MCA) accompanied by complete occlusion of the ipsilateral internal cerebral artery (ICA) has never been reported. A 41-year-old man presented with an infarction manifesting as left-sided weakness and dysarthria. Magnetic resonance angiography revealed a subacute stage infarction in the right MCA territory and complete occlusion of the right ICA. Angiography demonstrated aneurysmal dilatation of the M4 segment of the right MCA. Surgery was performed to prevent hemorrhage from the aneurysm. The aneurysm was proximally clipped guided by Navigation-CT angiography and flow to the distal MCA was restored by superficial temporal artery-middle cerebral artery (STA-MCA) anastornosis. We report this rare case with literature review.