• Journal of Biomedical Engineering Research
• /
• v.25 no.6
• /
• pp.599-604
• /
• 2004

Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

• Journal of Intelligence and Information Systems
• /
• v.19 no.3
• /
• pp.45-55
• /
• 2013

Thereby using smartphone and mobile device be more popular the more people utilize mobile device in many area such as education, news, financial. In January, 2007 Apple release i-phone it touch off rapid increasing in user of smartphone and it create new market and these broaden its utilization area. Smartphone use WiFi or 3G mobile radio communication network and it has a feature that can access to internet whenever and anywhere. Also using smartphone application people can search arrival time of public transportation in real time and application is used in mobile banking and stock trading. Computer's function is replaced by smartphone so it involves important user's information such as financial and personal pictures, videos. Present smartphone security systems are not only too simple but the unlocking methods are spreading out covertly. I-phone is secured by using combination of number and character but USA's IT magazine Engadget reveal that it is easily unlocked by using combination with some part of number pad and buttons Android operation system is using pattern system and it is known as using 9 point dot so user can utilize various variable but according to Jonathan smith professor of University of Pennsylvania Android security system is easily unlocked by tracing fingerprint which remains on the smartphone screen. So both of Android and I-phone OS are vulnerable at security threat. Compared with problem of password and pattern finger recognition has advantage in security and possibility of loss. The reason why current using finger recognition smart phone, and device are not so popular is that there are many problem: not providing reasonable price, breaching human rights. In addition, finger recognition sensor is not providing reasonable price to customers but through continuous development of the smartphone and device, it will be more miniaturized and its price will fall. So once utilization of finger recognition is actively used in smartphone and if its utilization area broaden to financial transaction. Utilization of biometrics in smart device will be debated briskly. So in this thesis we will propose fingerprint numbering system which is combined fingerprint and password to fortify existing fingerprint recognition. Consisted by 4 number of password has this kind of problem so we will replace existing 4number password and pattern system and consolidate with fingerprint recognition and password reinforce security. In original fingerprint recognition system there is only 10 numbers of cases but if numbering to fingerprint we can consist of a password as a new method. Using proposed method user enter fingerprint as invested number to the finger. So attacker will have difficulty to collect all kind of fingerprint to forge and infer user's password. After fingerprint numbering, system can use the method of recognization of entering several fingerprint at the same time or enter fingerprint in regular sequence. In this thesis we adapt entering fingerprint in regular sequence and if in this system allow duplication when entering fingerprint. In case of allowing duplication a number of possible combinations is $\sum_{I=1}^{10}\;{_{10}P_i}$ and its total cases of number is 9,864,100. So by this method user retain security the other hand attacker will have a number of difficulties to conjecture and it is needed to obtain user's fingerprint thus this system will enhance user's security. This system is method not accept only one fingerprint but accept multiple finger in regular sequence. In this thesis we introduce the method in the environment of smartphone by using multiple numbered fingerprint enter to authorize user. Present smartphone authorization using pattern and password and fingerprint are exposed to high risk so if proposed system overcome delay time when user enter their finger to recognition device and relate to other biometric method it will have more concrete security. The problem should be solved after this research is reducing fingerprint's numbering time and hardware development should be preceded. If in the future using fingerprint public certification becomes popular. The fingerprint recognition in the smartphone will become important security issue so this thesis will utilize to fortify fingerprint recognition research.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.1
• /
• pp.92-99
• /
• 2012

Many wildlife habitats have been destroyed and fragmented during the rapid industrialization and urbanization process in Korea. It is essential to connect these fragmented habitats to reduce road-kill of many types of endangered urban wildlife. The site selection for wildlife passages must take into account the behavior of the wildlife species for safe crossing utilizing many artificial barriers in urban areas. This study attempted to identify potential wildlife passage sites for the endangered and protected leopard cats of Gangseo Ecological Park in Seoul, Korea. A space syntax analysis, an analytical technique to objectively evaluate the spatial configurations related to passage selection, found that the integration value represents the accessibility and connectivity of spaces. In this paper, this means that the bigger the integration value, the more frequently the leopard cat passes through. The leopard cats were captured and radio-tracked for 72 hours once a month from March to June of 2009. The ArcGIS and Animal Movement of Hawth Tools were used to analyze the home range and movement paths, and Axwoman 4.0 was used to analyze space syntax. The daily average movement distance was $2.099{\pm}1.08km$. During the survey period, the leopard cats crossed over an urban expressway more than 20 times, running the risk of road-kill. The range of global integration values was 0.458~1.834, while that of the local integration was 0.210~6.061. Five sites that met across the leopard cats' movement routes and roads were selected to measure the local and global integrate values. Among these sites, the higher the integration value, the higher the road-kill possibility. Thus, two of five sites with high global and local integration values were suggested as potential wildlife passage sites for the leopard cats. Now, three tunnel passages are under construction at the suggested sites for which local integration value was highest (LI=4.369). Further studies are scheduled to verify these potential sites as suitable wildlife passages.

• Journal of the Korean association of regional geographers
• /
• v.7 no.3
• /
• pp.74-90
• /
• 2001

Serious depopulation has occurred since the rapid economic growth after $1965{\sim}1995$. As a result, nowadays most of mountain villages face difficulty in maintaining and managing their settlement, because of the elderly population and the extremely small size of the settlement. Population change is understood as the origin of depopulation problems and the criterion for the depopulation. This study aims to identify the problems of over-depopulation in rural Korea and to classify the patterns and process of follow and to provide policy alternatives. It consists with the three parts : identifying the problems of over- depopulation, classifying the socio-economic factors of fallow land, analyzing a detailed case study of follow land in over-depopulation rural area-Sangju Gun and to provide policy alternatives. The results are summarizes as follows: 1) In the study area, the amount of fallow and abandoned cultivated land has increased since 1975. With the increased urbanization, the cause of the increase in fallow and abandoned cultivated-land is the labor shortage of quantity and quality. The underlying reasons for the abandonment of farmland are poor field conditions and the lack of rented farmland. 2) The secondary cause is a relative labor shortage through specialization into intensive horticulture. In the study area, specialization into pear requires intensive labor input. It has caused a relative labor shortage. 3) The third causes are landowner and the lack of rented farmland due to labor shortage. The declining of agriculture and forestry have caused out-migration and increased non-residents' landowner. 4) The fallow patterns are devided into two types the less favored farmland fallow type, non-residents' landowner(out-migrator) fallow type. The significant causes of the increase in fallow and abandoned cultivated land are the labor shortage, intensive farming, less favored farmland conditions, non-residents' landowner. The factors which caused the follow processes in Korea are socio-economic factors (labor shortage, intensive farming, less favored farmland conditions) and cultural factor(non-residents' landowner, psychological ties between rural areas and urban areas).

• Economic and Environmental Geology
• /
• v.44 no.6
• /
• pp.463-474
• /
• 2011

The Haenam epithermal mineralized zone is located in the southwestern part of South Korea, and hosts low sulfidation epithermal Au-Ag deposit (Eunsan-Moisan) and clay quarries (Okmaesan, Seongsan, and Chunsan). Epithermal deposits and accompanying hydrothermal alteration related to Cretaceous volcanism caused large zoned assemblages of hydrothermal alteration minerals. Advanced argillic-altered rocks with mineral assemblages of alunite-quartz, alunite-dickite-quartz, and dickite-kaolinite-quartz exposed on the Okmaesan, Seongsan, and Chunsan area. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), with three visible and near infrared bands, six shortwave infrared bands, and five thermal infrared bands, was used to identify advanced argillic-altered rocks within the Haenam epithermal mineralized zone. The distinct spectral features of hydrothermal minerals allow discrimination of advanced argillic-altered rocks from non-altered rocks within the study area. Because alunite, dickite, and kaolinite, consisting of advanced argillic-altered rocks within the study area are characterized by Al-O-H-bearing minerals, these acid hydrothermal minerals have a strong absorption feature at $2.20{\mu}m$. The band combination and band ratio transformation cause increasing differences of DN values between advanced argillic-altered rock and non-altered rock. The alunite and dickite-kaolinite of advanced argillic-altered rocks from the Okmaesan, Seongsan, and Chunsan have average DN values of 1.523 and 1.737, respectively. These values are much higher than those (1.211 and 1.308, respectively) of non-altered area. ASTER images can remotely provide the distribution of hydrothermal minerals on the surface. In this way good relation between ASTER spectra analysis and field data suggests that ASTER spectral analysis can be useful tool in the initial steps of mineral exploration.

• Journal of Intelligence and Information Systems
• /
• v.16 no.3
• /
• pp.181-199
• /
• 2010

As rapid progress of population aging and strong interest in health, the demand for new healthcare service is increasing. Until now healthcare service has provided post treatment by face-to-face manner. But according to related researches, proactive treatment is resulted to be more effective for preventing diseases. Particularly, the existing healthcare services have limitations in preventing and managing metabolic syndrome such a lifestyle disease, because the cause of metabolic syndrome is related to life habit. As the advent of ubiquitous technology, patients with the metabolic syndrome can improve life habit such as poor eating habits and physical inactivity without the constraints of time and space through u-healthcare service. Therefore, lots of researches for u-healthcare service focus on providing the personalized healthcare service for preventing and managing metabolic syndrome. For example, Kim et al.(2010) have proposed a healthcare model for providing the customized calories and rates of nutrition factors by analyzing the user's preference in foods. Lee et al.(2010) have suggested the customized diet recommendation service considering the basic information, vital signs, family history of diseases and food preferences to prevent and manage coronary heart disease. And, Kim and Han(2004) have demonstrated that the web-based nutrition counseling has effects on food intake and lipids of patients with hyperlipidemia. However, the existing researches for u-healthcare service focus on providing the predefined one-way u-healthcare service. Thus, users have a tendency to easily lose interest in improving life habit. To solve such a problem of u-healthcare service, this research suggests a u-healthcare recommender system which is based on collaborative filtering principle and social network. This research follows the principle of collaborative filtering, but preserves local networks (consisting of small group of similar neighbors) for target users to recommend context aware healthcare services. Our research is consisted of the following five steps. In the first step, user profile is created using the usage history data for improvement in life habit. And then, a set of users known as neighbors is formed by the degree of similarity between the users, which is calculated by Pearson correlation coefficient. In the second step, the target user obtains service information from his/her neighbors. In the third step, recommendation list of top-N service is generated for the target user. Making the list, we use the multi-filtering based on user's psychological context information and body mass index (BMI) information for the detailed recommendation. In the fourth step, the personal information, which is the history of the usage service, is updated when the target user uses the recommended service. In the final step, a social network is reformed to continually provide qualified recommendation. For example, the neighbors may be excluded from the social network if the target user doesn't like the recommendation list received from them. That is, this step updates each user's neighbors locally, so maintains the updated local neighbors always to give context aware recommendation in real time. The characteristics of our research as follows. First, we develop the u-healthcare recommender system for improving life habit such as poor eating habits and physical inactivity. Second, the proposed recommender system uses autonomous collaboration, which enables users to prevent dropping and not to lose user's interest in improving life habit. Third, the reformation of the social network is automated to maintain the quality of recommendation. Finally, this research has implemented a mobile prototype system using JAVA and Microsoft Access2007 to recommend the prescribed foods and exercises for chronic disease prevention, which are provided by A university medical center. This research intends to prevent diseases such as chronic illnesses and to improve user's lifestyle through providing context aware and personalized food and exercise services with the help of similar users'experience and knowledge. We expect that the user of this system can improve their life habit with the help of handheld mobile smart phone, because it uses autonomous collaboration to arouse interest in healthcare.

• Journal of Chest Surgery
• /
• v.38 no.6 s.251
• /
• pp.421-427
• /
• 2005

Complete surgical resection is the most effective treatment for pT1/2N1 non-small cell lung cancer, however 5 year survival rate of these patients is about $40\%$ and the major cause of death is recurrent disease. We intended to clarify the risk factors of recurrence in completely resected pT1/2N1 non-small cell lung cancer. Material and Method: From Jan. f990 to Jul. 2003, total of 117 patients were operated for pT1/2N1 non-small cell lung cancer. The risk of recurrence according to patients characteristics, histopathologic findings, type of resection, pattern of lymph node metastasis, postoperative adjuvant treatment were evaluated retrospectively. Result: Mean age of patients was 59.3 years. There were 14 patients with T1N1 and 103 patients with T2N1 disease. Median follow-up time was 27.5 months and overall 5 year suwival rate was $41.3\%$. 5 year freedom-from recurrence rate was $54.1\%$. Recurrence was observed in $44 (37.6\%)$ patients and distant recurrence developed in 40 patients. 5 year survival rate of patients with recurence was $3.3\%$, which was significantly lower than patients without recurrence $(61.3\%,\;p=0.000).$ In multi-variate analysis of risk factors for freedom-from recurrence rate, multi-station N1 $(hazard\;ratio=1.997,\;p=0.047)$ was a poor prognostic factor. Conclusion: Multi-station N1 is the risk factor for recurrence in completely resected pT1/2N1 non-small cell lung cancer.

• Journal of Chest Surgery
• /
• v.40 no.2 s.271
• /
• pp.109-113
• /
• 2007

Background: In non-small cell lung cancer (NSCLC), malignant pleural effusion is a frequently observed com-plication, and is an important negative prognostic factor. Although many studies concerned to diagnosis and treatment of malignant pleural effusion have been performed, prognostic factors of malignant pleural effusion have rarely been investigated. This study was performed to determine the prognostic factors of malignant pleural effusion n non-small cell lung cancer. Material and Method: We evaluated 33 NSCLC patients with malignant effusion treated between January 2002 and December 2003. We analyzed possible factors: gender, age, TNM Stage, fluid analysis (pH, CEA, LDH, glucose, albumin) and treatment modality. Median survival time of each factor was calculated by Kaplan-Meier method and difference of median survival time between groups of factor compared by log-rank test. The Cox proportional hazards regression model was used to confirm the significance of prognostic factor. Results: Of the 33 patients, 23 (69.7%) patients were adenocarcinoma. The median interval of the diagnosis of lung cancer and malignant effusion was 7.3 months ($25^{th}{\sim}75^{th}:\;3.9{\sim}11.8$), and the median survival time was 3.6 months (95% Confidence Interval: $1.14{\sim}5.99$). In the univariate analysis, using the log-rank test, those with an adenocarcinoma showed a relatively longer median survival time than those of a non-adenocarcinoma (4.067 vs. 1.867 months, p=0.067) without statistical significance. In the multivariate analysis, using the Cox regression, those with a non-adenocarcinoma showed a trend of high risk of cancer death than those with an adenocarcinoma without statistical significance (Relative risk; 2.754, 95% Cl: $0.988{\sim}7.672$, p=0.053). Conclusion: We could not find an independent prognostic factor of malignant pleural effusion in NSCLC. As there was a trend of high risk of cancer death according to histology, further study will be needed.

• Radiation Oncology Journal
• /
• v.9 no.2
• /
• pp.253-263
• /
• 1991

Twenty-seven patients with unresectable extrahepatic bile duct carcinoma (n=21) or with microscopic evidence of tumor rest after aggressive surgery for extrahepatic bile duct carcinoma (n=6) between 1985 and 1990 were given radiotherapy consisting intentionally external radiotherapy and/or intraluminal therapy using Gamma-Med 12i (192-Ir) high dose rate (HDR) remote control afterloading system following bile drainage procedures and Gianturco stent insertion. The objectives of this study has been to assess the feasibility and effects on survival of a combination of external radiotherapy and brachytherapy with which we hope to achieve optimal loco-regional control for patients with unresectable extrahepatic bile duct tumors. Sixteen patients were men and eleven were women, and the mean age was 58 years (34-70). 10MV X-ray was used for radiation therapy, with the total dose ranging from 45 Gy to 55 Gy, and intraluminal brachytherapy performed after external radiotherapy, with the dose of total 15 Gy. The minimum follow up was 12 months. Failure were predominantly local-regional, without distant failure. Median survival was 10 months; 2-year actuarial survival rates was $21\%$. Median survival for common hepatic duct (CHD) cancer was 9 months; for common bile duct (CBD) cancer, was 16 months. And median survival for incomplete surgery/external radiotherapy group and external/intraluminal radiotherapy group was 10 months; for external radiotherapy alone group, was 6 months. Use of chemotherapy and/or hyperthermia were not affected in survival. Therefore, our result is that the survival rates in the group of external/intraluminal radiotherapy were comparable with ones in the group of incomplete resection/external radiotherapy, and so we believe that the aggressive local and regional radiotherapy can improve the quality of life and the survival length.

• Radiation Oncology Journal
• /
• v.24 no.1
• /
• pp.11-20
• /
• 2006

Puroose: In order to find out whether stereotactic radiation therapy (RT) using CyberKnife (CK) could improve survival rate and lower acute toxicity compared to conventional RT. Materials and Methods: From April 2003 through April 2004, 19 patients with Eastern Cooperative Oncology Group (ECOG) performance status ${\leq}3$ and locally advanced pancreas cancer without distant metastasis, evaluated by CT or PET/CT, were included. We administered stereotactic RT consisting of either 33 Gy, 36 Gy or 39 Gy in 3 fractions to 6, 4 and 9 patients, respectively, in an effort to increase the radiation dose step by step, and analyzed the survival rate and gastrointestinal toxicities by the acute radiation morbidity criteria of Radiation Therapeutic Oncology Group (RTOG). Prognostic factors of age, sex, ECOG performance score, chemotherapy, bypass surgery, radiation dose, CA 19-9, planning target volume (PTV), and adjacent organ and vessel invasion on CT scan were evaluated by Log Rank test. Results: The median survival time was 11 months with 1-year survival rate of 36.8%. During follow-up period (range $3{\sim}20$ months, median 10 months), no significant gastrointestinal acute toxicity (RTOG grade 3) was observed. In univariate analysis, age, sex, ECOG performance score, chemotherapy, bypass surgery, radiation dose, CA 19-9 level, and adjacent organ and vessel invasion did not show any significant changes of survival rate, however, patients with PTV (80 cc showed more favorable survival rate than those with PTV>80 cc (p-value<0.05). In multivariate analysis, age younger than 65 years and PTV>80 cc showed better survival rate. Conclusion: In terms of survival, the efficacy of stereotactic radiation therapy using CK was found to be superior or similar to other recent studies achieved with conventional RT with intensive chemotherapy, high dose conformal RT, intraoperative RT (IORT), or intensity modulated RT (IMRT). Furthermore, severe toxicity was not observed. Short treatment time in relation to the short life expectancy gave patients more convenience and, finally, quality of life would be increased. Consequently, this could be regarded as an effective novel treatment modality for locally advanced, unresectable pancreas cancer. PTV would be a helpful prognostic factor for CK.