• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.164-171
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• 2005

Toxicological studies have an object of detecting adverse effects of a chemical on an organism based on observed toxicity marker (i.e., serum biochemical markers and chemical-specific gene expression) or phenotypic outcome. To date, most toxicogenomic studies concentrated on hepatic toxicity. cDNA microarray analysis enable discrimination of the responses in animals exposed to different classes of hepatotoxicants. In an effort to further characterize the mechanisms of 2, 3, 7, 8,-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin)-mediated toxicity, comprehensive temporal-responsive microarray analyses were performed on hepatic tissue from Sprague-Dawley rats treated with TCDD. Hepatic gene expression profiles were monitored using custom DNA chip containing 490 cDNA clones related with toxicology. Gene expression analysis identified 26 features which exhibited a significant change. In this study, we observed that the genes related with oxidative stress in rats exposed to Dioxin, such as CYPIIA3 and glutathione S-transferase, were up-regulated at 24hr after exposure. In this study, we carried out to discover novel evidence for previously unknown gene expression patterns related to mechanism of hepatic toxicity in rats exposed to dioxin, and to elucidate the effects of dioxin on the gene expression after exposure to dioxin.

• Journal of Sensor Science and Technology
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• v.1 no.1
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• pp.43-51
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• 1992

This paper describes a noble robot sensor designed to recognize an unknown material by measuring its thermal conductivity on various ambient temperature. The excellent agreement has been obtained between the measured sensor temperature and the calculated sensor temperature by cubic spline interpolation. The active sensor to measure the thermal conductivity of a gripped object was designed and the software program using C language to discriminate objects made of different materials was developed. The temperature response characteristics of different materials on the same ambient temperature was investigated. The temperatures on three comparing points varied linearly and had parallel relation with one another in accordance with various ambient temperature.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.865-874
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• 2005

The information stored in the computer system needs to be protected from unauthorized access, malicious destruction or alteration and accidental inconsistency. In this paper, we propose an intrusion detection system based on sensor concept for defecting and preventing malicious attacks We use software sensor objects which consist of sensor file for each important directory and sensor data for each secret file. Every sensor object is a sort of trap against the attack and it's touch tan be considered as an intrusion. The proposed system is a new challenge of setting up traps against most interception threats that try to copy or read illicitly programs or data. We have implemented the proposed system on the Linux operating system using loadable kernel module technique. The proposed system combines host~based detection approach and network-based one to achieve reasonably complete coverage, which makes it possible to detect unknown interception threats.

• Informatization Policy
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• v.30 no.1
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• pp.67-88
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• 2023

The expansion of the scope of product liability is necessary because the industrial environment has changed following the enactment of the Product Liability Act. Unlike human-coded algorithms, artificial intelligence is black-boxed according to machine learning, and even developers cannot explain the results. In particular, since the cause of the problem by artificial intelligence is unknown, the responsibility is unclear, and compensation for victims is not easy. This is because software or artificial intelligence is a non-object, and its productivity is not recognized under the Product Liability Act, which is limited to movable property. As a desperate measure, productivity may be recognized if it is stored or embedded in the medium. However, it is not reasonable to apply differently depending on the medium. The EU revise the product liability guidelines that recognize product liability when artificial intelligence is included. Although compensation for victims is the value pursued by the Product Liability Act, the essence has been overlooked by focusing on productivity. Even if an accident occurs using an artificial intelligence-adopted service, however, it is desirable to present standards according to practical risks instead of unconditionally holding product responsibility.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.78-83
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• 2007

Robot collects surrounding information to recognize tile unknown environment by using various sensors such as visual, infrared ray and ultra sonic sensors. Although visual sensor is the most popular one, it has some difficulties in collecting data in dark or too bright environment due to sensitivity of the light. It also requests significant amount of calculation on collecting data from certain images with marked, straight and curved ones. As an alternative, ultra sonic sensor can simply overcome this visual sensing system's flaw and easily be used. It is easier than visual system, especially in case of collecting data on object and distance in dark environment. Ultra sonic sensor can replace the expensive visual sensing system not only in avoiding obstacles but also in reaching to the target area smoothly. The purpose of this paper is to develop the algorithm to optimize the environmental recognition, path planning and free-ranging by minimizing errors caused by inaccurate information and by considering characteristics of the ultra sonic rays such as refraction and diffusion. This paper also realizes the system that can recognize the environment and make the appropriate path planning by applying the algorithm on this moving robot.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.49-58
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• 2011

Typically, vision-based AR systems operate on the basis of prior knowledge of the environment such as a square marker. The traditional marker-based AR system has a limitation that the marker has to be located in the sensing range. Therefore, there have been considerable research efforts for the techniques known as real-time camera tracking, in which the system attempts to add unknown 3D features to its feature map, and these then provide registration even when the reference map is out of the sensing range. In this paper, we describe a real-time camera tracking framework specifically designed to track a monocular camera in a desktop workspace. Basic idea of the proposed scheme is that a real-time camera tracking is achieved on the basis of a plane tracking algorithm. Also we suggest a method for re-detecting features to maintain registration of virtual objects. The proposed method can cope with the problem that the features cannot be tracked, when they go out of the sensing range. The main advantage of the proposed system are not only low computational cost but also convenient. It can be applicable to an augmented reality system for mobile computing environment.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.256-270
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• 2023

In this study, a sliding mode (SM) controller for dynamic positioning (DP) was specifically designed for a turret connection operation of a ship or an offshore structure in which an arbitrary point on the structure could be controlled as the motion center instead of the center of mass. The SM controller allows control of the arbitrary point and provides capability to manage uncertainties in the dynamics of ships and offshore structures, external forces caused by unknown changing marine environments, and transient performance of DP systems. The Jacobian matrix included in kinematic equations of the controlled object was modified to design the SM controller to control based on an arbitrary point of ships or offshore structures. To ensure robustness of the controller, the Lyapunov stability theory was applied in the design of the SM controller. In general, for robustness in DP control, gain scheduling based on a proportional-derivative (PD) control algorithm is employed. However, finding appropriate gains for gain scheduling complicates the application of DP systems. Therefore, in this study, the SM control algorithm was considered to mitigate the complexity of the DP controller for ships and offshore structures. To validate the proposed SM control algorithm, time-domain simulations were conducted and utilized to evaluate the performance of the control algorithm. The effectiveness of the proposed SM controller was assessed by comparing simulation results with results of a conventional PD control algorithm applied in DP control.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.5
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• pp.444-450
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• 2015

The accuracy of small and low cost CCD camera is insufficient to provide data for precisely tracking unmanned aerial vehicles(UAVs). This study shows how UAV can hover on a human targeted tracking object by using CCD camera rather than imprecise GPS data. To realize this, UAVs need to recognize their attitude and position in known environment as well as unknown environment. Moreover, it is necessary for their localization to occur naturally. It is desirable for an UAV to estimate of his attitude by environment recognition for UAV hovering, as one of the best important problems. In this paper, we describe a method for the attitude of an UAV using image information of a maker on the floor. This method combines the observed position from GPS sensors and the estimated attitude from the images captured by a fixed camera to estimate an UAV. Using the a priori known path of an UAV in the world coordinates and a perspective camera model, we derive the geometric constraint equations which represent the relation between image frame coordinates for a marker on the floor and the estimated UAV's attitude. Since the equations are based on the estimated position, the measurement error may exist all the time. The proposed method utilizes the error between the observed and estimated image coordinates to localize the UAV. The Kalman filter scheme is applied for this method. its performance is verified by the image processing results and the experiment.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.3
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• pp.76-93
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• 2017

This thesis recapitulates the current status of Nujeongs(樓亭) by the Han River(漢江) from the late Joseon dynasty, and to contemplate the possible options regarding their restoration. The book Yeon-gang-jeong-sa-gi(沿江亭?記) written by Eom Gyeong-su(嚴慶遂) in 1716 was selected as an object of study. After Hanyang was selected to be the capital of Joseon, Han River was considered to be the greatest venue to visit to take some time off and enjoy the view. The nobleman of the Joseon dynasty built Nujeongs around the riverside and enjoyed boating inthe current status of Nujeongs(樓亭) Han River. Eom Gyeong-su, after traveling on a boat to personally collect information, combined such information with preexisting information to create a well-organized and thorough list of the 29 Nujeongs built by the riverbank, which can be found in his book Yeon-gang-jeong-sa-gi. It is probable that a closer look into Yeon-gang-jeong-sa-gi will reveal more information regarding the general atmosphere of the era, which focused on the history and culture of Han River, and will also enable a more thorough research involving the Han River Nujeongs. The Nujeongs listed in Yeon-gang-jeong-sa-gi were analyzed in this paper. Based on the explanations found in Yeon-gang-jeong-sa-gi, the locations of the 29 Nujeongs were checked and reconfirmed, and the origins and the meanings behind their names were analyzed. In addition, the history of the Nujeongs were recapitulated with information gained from the basis of the fact that Yeon-gang-jeong-sa-gi was written in 1716, The origin of each Nujeongs were revisited, and the history of their change and demise were analyzed. Lastly, the sceneries around each Nujeongs were analyzed based on the poetries that were written and read in the respective Nujeongs, and the general taste for the arts in the era was analyzed. Some Nujeongs remain in the form of paintings, enabling us to take a closer look at the institutions and other aspects of the era. The analysis of Yeon-gang-jeong-sa-gi by this paper has revealed the location of some Han River Nujeongs that were unknown previously. Also, the revelation of some history regarding certain Nujeongs that were unknown previously has created an opportunity for the reinterpretation of the spaces surrounding Han River, and also the opportunity for a new story. Han River has lost most of its old self due to repeated exploitation. However, there are some areas where traces of the original form remains and that may be restored, and some areas may be relocated and restored based on existing paintings. Yeon-gang-jeong-sa-gi in particular may provide us with numerous possible options to reinvigorate and restructure the riverside with a more modern interpretation, especially in relation to the Han River cruise ship, as it is a book written after traveling Han River on a boat.

• Journal of Sasang Constitutional Medicine
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• v.32 no.3
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• pp.33-45
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• 2020

Object Although Taeeum and Soyang constitutional types have bigger body shapes and higher body mass index values than those with the Soeum, the relationship between the Sasang constitutional type and bone mass density is controversial and the association of osteopenia and osteoporosis remains unknown. Therefore, we investigated the relationship between bone mineral density, osteopenia, and osteoporosis according to Sasang constitutional type. Methods A total of 2,508 participants were included in this study. Among the study participants, 1,396 had Taeeum type, 276 had Soeum type, and 836 had Soyang type, respectively. The relationships to bone mass density, osteopenia, and osteoporosis in those with Sasang constitutional type were estimated using logistic and linear regression models. Results Bone mass density was significantly higher in the order of Taeeum, Soyang, and Soeum group (p < 0.01). Soeum group in comparison with Taeeum or Soyang group was significantly associated with a high odds ratio for osteopenia and osteoporosis except in the hip and femoral neck in the comparison of Taeeum and Soeum group (p < 0.01). Moreover, the bone mass density of Soeum group decreased more rapidly as the age increased when compared with Taeeum and Soyang group. Conclusions Our findings may contribute to the early prevention and management of high-risk individuals with poor bone mass density, osteopenia, and osteoporosis using Sasang constitution medicine.