• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.07a
• /
• pp.390-390
• /
• 2004

• Proceedings of KOSOMES biannual meeting
• /
• 2017.11a
• /
• pp.91-91
• /
• 2017

• Journal of Korean Neurosurgical Society
• /
• v.60 no.5
• /
• pp.604-609
• /
• 2017

Objective : An adjustable Ghajar guide is presented to improve the accuracy of the original Ghajar guide technique. The accuracy of the adjustable Ghajar guide technique is also investigated. Methods : The coronal adjustment angle from the orthogonal catheter trajectory at Kocher's point is determined based on coronal head images using an electronic picture archiving and communication system. For the adjustable Ghajar guide, a protractor is mounted on a C-shaped basal plate that is placed in contact with the margin of a burrhole, keeping the central $0^{\circ}$ line of the protractor orthogonal to the calvarial surface. A catheter guide, which is moved along the protractor and fixed at the pre-determined adjustment angle, is then used to guide the ventricular catheter into the frontal horn adjacent to the foramen of Monro. The adjustable Ghajar guide technique was applied to 20 patients, while a freehand technique based on the surface anatomy of the head was applied to another 47 patients. The accuracy of the ventricular catheter placement was then evaluated using postoperative computed tomography scans. Results : For the adjustable Ghajar guide technique (AGT) patients, the bicaudate index ranged from 0.23 to 0.33 ($mean{\pm}standard$ deviation [SD] : $0.27{\pm}0.03$) and the adjustment angle ranged from $0^{\circ}$ to $10^{\circ}$ ($mean{\pm}SD:5.2^{\circ}{\pm}3.2^{\circ}$). All the AGT patients experienced successful cerebrospinal fluid diversion with only one pass of the catheter. Optimal placement of the ventricular catheter in the ipsilateral frontal horn approximating the foramen of Monro (grade 1) was achieved in 19 patients (95.0%), while a suboptimal trajectory into a lateral corner of the frontal horn passing along a lateral wall of the frontal horn (grade 3) occurred in 1 patient (5.0%). Thus, the AGT patients experienced a significantly higher incidence of optimal catheter placement than the freehand catheterized patients (95.0% vs. 68.3%, p=0.024). Moreover, none of the AGT patients experienced any tract hemorrhages along the catheter or procedure-related complications. Conclusion : The proposed adjustable Ghajar guide technique, using angular adjustment in the coronal plane from the orthogonal trajectory at Kocher's point, facilitates accurate freehand placement of a ventricular catheter for hydrocephalic patients.

• IEIE Transactions on Smart Processing and Computing
• /
• v.5 no.3
• /
• pp.207-214
• /
• 2016

Optical communication systems are rapidly spread following increases in data traffic. In this work, a 32-Gb/s inductorless output buffer circuit with adjustable pre-emphasis is proposed. The proposed circuit consists of an output buffer circuit and an emphasis circuit. The emphasis circuit emphasizes the high frequency components and adds the characteristics of the output buffer circuit. We proposed a design method using a small-signal equivalent-circuit model and designed the compensation characteristics with a 65-nm CMOS process in detail using HSPICE simulation. We also realized adjustable emphasis characteristics by controlling the voltage. To confirm the advantages of the proposed circuit and the design method, we fabricated an output buffer IC with adjustable pre-emphasis. We measured the jitter and eye height with a 32-Gb/s input using the IC. Measurement results of double-emphasis showed that the jitter was 14% lower, and the eye height was 59% larger than single-emphasis, indicating that our proposed configuration can be applied to the design of an output buffer circuit for higher operation speed.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.10
• /
• pp.59-64
• /
• 2008

In this paper an adjustable linear gain equalizer which is operated from 6GHz to 18GHz in order to apply wideband RF circuit System is proposed and fabricated on $Al_2O_3$ substrate using thin film process. An adjustable linear gain equalizer is proposed to T type circuit and designed to aim on variable slope $-7dB{\sim}-13dB$ using the PIN Diode

• Advances in Energy Research
• /
• v.5 no.4
• /
• pp.289-304
• /
• 2017

Large glazed surfaces and windows become common features in modern buildings. The spread of these features was influenced by the dependence of designers on mechanical and artificial systems to provide occupants with thermal and visual comfort. Countries with hot summer and cold winter conditions, like Jordan, require maximum shading from solar radiation in summer, and maximum exposure in winter to reduce cooling and heating loads respectively. The current research aims at designing optimized double-positioned external shading device systems that help to reduce energy consumption in buildings and provide thermal and visual comfort during both hot and cold seasons. Using energy plus, a whole building energy simulation program, and radiance, Lighting Simulation Tool, with DesignBuilder interface, a series of computer simulations for energy consumption and daylighting performance were conducted for offices with south, east, or west windows. The research was based on comparison to determine the best fit characteristics for two positions of adjustable horizontal louvers on south facade or vertical fins on east and west facades for summer and winter conditions. The adjustable shading systems can be applied for new or retrofitted office or housing buildings. The optimized shading devices for summer and winter positions helped to reduce the net annual energy consumption compared to a base case space with no shading device or with curtains and compared to fix shading devices.

• Journal of the Korean Society for Railway
• /
• v.11 no.1
• /
• pp.33-38
• /
• 2008

To reduce the cost and time of transport in Eurasian railroad networks such as TKR, TCR and TSR owing to the problem of different track gauges (narrow/standard/broad gauge), it is important to develop the gauge-adjustable wheelset system to adapt easily to these gauges. Moreover, freight trains having the gauge-adjustable wheelsets should be passing various curved tracks in railroad networks. Therefore, to assure the safety of the gauge-adjustment whellset system, it is necessary to evaluate integrity of locking parts in the system using stress analysis. This study is focused on analyzing contact stress of locking parts by using FEA(finite element analysis) simulation during the gauge changeover operation and freight trains' service in the curved track, respectively.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.11 no.4
• /
• pp.349-354
• /
• 2017

In this study, we proposed a design guideline of height-adjustable wash basin which is an assistive product for personal hygiene for persons with disability. We performed biomechanical assessments using both of conventional and prototype height adjustable wash basin. Total five elderly subjects (all male, age $68.6{\pm}4.3yrs.$, height $169.8{\pm}5.7cm$, weight $70{\pm}7.7kg$) participated for the assessment test. Each joint angles were measured by using a 3D motion capture system when subjects use wash basins, and the lumbar moment of each subjects was estimated based on a human body model. From the assessment results, a design guideline which has the range of the height from 652[mm] to 1162[mm] was proposed. Then additional assessment tests with five healthy subjects ($25.8{\pm}1.8yrs.$, $175.5{\pm}5.8cm$, $74{\pm}15.7kg$) were performed in order to verify effectiveness of the design guideline. The results showed a height-adjustable wash basin applied the proposed design guideline was effective to reduce the lumbar moment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.8A
• /
• pp.794-804
• /
• 2008

In this paper, we analyze the performance of probabilistic slotted anti-collision algorithm used in EPCglobal Class-1 Generation-2 (Gen2). To increase throughput and system efficiency, and to decrease tag identification time and collision ratio, we propose new tag anti-collision algorithms, which are FAFQ (fired adjustable flamed Q) algorithm and AAFQ (adaptive adjustable framed Q) algorithm, by using QueryAdjust command. We also propose grouping method based on Gen2 to improve the efficiency of tag identification. The simulation results show that all the proposed algorithms outperform Q algorithm, and AAFQ algorithm performs the best. That is, AAFQ has an increment of 5% of system efficiency and a decrement of 4.5% of collision ratio. For FAFQ and AAFQ algorithm, the performance of grouping method is similar to that of ungrouping method. However, for Q algorithm in Gen2, grouping method can increase throughput and system efficiency, and decrease tag identification time and collision ratio compared with ungrouping method.

• Journal of electromagnetic engineering and science
• /
• v.8 no.2
• /
• pp.64-69
• /
• 2008

In this paper, we have proposed the pattern adjustable base station antenna for WCDMA applications. The proposed antenna consists of an omni-antenna(sleeve monopole) and two movable reflectors. The two reflectors can be controlled by mechanically and used to adjust the horizontal pattern of the base station antenna. The antenna was designed, fabricated, and measured. The antenna covers the entire WCDMA band for VSWR<1.4. The measured antenna gain is more than 15 dBi over the operating frequency range. By changing the angle (a) and the distance (d) of the antenna, the pattern adjustment of the proposed base station antenna is found to be possible.