• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.43-51
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• 2007

Frost action may cause extensive damage to building, structures, roads, railways and utility lines in seasonal frost. The research about frost heave of natural ground has been considerably performed. In late years various structures have become complicated with the development of social infrastructure maintenance. Therefore countermeasure to frost heave becomes a matter of great importance from a new viewpoint. This study was aimed at catching natural ground frost heaving force quantitatively. Frost heaving forces on circular steel plates which were set on ground surface were measured in field test. The frost heaving forces arise at freezing front propagates to the structures through frozen soil layer. Besides, a full scale model of multi-anchored retaining wall was installed in field, and the freezing lines, frost heave pressure to act on a wall block, and so on were measured. Finally, the position and shape of frost line were estimated by using numerical simulation and a method to determine replacement range was suggested with soil properties and weather data.

• Journal of Korean Neurosurgical Society
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• v.67 no.5
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• pp.568-577
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• 2024

Objective : Post-stroke shoulder pain (PSSP) is a common complication that limits the range of motion (ROM) of the shoulder, the patient's rehabilitation and in turn, affects the patients' quality of life (QoL). Several treatment modalities such as sling, positioning, strapping, functional electrical stimulation, and nerve block have been suggested in literatures, however none of the treatments had long-term effects for PSSP. In this study, the authors evaluated clinical efficacy of pulsed radiofrequency (PRF) neuromodulation on the suprascapular nerve for PSSP, and suggested it as a potential treatment with long-term effect. Methods : This retrospective case series was conducted at a single center, a private practice institution. From 2013 to 2021, 13 patients with PSSP underwent PRF neuromodulation of the suprascapular nerve. The primary outcome measure was the Visual analog scale (VAS) score. The secondary outcome measurements included the shoulder ROM, Disability assessment scale (DAS), modified Ashworth scale, modified Rankin scale (mRS), and EuroQol-5 dimension-3L questionnaire (EQ-5D-3L) scores. These parameters were evaluated before PRF modulation, immediately after PRF modulation, and every 3 months until the final follow-up visit. Results : Six men and seven women were enrolled, and all patients were followed-up for a minimum of 12 months. The mean VAS score was 7.07 points before PRF neuromodulation and 2.38 points immediately post-procedure. Shoulder ROM for abduction and flexion, DAS for pain, mRS, and EQ-5D-3L demonstrated marked improvement. No complications were reported. Conclusion : PRF neuromodulation of the suprascapular nerve is an effective modality in patients with PSSP, and has long-term effect of pain relief, improvement of QoL.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.27-38
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• 2016

This work proposes a 12b 30MS/s 0.18um CMOS SAR ADC based on low-power composite switching with an active die area of $0.16mm^2$. The proposed composite switching employs the conventional $V_{CM}$-based switching and monotonic switching sequences while minimizing the switching power consumption of a DAC and the dynamic offset to constrain a linearity of the SAR ADC. Two equally-divided capacitors topology and the reference scaling are employed to implement the $V_{CM}$-based switching effectively and match an input signal range with a reference voltage range in the proposed C-R hybrid DAC. The techniques also simplify the overall circuits and reduce the total number of unit capacitors up to 64 in the fully differential version of the prototype 12b ADC. Meanwhile, the SAR logic block of the proposed SAR ADC employs a simple latch-type register rather than a D flip-flop-based register not only to improve the speed and stability of the SAR operation but also to reduce the area and power consumption by driving reference switches in the DAC directly without any decoder. The measured DNL and INL of the prototype ADC in a 0.18um CMOS are within 0.85LSB and 2.53LSB, respectively. The ADC shows a maximum SNDR of a 59.33dB and a maximum SFDR of 69.83dB at 30MS/s. The ADC consumes 2.25mW at a 1.8V supply voltage.

• Explosives and Blasting
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• v.28 no.2
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• pp.1-16
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• 2010

This study focuses on the phenomenon that the blast damaged zone developed on rock slope surfaces can be affected by joint characteristics rather than by explosive power when the pre-splitting is applied to excavate a jointed rock slope. The characteristics of rock joints on a slope were investigated and categorized them into 4 cases. Also an image processing system has been used for comparing the distribution pattern of rock blocks. From this investigation, it was found that the rock blocks bigger than 2,000 mm occupied 42% in the case of single joint set and it showed the well efficiency of pre-splitting blast. In cases of 2~3 parallel joint sets and 2~3 intersecting joint sets are developed on rock surfaces, the rock blocks in the range of 1,000~2,000 mm occupied 43.6% and 35.8%, respectively, and it showed that the efficiency of pre-splitting was decreased. When more than 3 joint sets are randomly developed, however, the rock blocks in the range of 250~500 mm occupied 35% and there was no block bigger than 1,000 mm. This denotes that the blasting with pre-splitting was not effective. The numerical analysis using PFC2D showed that the blast damaged zone in a rock mass could be directly influenced by the pre-splitting. It is, therefore, required to investigate the discontinuity pattern on rock surfaces in advance, when the pre-splitting method is applied to excavate jointed rock slopes and to apply a flexible blating design with a consideration of the joint characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3600-3607
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• 2009

This paper describes the development of a power sensor for wireless signal over the ultra wideband range of 300~3800MHz with the detecting range of 150mW~150W. The proposed power sensor fundamentally has the function of not only detecting wireless power, but recognizing frequency and measuring VSWR. The development of the power sensor is completed through the design of dual directional coupler, design of power detector block which produces DC data using the corresponding RF input power level, and establishment of collecting the exact calibration data. The dual directional coupler has the operating frequency of 300~3800MHz with the 0.085dB of insertion loss, and directivity of 30dB at least at 3800MHz. The developed power sensor has the capability of power sensing with less than 0.25dB of resolution as well as measuring VSWR of 1.17~1.96 under the practical operating situation of very high power up to 150W at 300~3800MHz.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.2
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• pp.104-115
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• 1989

In an effort to clarify the wetted patterns of sandy loam soil under trickle irrigation conditions, the distance of wetted zone, infiltration capacity and soil wetted patterns, etc. were measured by gypsum block as soil moisture sensor located every 5 cm vertically and horizontaly in the soil bin under the such conditions as a). irrigation rates set to 2, 4, 6, 8 liters per hour b). total amount of water applied fixed to 14.62 liters per soil bin c) the hearing force of soil measured by plate penetrometer ranging from 1.04 to 1.22kg/cm$_2$ The results can be summarized as follows ; 1. The wetted distance in horizontal direction(H), the wetted distance in vertical direction(D), the horizontal infiltration capacity (iH) and the vertical infiltration capacity(in)could by explained as a function of time t. 2. The horizontal wetted distance (H) is explained by an exponetial function H= a$.$ t where b was found ranging from 021 to 026 under surface trickle irrigation, which was considered a lotlower than the classical value of 0.5 and these measurements were indifferent to the increasing irrigation rates. 3. As for the surface trickle irrigation where horizontal infiltration capacity(iH) is explained as iH = A $.$ t h, the coefficient A increases with respect to irrigation rates within the limits of 0.89~1.34. 4. In terms of surface trickle irrigation of the ratio of Dm Which is maximum vertical wetted distance to Hm, which is maximum horizontal wetted distance, found to be within range of 1.0 to 1.21. It was also noted that the value of Dm decreses when irrigation rates increases while the value of Hm changes the opposite direction. 5. The optimum location of sensors from emitter for surface trickle irrigation should he inside of hemisphere whose lateral radius is 28~30cm long and vertical radius is 10~12cm long. The distance between emitters should be within 60cm long. 6. In the study of vertical wetted distance( D) where D= a $.$ tb, the exponential coefficient b ranged from 0.61 to 0.75 in surface trickle irrigation, and from 0A9 to 0.68 for subsurface trickle irrigation. These measurements showed an increasing tendency to with respect to irrigation rates. 7. In case of vertical infiltration capacity( in), where iD= A $.$ t 1-h, the coefficient A for surface trickle irrigation found to be within range of 0.16 to 0.19 and did not show any relationships with varying degree of irrigation rates. However, the coefficient was varying from 0.09 to 0.22 and showed a tendency to increase vis-a-vis irrigation rates for subsurface trickle irrigation, in contrast. 8. In the observation of subsurface trickle irrigation, it was found that Dm/Hm ratio was within 1.52 to 1.91 and showed a decreasing tendency with respect to increasing rates of irrigation. 9. The location of sensors for subsurface trickle irrigation follows same pattern as above, with vertical distance from emitter being 10~17cm long and horizontal 22~25cm long. The location of emitter should be 50 cm. 10.The relationship between VS which is the volume of wetted soil and Q which is the total amount of water when soil is reached field capacity could be explained as VS= 2.914Q0.91and the irrigation rates showed no impacts on the above relationship.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1200-1205
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• 1998

Background: Lung cancer formation is a multistage process involving activation of protooncogene and inactivation of tumor suppressor genes. We evaluate the significance of cyclin D1, p53, bcl-2 gene mutations in patients with curatively resected stage IIIA non-small cell lung cancer(NSCLC). Material and Method: One hundred consecutive cases of stage IIIA lung cancers from patients operated on curatvely between 1990 and 1995 for which adequate paraffin blocks and clinical history were available. Immunohistochemical studies were performed on the representative tissue sections from each case by the labelled streptovidin- biotin method. Sections for cyclin D1, p53, Bcl-2 immunostaining were pretreated in a microwave oven for 10 to 20 minutes in citrate buffer before immunostaining. The overnight incubation with NCL-cyclin D1-GM for cyclin D1, with clone DO-7 for p53, with clone 124 for bcl-2 was done. Mean follow-up was 24.1 months (range 2-84 months) after operation. Result: One hundred cases of lung cancers were composed of 56 cases of squamous cell carcinoma, 37 cases of adenocarcinoma, 5 cases of adenosquamous cell carcinoma, and 2 cases of large cell carcinoma. The 5-year survival was 32.1%. The positive expression rate of cyclin D1 was 35%, p53 was 56%, and bcl-2 was 17%. But there were no correlation between cyclin D1, p53, Bcl-2 protein expression and survival. Conclusion: These observation indicate that cyclin D1, p53, bcl-2 protein overexpression might be implicated in the oncogenesis of non-small cell lung carcinomas but they have no usefulness as a prognostic marker.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.2
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• pp.37-48
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• 2008

Generally, a motion vector and a disparity vector represent the motion information of an object in a single-view of camera and the displacement of the same scene between two cameras that located spatially different from each other, respectively. Conventional H.264/AVC does not use the disparity vector in the motion vector prediction because H.264/AVC has been developed for the single-view video. But, multi-view video coding that uses the inter-view prediction structure based on H.264/AVC can make use of the disparity vector instead of the motion vector when the current frame refers to the frame of different view. Therefore, in this paper, we propose an improved motion/disparity vector prediction method that consists of global disparity vector replacement and extended neighboring block prediction. From the experimental results of the proposed method compared with the conventional motion vector prediction of H.264/AVC, we achieved average 1.07% and 1.32% of BD (Bjontegaard delta)-bitrate saving for ${\pm}32$ and ${\pm}64$ of global vector search range, respectively, when the search range of the motion vector prediction is set to ${\pm}16$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.5
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• pp.40-49
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• 2008

A Frequency synthesizer for mobile-DTV applications is implemented using $0.18{\mu}m$ CMOS process with 1.8V supply. PMOS transistors are chosen for VCO core to reduce phase noise. The measurement result of VCO frequency range is 800MHz-1.67GHz using switchable inductors, capacitors and varactors. We use varactor bias technique for the improvement of VCO gain linearity, and the number of varactor biasing are minimized as two. VCO gain deterioration is also improved by using the varactor switching technique. The VCO gain and interval of VCO gain are maintained as low and improved using the VCO frequency calibration block. The sigma-delta modulator for fractional divider is designed by the co-simualtion method for accuracy and efficiency improvement. The VCO, PFD, CP and LF are verified by Cadence Spectre, and the sigma-delta modulator is simulated using Matlab Simulink, ModelSim and HSPICE. The power consumption of the frequency synthesizer is 18mW, and the VCO has 52.1% tuning range according to the VCO maximum output frequency. The VCO phase noise is lower than -100dBc/Hz at 1MHz at 1MHz offset for 1GHz, 1.5GHz, and 2GHz output frequencies.

• Smart Media Journal
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• v.2 no.4
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• pp.60-65
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• 2013

In this paper, we propose a high-resolution disparity map generation method using a low-resolution time-of-flight (TOF) depth camera and color camera. The TOF depth camera is efficient since it measures the range information of objects using the infra-red (IR) signal in real-time. It also quantizes the range information and provides the depth image. However, there are some problems of the TOF depth camera, such as noise and lens distortion. Moreover, the output resolution of the TOF depth camera is too small for 3D applications. Therefore, it is essential to not only reduce the noise and distortion but also enlarge the output resolution of the TOF depth image. Our proposed method generates a depth map for a color image using the TOF camera and the color camera simultaneously. We warp the depth value at each pixel to the color image position. The color image is segmented using the mean-shift segmentation method. We define a cost function that consists of color values and segmented color values. We apply a weighted average filter whose weighting factor is defined by the random walk probability using the defined cost function of the block. Experimental results show that the proposed method generates the depth map efficiently and we can reconstruct good virtual view images.