• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.32-39
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• 2008

Purpose: To evaluate the effectiveness of MRI after ACL reconstruction with femoral tunnel at 10 o'clock position. Materials and Methods: MRI findings of 29 patients after ACL reconstruction using hamstring tendon autograft were evaluated. The mean period from operation to MRI was 18.9 months($7{\sim}40$ months). Signal intensity, morphology and continuity of graft, femoral insertion, graft angle, roof impingement, cross pin breakage and position were evaluated. Those findings were compared with KT-2000, Lysholm knee score and pivot shift test. Results: There was no significant correlation between signal intensity of graft and the duration to MRI. Most common pattern of the morphology was straight, and the continuity was well-preserved. 13 cases of femoral tunnel insertion were zone 4 and 16 were zone 3. There were no roof impingement. 10 cases showed cross pin breakages, of which 5 were found at the outside of distal femoral posterior cortex. 9 showed cross pin directed posteriorly in axial view. There was no significant correlation between clinical results and cross pin breakage. Conclusion: MRI examinations after ACL reconstructions are useful to evaluate the graft status, position of the graft and cross pins. Since the direction of the cross pin is important especially in 10 o'clock femoral position, care should be taken to avoid cross pin breakage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.795-803
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• 2017

This paper describes a dual-standard cryptographic processor that efficiently integrates two block ciphers ARIA and AES into a unified hardware. The ARIA-AES crypto-processor was designed to support 128-b and 256-b key sizes, as well as four modes of operation including ECB, CBC, OFB, and CTR. Based on the common characteristics of ARIA and AES algorithms, our design was optimized by sharing hardware resources in substitution layer and in diffusion layer. It has on-the-fly key scheduler to process consecutive blocks of plaintext/ciphertext without reloading key. The ARIA-AES crypto-processor that was implemented with a $0.18{\mu}m$ CMOS cell library occupies 54,658 gate equivalents (GEs), and it can operate up to 95 MHz clock frequency. The estimated throughputs at 80 MHz clock frequency are 787 Mbps, 602 Mbps for ARIA with key size of 128-b, 256-b, respectively. In AES mode, it has throughputs of 930 Mbps, 682 Mbps for key size of 128-b, 256-b, respectively. The dual-standard crypto-processor was verified by FPGA implementation using Virtex5 device.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.26-32
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• 2013

Purpose : This study was performed to evaluate the presence and severity of Hill-Sachs (HS) lesions on MR arthrography (MRA) of shoulder in patients with Bankart lesions following anterior dislocation and to investigate their relationship with Bankart lesions and frequency of dislocations. Materials and Methods: 86 MRA of shoulder were evaluated in patients with arthroscopic Bankart repairs following anterior dislocations. The largest surface length of HS lesion on MRA and extent of Bankart lesions on arthroscopy were measured. Relationships between length of HS lesions and extent of Bankart lesions and frequency of dislocations were assessed. Results: HS lesions were identified on MRA in 78 patients. The largest surface length of HS lesion ranged from 9.3 mm to 29.6 mm (mean, 18.8 mm). The extent of Bankart lesion ranged from one to six o'clock extent (mean, 4.25 o'clock extent). Three patients had single dislocation and the other 75 patients had recurrent dislocations (mean 24.5 times). The largest surface length of HS lesions was positively correlated with extent of Bankart lesions (p = 0.001, r = 0.37), but not with frequency of dislocation. Conclusion: HS lesion was very common in patients with Bankart lesion. The severity of HS lesions was correlated with extent of Bankart lesions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1814-1823
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• 2016

LVC(live-virtual-constructive) integrated training system is a representative cyber-physical system. Each systems in a LVC system has different time domain, resolution and operation methods. So, it is very important to integrate different middlewares as a common middleware for heterogeneous systems using inter-working GWs. Especially, since the LVC system uses different time, it is necessary to study the method for guaranteeing causality and time synchronization among the events from different systems. In this study, we propose an time synchronization scheme to integrate the virtual and constructive system which use the simulation time of HLA (High Level Architecture)/ RTI (Run Time Infrastructure) into the live system based on the OMG DDS (Data Distribution Service). We propose a precise time synchronization scheme based on HLA time management and clock federate between participants and federates which are the communication objects of DDS and HLA/RTI respectively. In addition, we verified that time is well-synchronized among heterogeneous systems using the suggested scheme by implementing and demonstrating simulation applications on each middleware.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.454-464
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• 2023

This paper proposes a low-power 8-bit asynchronous SAR ADC with a sampling rate of 1 MS/s for sensor node applications. The ADC uses bootstrapped switches to improve linearity and applies a VCM-based CDAC switching technique to reduce the power consumption and area of the DAC. Conventional synchronous SAR ADCs that operate in synchronization with an external clock suffer from high power consumption due to the use of a clock faster than the sampling rate, which can be overcome by using an asynchronous SAR ADC structure that handles internal comparisons in an asynchronous manner. In addition, the SAR logic is designed using dynamic logic circuits to reduce the large digital power consumption that occurs in low resolution ADC designs. The proposed ADC was simulated in a 180-nm CMOS process, and at a 1.8 V supply voltage and a sampling rate of 1 MS/s, it consumed 46.06 𝜇W of power, achieved an SNDR of 49.76 dB and an ENOB of 7.9738 bits, and obtained a FoM of 183.2 fJ/conv-step. The simulated DNL and INL are +0.186/-0.157 LSB and +0.111/-0.169 LSB.

• Journal of Astronomy and Space Sciences
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• v.28 no.1
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• pp.55-62
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• 2011

The precise orbit determination (POD) of low earth orbiter (LEO) has complied with its required positioning accuracy by the double-differencing of observations between International GNSS Service (IGS) and LEO to eliminate the common clock error of the global positioning system (GPS) satellites and receiver. Using this method, we also have achieved the 1 m positioning accuracy of Korea Multi-Purpose Satellite (KOMPSAT)-2. However double-differencing POD has huge load of processing the global network of lots of ground stations because LEO turns around the Earth with rapid velocity. And both the centimeter accuracy and the near real time (NRT) processing have been needed in the LEO POD applications--atmospheric sounding or urgent image processing--as well as the surveying. An alternative to differential GPS for high accuracy NRT POD is precise point positioning (PPP) to use measurements from one satellite receiver only, to replace the broadcast navigation message with precise post processed values from IGS, and to have phase measurements of dual frequency GPS receiver. PPP can obtain positioning accuracy comparable to that of differential positioning. KOMPSAT-5 has a precise dual frequency GPS flight receiver (integrated GPS and occultation receiver, IGOR) to satisfy the accuracy requirements of 20 cm positioning accuracy for highly precise synthetic aperture radar image processing and to collect GPS radio occultation measurements for atmospheric sounding. In this paper we obtained about 3-5 cm positioning accuracies using the real GPS data of the Gravity Recover and Climate Experiment (GRACE) satellites loaded the Blackjack receiver, a predecessor of IGOR. And it is important to reduce the latency of orbit determination processing in the NRT POD. This latency is determined as the volume of GPS measurements. Thus changing the sampling intervals, we show their latency to able to reduce without the precision degradation as the assessment of their precision.

• Journal of Astronomy and Space Sciences
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• v.34 no.1
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• pp.45-54
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• 2017

This study examines the scale unique instruments used for astronomical observation during the Joseon dynasty. The Small Simplified Armillary Sphere (小簡儀, So-ganui) and the Sun-and-Stars Time-Determining Instrument (日星定時儀, Ilseong-jeongsi-ui) are minimized astronomical instruments, which can be characterized, respectively, as an observational instrument and a clock, and were influenced by the Simplified Armilla (簡儀, Jianyi) of the Yuan dynasty. These two instruments were equipped with several rings, and the rings of one were similar both in size and in scale to those of the other. Using the classic method of drawing the scale on the circumference of a ring, we analyze the scales of the Small Simplified Armillary Sphere and the Sun-and-Stars Time-Determining Instrument. Like the scale feature of the Simplified Armilla, we find that these two instruments selected the specific circumference which can be drawn by two kinds of scales. If Joseon's astronomical instruments is applied by the dual scale drawing on one circumference, we suggest that 3.14 was used as the ratio of the circumference of circle, not 3 like China, when the ring's size was calculated in that time. From the size of Hundred-interval disk of the extant Simplified Sundial in Korea, we make a conclusion that the three rings' diameter of the Sun-and-Stars Time-Determining Instrument described in the Sejiong Sillok (世宗實錄, Veritable Records of the King Sejong) refers to that of the middle circle of every ring, not the outer circle. As analyzing the degree of 28 lunar lodges (lunar mansions) in the equator written by Chiljeongsan-naepyeon (七政算內篇, the Inner Volume of Calculation of the Motions of the Seven Celestial Determinants), we also obtain the result that the scale of the Celestial-circumference-degree in the Small Simplified Armillary Sphere was made with a scale error about 0.1 du in root mean square (RMS).

• The KIPS Transactions:PartA
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• v.15A no.1
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• pp.61-68
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• 2008

In this paper, we propose the VLSI design of Multi-Format Video Decoder (MFD) to support video codec standards such as MPEG-2, MPEG-4, H.264 and VC-1. The target of the proposed MFD is the Full HD (High Definition) video processing needed for the high-end D-TV SoC (System-on-Chip). The size of the design is reduced by sharing the common large-size resources such as the RISC processor and the on-chip memory among the different codecs. In addition, a detachable architecture is introduced in order to easily add or remove the codecs. The detachable architecture preserves the stability of the previously designed and verified codecs. The size of the design is about 2.4 M gates and the operating clock frequency is 225MHz in the Samsung 65nm process. The proposed MFD supports more than Full-HD (1080p@30fps) video decoding, and the largest number of video codec standards known so far.

• Archives of Plastic Surgery
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• v.46 no.3
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• pp.221-227
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• 2019

Background Gynecomastia is a common condition that can cause severe emotional and physical distress in both young and older men. Patients in whom symptomatic recalcitrant gynecomastia persists for a long time are potential candidates for surgery. Methods From January 2014 to January 2016, 15 patients underwent correction of gynecomastia through a single 3-mm incision at our institution. Only patients with true gynecomastia underwent surgery with this new technique. Through the small incision, sharp dissection was performed in a clockwise and counterclockwise direction describing two half-circles. Health-related quality of life and aesthetic outcomes were evaluated using a modified version of the Breast Evaluation Questionnaire (BEQ). Results The patients' average age was 23.5 years (range, 18-28 years), and their average body mass index was $23.2kg/m^2$ (range, $19.2-25.3kg/m^2$). One case was unilateral and 14 cases were bilateral. The weight of glandular tissue resected from each breast ranged from 80 to 170 g. No excess skin was excised. Bleeding was minimal. The mean operating time was 25 minutes (range, 21-40 minutes). No complications were recorded. All lesions were histologically benign. The patients' average score was 3.5 (on a 5-point Likert scale) in all domains of the BEQ for themselves and their partners. Conclusions In this study, we demonstrated the safety and reliability of a new technique that allows mastectomy through an imperceptible 3-mm incision. We obtained high patient satisfaction scores using our surgical technique, and patients reported considerable improvement in their social, physical, and psychological well-being after surgery.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.39-49
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• 2008

AEA and ARIA are next generation standard block cipher of US and Korea, respectively, and these algorithms are used in various fields including smart cards, electronic passport, and etc. This paper addresses the first efficient unified hardware architecture of AES and ARIA, and shows the implementation results with 0.25um CMOS library. We designed shared S-boxes based on composite filed arithmetic for both algorithms, and also extracted common terms of the permutation matrices of both algorithms. With the $0.25-{\mu}m$ CMOS technology, our processor occupies 19,056 gate counts which is 32% decreased size from discrete implementations, and it uses 11 clock cycles and 16 cycles for AES and ARIA encryption, which shows 720 and 1,047 Mbps, respectively.