• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.2 no.2
• /
• pp.19-24
• /
• 1991

This paper propose a new taegeuk shaped directional couper and verify the possibility of high power division rate in those directional coupler through the experiments. We took the taegeuk shaped structure in those proposed directional coupler to utilize a $3\lambda/4$ section of hybrid ring directional coupler actively, and calculated the branch admittances, which satisfied the condition of perfect matching and isolation in the center frequency, by even odd mode analyzing methodes. On the result, we knew that it can be realized a much higher power division rate than reported result in same circuit area within the producible resistance limit in the microstrip line, made the taegeuk shaped directional couplers with 0, 8, 16 dB power split ratio in the 10 GHz frequency using CGP - 502 plate, and confirmed the validity of theory through the experiments.

• Radiation Oncology Journal
• /
• v.9 no.1
• /
• pp.159-164
• /
• 1991

To irradiate the entire neuroaxis, bilateral parallel opposed brain fields and direct posterior spinal field have been utilized and radiation dose at the junction between abutting fields has been extensilvely studied. And several workable methods were reported to achieve uniform dose at a desired depth at the juction between abutting fields whose central axis are coplanar. But the dose distribhution at the juction of orthogonal fields has been a persistent problem in radiation oncology. Author describes a new method to solve the junction problem between abutting fields whose central axis are orthogonal. Author utilized split beam/comllimator rotation or collimator/couch rotation to avoid hot or cold spots that may arise from beam divergence. Author achieved accurate and homogeneous dose distribution by mathching the $50\%$ isodose line at the junction between orthogonal central axis beam fields.

• Archives of Plastic Surgery
• /
• v.39 no.2
• /
• pp.126-129
• /
• 2012

Background : Facial capillary malformations (CMs) rarely recede; they often become darker and raised in proportion to their growth. These malformations may hypertrophy in adulthood, resulting in increased disfigurement and dysfunction. Laser treatment is considered a first-line therapy for focal CMs, but thick wide lesions, which are accompanied by hypertrophy and have a well-circumscribed nodularity, may be treated with surgical excision and reconstruction. Methods : We retrospectively reviewed the records of 25 consecutive patients who had undergone complete or partial excisions of facial capillary malformations in our unit. After the excisions, the defects that encompassed their facial aesthetic units were subsequently covered by various methods, including primary closures, local flaps, expanded flaps, split-thickness skin grafts, and full thickness skin grafts. Results : The data demonstrated satisfactory results and reliability. Our patients were treated without significant complications, and all of the patients were moderately or fully satisfied with the outcome of their surgeries. Conclusions : Among the many reconstructive options for adult patients with facial capillary malformations, thick split-thickness skin grafts can be a good choice for the coverage of widely excised wounds.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.3C
• /
• pp.234-240
• /
• 2007

In this paper, low complexity block constrained trellis coded quantization (BC-TCQ) structures are introduced, and a predictive BC TCQ encoding method is developed for quantization of line spectrum frequencies (LSF) parameters for narrowband speech coding applications. Trellis-coded quantization(TCQ) is a form of VQ that builds the VQ codebook from interleaved constituent scalar quantization codebooks. The performance is compared to the other VQ, demonstrating reduction in spectral distortion and significant reduction in encoding complexity. The predictive BC-TCQ is about 0.47107 dB superior to the IS-641 split-VQ, 26bits/frame, in spectral distortion sense. The BC-TCQ is 64.54%, 76.93%, 2.35% of the IS-641 split-VQ, respectively, in the complexity of the additions, multiplies, comparisons.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.11
• /
• pp.2512-2520
• /
• 2013

In this paper, the T-SRR (Triple Split Ring Resonator) using MNG (mu-Negative) meta-material adapted in a low-loss bandpass filter with 3-stages is suggested. The size of the T-SRR in the proposed bandpass filter with low dielectric constant PCB can be easily controlled. And the ${\lambda}/4$ transmission line theory is applied. The proposed T-SRR and filter have the center frequency of 10 GHz with QL value of 184 for military-satellite communication system in I band. The experimental results of the filter show that the insertion and return losses are 1.44 dB and 17.3 dB with bandwidth of 10 %, respectively. The proposed filter will be redesigned by IPD material etc. should be placed here. These instructions give you guidelines for preparing papers for JICCE.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.8
• /
• pp.773-779
• /
• 2011

In order to improve fuel economy and emissions, many studies of HEV have been conducted. However, most of these studies concentrate on parallel or power-split HEVs. Series-type HEVs have some advantages over parallel and power-split HEVs. One is that the engine is operated at high efficiency since the engine and the driveshaft are decoupled. Nevertheless, the optimization of the powertrain system of series HEV has not been specifically addressed. We conduct an optimization of the generation system of a series HEV based on the series HEV bus. The main objectives are to simulate the system and to compare the fuel economies of conventional and optimized generation systems.

• Archives of Plastic Surgery
• /
• v.38 no.5
• /
• pp.711-714
• /
• 2011

Purpose: Angiosarcoma is a rare malignant neoplasm of endothelial type cells that line vessel walls. It tends to occur in aged male and the prognosis of angiosarcoma is very poor because of frequent local recurrence and early metastasis. The treatment regimen is yet to be established from its rare occurrence but the wide excision in early stage is known to be the most effective. The authors report two cases of near totally excised angiosarcoma with more than a safety margin of 5 cm. Methods: The two subjects were aged male patients, one of the two was diagnosed with angiosarcoma from our institution confirmed by the biopsy. The other one went through the wide excision with a safety margin of 2 cm and split-thickness skin graft but local recurrence was observed. The two patients underwent near total excision with more than a safety margin of 5 cm, leaving only the periosteum. After confirming that the angiosarcoma had not infiltrated the excision margin, reconstruction with split-thickness skin graft was performed. Results: Based on 6 months and 24 months post-surgery assessment, no local recurrence or remote metastasis in the lungs, liver, bones, and lymph nodes at the neck, where remote metastasis is common, was reported by the two subjects who underwent near total excision with a safety margin of 5 cm. Conclusion: Angiosarcoma has very poor prognosis from its frequent recurrence and metastasis. To enhance the survival rate of angiosarcoma patients, early diagnosis, timely surgical treatment, and radiotherapy after surgery are critical. In addition, authors suggest that it is necessary to further study the efficacy of wide excision using a wider safety margin as much as possible, and to apply this to more cases.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.1
• /
• pp.25-30
• /
• 2017

In this paper, dual band patch antenna was designed using a CSRR structure with negative values permeability which inserted into the ground plane. We propose an antenna that can be used in dual band f1(1.53GHz) and f2(1.63GHz) for satellite communications by using the CSRR placed on the backside of feeding line, which is a negative shape of SRR. The proposed antenna can be arrayed using microstrip line and can be made smaller than conventional patch antenna. The fabricated antenna has the input reflection coefficient of -12.5dB and -14.5dB at f1 and f2, and the gain of 2dB and -0.8dB, respectively. and it was confirmed that the performance was sufficient in the dual-band.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.5
• /
• pp.187-192
• /
• 2017

We investigated the effects of the CSRR-metamaterial on microstrip comb-line array antennas. Microstrip comb-line array antennas was designed with 12 radiators, gain of 16.09dBi and bandwidth of 0.24GHz in the 24GHz ISM band. The designed antenna had radiation beam perpendicular to the antenna plane, co-polarization gain of 16.09dBi and cross-polarization gain of -10.86dBi. the CSRR-metamaterial increased largely the impedance bandwidth of the antenna from 0.24GHz to 3.6GHz. however as co-polarization gain became 10.08dBi and cross-polarization gain became 14.1dBi, co-polarization was mixed with cross-polarization. And the antenna gain lowered by 1.99dB. On the investigation of the dependence on the split-direction of the CSRR rings, it showed nearly the same characteristics for up-splitted ring used case and down-splitted ring used case. However in the case of arranging up-splitted ring and down-splitted ring in alternation, co-polarization gain decreased to -1.29dBi and cross-polarization gain increased to 13.9dBi, which meant the wave was transited to cross-polarization majority wave.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.5
• /
• pp.405-412
• /
• 1992

Growth characters of dry seeded paddy rice was studied at different levels of nitrogen(N) split application (basal : immediately after irrigation : 2 weeks after irrigation: 25 days before heading: heading stage with 10 : 20 : 30 : 20 : 20%, 20 : 30 : 20 : 20 : 10%, 30 : 40 : 0 : 20 : 10%, and 100% basal of slow release urea) in tillage and no-tillage systems. On May 17 in 1990, 6kg /10a of dry seeds of a breeding line of Milyang 95 was broadcasted and covered with a power tiller. Between tillage and no-tillage systems yield and its components, lodging related characteristics, and contents of cellulose, hemicellulose and lignin of culm base were similar. Leaf area index at heading stage was higher in tillage, but lodging index was lower compared with those in no-tillage plot. Culm length, effective tiller ratio, culm base weight, 1000-grain weight, harvest index in slow release N applied plot were higher compared with those in other N treatments. Grain yield of rice among levels of N split applications was similar in tillage, but it was higher in slow release N applied plot in no-tillage if 1kg /10a of additional N was applied as urea at panicle formation stage. At early growth stage N concentration and N uptake were lower in the slow release N applied plot, but higher after heading stage compared with other N treatments. The number of tillers was lowest in slow release N applied plot during the tillering stage, but the number of panicles per hill was similar to other N treatments.