• Title/Summary/Keyword: size series

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Design of Triple-band Triple Dipole Quasi-Yagi Antenna for WLAN and WiMAX Applications (무선 랜과 WiMAX 응용을 위한 삼중 대역 삼중 다이폴 준-야기 안테나 설계)

  • Yeo, Junho;Lee, Jong-Ig
    • Journal of Advanced Navigation Technology
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    • v.26 no.1
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    • pp.29-34
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    • 2022
  • In this paper, the design of a triple dipole quasi-yagi antenna operating in the 2.45 GHz and 5 GHz wireless LAN frequency bands and the 3.5 GHz WiMAX frequency band was studied. The proposed quasi-Yagi antenna consists of three dipoles connected in series with a V-shaped ground plane. The longest half-bow-tie-shaped dipole resonates in the 2.45 GHz band, whereas the medium-length dipole resonates at 3.5 GHz. The shortest dipole resonates in the 5 GHz band. By adjusting the length and width of the dipoles and the spacings between the dipoles, a triple-band directional antenna operating in the 2.45 GHz, 3.5 GHz, and 5 GHz bands are designed, and fabricated on an FR4 substrate with a size of 45 mm × 55 mm. It was confirmed that the fabricated antenna operates in the designed triple bands of 2.32-2.57 GHz, 3.26-3.69 GHz, and 4.50-6.56 GHz for a voltage standing wave ratio less than 2. Gain is maintained above 3 dBi in the three bands.

Large-scale testing and numerical study on an innovative dovetail UHPC joint subjected to negative moment

  • Zhang, Qifeng;Feng, Yan;Cheng, Zhao;Jiao, Yang;Cheng, Hang;Wang, Jingquan;Qi, Jianan
    • Computers and Concrete
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    • v.30 no.3
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    • pp.175-183
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    • 2022
  • To study the working mechanism and size effect of an innovative dovetail UHPC joint originated from the 5th Nanjing Yangtze River Bridge, a large-scale testing subject to negative bending moment was conducted and compared with the previous scaled specimens. The static responses, i.e., the crack pattern, failure mode, ductility and stiffness degradation were analyzed. It was found that the scaled specimens presented similar working stages and working mechanism with the large-scale ones. However, the post-cracking ductility and relative stiffness degradation all decrease with the enlarged length/scale, apart from the relative stiffness after flexural cracking. The slab stiffness at the flexural cracking stage is 90% of the initial stiffness while only 24% of the initial stiffness reserved in the ultimate stage. Finite element model (FEM) was established and compared with the experiments to verify its effectiveness in exploring the working mechanism of the innovative joint. Based on this effective method, a series of FEMs were established to further study the influence of material strength, pre-stressing level and ratio of reinforcement on its deflection-load relationship. It is found that the ratio of reinforcement can significantly improve its load-carrying capacity among the three major-influenced factors.

Large myxomatous odontogenic tumor in the jaw: a case series

  • Nguyen, Truc Thi Hoang;Eo, Mi Young;Cho, Yun Ju;Myoung, Hoon;Kim, Soung Min
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.47 no.2
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    • pp.112-119
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    • 2021
  • Objectives: Myxomatous odontogenic tumors (MOTs) are the third most common odontogenic tumors in the oral and maxillofacial region. Due to its slow-growing, but locally invasive nature, the tumor is usually detected by accident or only when it becomes a large mass, which causes facial deformity. Materials and Methods: Current study reports three unusual cases of MOT including huge myxoma involve the mandible in middle-aged man, MOT with ossifying fibroma pattern in mandible, and MOT in maxilla of young female patient. The diagnosis and treatment strategy of MOTs was also summarized and updated. Results: In reported three cases of patients with large MOTs, surgical treatment was indicated with fibular free flap reconstruction in the mandible and plate reconstruction in the maxilla. The tumors were successfully treated with radical resection and did not show signs of recurrence during the follow-up period. Conclusion: Surgical treatment indication depends on size, the position of the lesion, patient systemic condition and surgeon individual experience. In the case of a large tumor, radical resection and reconstruction is the standard surgical strategy. The conservative surgical treatment including enucleation with wide curettage is still under controversy. The recurrence rate for MOTs is significantly high, up to 30%, therefore long-term follow-up is essential.

Two Treatment Cases of Combined Korean Medicine for Patients with Dermatological Diseases Exacerbated by COVID-19 (COVID-19로 악화된 피부과 질환 환자의 한의 치료 2례에 대한 증례보고)

  • Kwan Hee, Lee;Jung Min, Yoo;Hyung Bin, Yoo;Dong Lim, Ha;Hye In, Jeong;Hong Jun, Kim;Kyeong Han, Kim
    • Herbal Formula Science
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    • v.30 no.4
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    • pp.351-361
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    • 2022
  • Objectives : The purpose of this study is to report the clinical effect of herbal medicine decoction on COVID-19 symptoms remaining after administering Western medicine and worsening eczema during the COVID-19 prevalence period in patients with chronic eczema. Methods : The two chronic eczema patients suffering from COVID-19 symptoms and worsening eczema received a series of herbal medicine decoction for treatment. The effectiveness of treatment was evaluated by VAS, NRS, EASI, PASI, DLQI, photography and subjective evaluation of the patient's improvement of symptoms. Results : After treatment, all symptoms of COVID-19 disappered and aggravated eczema lesions were remarkably improved in both cases. Compared to its peak, the first case shows that PASI improved by 88% and DLQI by 44%. According to photo and symptom changes, the size of the affected area of facial acne and lip eczema was decreased. The second case shows that EASI improved by 43% and DLQI by 65%. According to photo and symptom changes, redness, rash were stopped and pruritus was decreased. Conclusion : This study suggests that herbal medicine could induce effectiveness on both COVID-19 symptoms as well as chronic eczema.

Participation in Community Fatherhood Programs and Changes in Fathers' Lives: The FGI of Fathers Participating in the Healthy Family and Multicultural Family Support Centers (지역사회 아버지대상 프로그램의 참여와 아버지 삶의 변화: 건강가정다문화가족지원센터 참여 아버지에 대한 FGI 분석)

  • Lee, hyunah
    • Journal of Family Resource Management and Policy Review
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    • v.26 no.1
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    • pp.1-14
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    • 2022
  • The purpose of this study is to examine in more depth how community fatherhood programs affected the lives of fathers and their families through the FGI(focus group interview) after the end of the programs. Five father participation programs from four Healthy Family and Multicultural Family Support Centers were selected for this research. Focus groups with 3-5 individuals for each program were conducted, with a total sample size of 20 people. Using content analysis, 16 concepts were extracted and classified into seven categories and two sub-topics. Finally, based on these results, this study developed a series of suggestions for the planning of father participation programs.

A mean-absolute-deviation based method for optimizing skid sequence in shipyard subassembly

  • Lee, Kyung-Tae;Kwon, Yung-Keun
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.12
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    • pp.277-284
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    • 2022
  • In this paper, we proposes a method of optimizing the processing order of skids to minimize the span time in a conveyor environment of the shipbuilding subassembly process. The subassembly process consists of a series of fixed tasks where the required work time is varied according to the skid type. The loading order of skids on a conveyor which determines the span time should be properly optimized and the problem size exponentially increases with the number of skids. In this regard, we propose a novel method called UniDev by defining a measure of the mean-absolute-deviation about the time difference among simultaneously processed tasks and iteratively improving it. Through simulations with various numbers of skids and processes, it was observed that our proposed method can efficiently reduce the overall work time compared with the multi-start and the 2-OPT methods.

Anterior Cranial Base Reconstruction in Complex Craniomaxillofacial Trauma: An Algorithmic Approach and Single-Surgeon's Experience

  • Shakir, Sameer;Card, Elizabeth B.;Kimia, Rotem;Greives, Matthew R.;Nguyen, Phuong D.
    • Archives of Plastic Surgery
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    • v.49 no.2
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    • pp.174-183
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    • 2022
  • Management of traumatic skull base fractures and associated complications pose a unique reconstructive challenge. The goals of skull base reconstruction include structural support for the brain and orbit, separation of the central nervous system from the aerodigestive tract, volume to decrease dead space, and restoration of the three-dimensional appearance of the face and cranium with bone and soft tissues. An open bicoronal approach is the most commonly used technique for craniofacial disassembly of the bifrontal region, with evacuation of intracranial hemorrhage and dural repair performed prior to reconstruction. Depending on the defect size and underlying patient and operative factors, reconstruction may involve bony reconstruction using autografts, allografts, or prosthetics in addition to soft tissue reconstruction using vascularized local or distant tissues. The vast majority of traumatic anterior cranial fossa (ACF) injuries resulting in smaller defects of the cranial base itself can be successfully reconstructed using local pedicled pericranial or galeal flaps. Compared with historical nonvascularized ACF reconstructive options, vascularized reconstruction using pericranial and/or galeal flaps has decreased the rate of cerebrospinal fluid (CSF) leak from 25 to 6.5%. We review the existing literature on this uncommon entity and present our case series of n = 6 patients undergoing traumatic reconstruction of the ACF at an urban Level 1 trauma center from 2016 to 2018. There were no postoperative CSF leaks, mucoceles, episodes of meningitis, or deaths during the study follow-up period. In conclusion, use of pericranial, galeal, and free flaps, as indicated, can provide reliable and durable reconstruction of a wide variety of injuries.

Analytical and experimental exploration of sobol sequence based DoE for response estimation through hybrid simulation and polynomial chaos expansion

  • Rui Zhang;Chengyu Yang;Hetao Hou;Karlel Cornejo;Cheng Chen
    • Smart Structures and Systems
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    • v.31 no.2
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    • pp.113-130
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    • 2023
  • Hybrid simulation (HS) has attracted community attention in recent years as an efficient and effective experimental technique for structural performance evaluation in size-limited laboratories. Traditional hybrid simulations usually take deterministic properties for their numerical substructures therefore could not account for inherent uncertainties within the engineering structures to provide probabilistic performance assessment. Reliable structural performance evaluation, therefore, calls for stochastic hybrid simulation (SHS) to explicitly account for substructure uncertainties. The experimental design of SHS is explored in this study to account for uncertainties within analytical substructures. Both computational simulation and laboratory experiments are conducted to evaluate the pseudo-random Sobol sequence for the experimental design of SHS. Meta-modeling through polynomial chaos expansion (PCE) is established from a computational simulation of a nonlinear single-degree-of-freedom (SDOF) structure to evaluate the influence of nonlinear behavior and ground motions uncertainties. A series of hybrid simulations are further conducted in the laboratory to validate the findings from computational analysis. It is shown that the Sobol sequence provides a good starting point for the experimental design of stochastic hybrid simulation. However, nonlinear structural behavior involving stiffness and strength degradation could significantly increase the number of hybrid simulations to acquire accurate statistical estimation for the structural response of interests. Compared with the statistical moments calculated directly from hybrid simulations in the laboratory, the meta-model through PCE gives more accurate estimation, therefore, providing a more effective way for uncertainty quantification.

Impact of Land Use Land Cover Change on the Forest Area of Okomu National Park, Edo State, Nigeria

  • Nosayaba Osadolor;Iveren Blessing Chenge
    • Journal of Forest and Environmental Science
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    • v.39 no.3
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    • pp.167-179
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    • 2023
  • The extent of change in the Land use/Land cover (LULC) of Okomu National Park (ONP) and fringe communities was evaluated. High resolution Landsat imagery was used to identify the major vegetation cover/land use systems and changes around the national park and fringe communities while field visits/ground truthing, involving the collection of coordinates of the locations was carried out to ascertain the various land cover/land use types identified on the images, and the extent of change over three-time series (2000, 2010 and 2020). The change detection was analyzed using area calculation, change detection by nature and normalized difference vegetation index (NDVI). The result of the classification and analysis of the LULC Change of ONP and fringe communities revealed an alarming rate of encroachment into the protected area. All the classification features analyzed had notable changes from 2000-2020. The forest, which was the dominant LULC feature in 2000, covering about 66.19% of the area reduced drastically to 36.12% in 2020. Agricultural land increased from 6.14% in 2000 to 34.06% in 2020 while vegetation (degraded land) increased from 27.18% in 2000 to 38.89% in 2020. The magnitude of the change in ONP and surroundings showed the forest lost -247.136 km2 (50.01%) to other land cover classes with annual rate change of 10%, implying that 10% of forest land was lost annually in the area for 20 years. The NDVI classification values of 2020 indicate that the increase in medium (399.62 km2 ) and secondary high (210.17 km2 ) vegetation classes which drastically reduced the size of the high (38.07 km2 ) vegetation class. Consequent disappearance of the high forests of Okomu is inevitable if this trend of exploitation is not checked. It is pertinent to explore other forest management strategies involving community participation.

Surgery Is the Last Resort for Huge Scrotal Lymphedema: A Series of Challenging Cases

  • Yasser M. ElKiran;Amr M. Elshafei;Mohamed S. Abdelgawad;Mohammed F. Kamel;Hesham A. Sharaf-Eldeen;Mohammed A. Abdelmaksoud
    • Archives of Plastic Surgery
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    • v.50 no.2
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    • pp.182-187
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    • 2023
  • We aim to provide our surgical techniques, and outcomes of functional scrotal reduction procedures with complete preservation of the genitourinary original anatomy in a simple way without using complicated skin grafting or skin advancement flaps in Patients with huge and long-standing scrotal lymphedema 18 patients ages ranged from 14-65 with a median of 30 years. Functional scrotal and penoscrotal reduction was attained in all cases, without distortion of the genitourinary anatomy and without the need for advancement, rotational or free flaps, maximal scrotal diameter was reduced from median of 61[48-92] cms to a median of 25[21-29] cms (P<0.0001) and remained almost unchanged at the end of the follow up period 26[22-34] cms (P<0.0001). Sexual performance and voiding capacity were improved in all patients, testicular vascularity was unaffected and the Glasgow Benefit Inventory (GBI) for the quality of life showed marked enhancement in the total 55.5[50-72], general 55.5[50-72], social 100[50-100] and physical 16.6[16-33] points subscales. According to our experience, surgery remains the gold standard treatment for management of huge scrotal lymphedema, successful preservation of the genitourinary functions can be attained despite the size in most cases with excellent cosmoses.