• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.330-339
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• 2008

Ground-based interceptors(GBI) comprise a major element of the strategic defense against hostile targets like Intercontinental Ballistic Missiles(ICBM) and reentry vehicles(RV) dispersed from them. An optimum design of the subsystems is required to increase the performance and reliability of these GBI. Propulsion subsystem design and optimization is the motivation for this effort. This paper describes an effort in which an entire GBI missile system, including a multi-stage solid rocket booster, is considered simultaneously in a Genetic Algorithm(GA) performance optimization process. Single goal, constrained optimization is performed. For specified payload and miss distance, time of flight, the most important component in the optimization process is the booster, for its takeoff weight, time of flight, or a combination of the two. The GBI is assumed to be a multistage missile that uses target location data provided by two ground based RF radar sensors and two low earth orbit(LEO) IR sensors. 3Dimensional model is developed for a multistage target with a boost phase acceleration profile that depends on total mass, propellant mass and the specific impulse in the gravity field. The monostatic radar cross section (RCS) data of a three stage ICBM is used. For preliminary design, GBI is assumed to have a fixed initial position from the target launch point and zero launch delay. GBI carries the Kill Vehicle(KV) to an optimal position in space to allow it to complete the intercept. The objective is to design and optimize the propulsion system for the GBI that will fulfill mission requirements and objectives. The KV weight and volume requirements are specified in the problem definition before the optimization is computed. We have considered only continuous design variables, while considering discrete variables as input. Though the number of stages should also be one of the design variables, however, in this paper it is fixed as three. The elite solution from GA is passed on to(Sequential Quadratic Programming) SQP as near optimal guess. The SQP then performs local convergence to identify the minimum mass of the GBI. The performance of the three staged GBI is validated using a ballistic missile intercept scenario modeled in Matlab/SIMULINK.

• 대한조선학회지
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• 제11권1호
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• pp.9-16
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• 1974

To contribute towards more accurate estimation of the virtual inertia coefficient for the horizontal vibration of ships, three dimensional correction factor $J_H$ for the added mass of finitely long elliptic prismatic bars in horizontal vibration in a free surface of an ideal fluid are calculated. In the problem formulation Dr. T. Kumai's quasi-finite length concept[1,11,12] is employed. Now that, in Dr. Kumai's work[1] for the horizontal vibration the mathematical model was a circular cylinder, the principal aim of the authors' work is to investigate the influence of the beam-draft ratio B/T on $J_H$. The numerical results of this work are shown in Fig.3 graphically, from which we may recognize that the influence of B/T on $J_H$ is remarkable as much as that of the length-draft ratio L/T(refer to Fig.1 also). In Fig.3 the curves for B/T=2.00 are of those based on Dr. Kumai's result[1]. On the other hand, the experimental data obtained by Burril et al.[9] for the horizontal vibration of finitely long prismatic bars of various cross-section shapes are compared with the theoretical added mass coefficients defined by combination of the authors' $J_H$ from Fig.3 and two dimensional coefficients $C_H$ obtained by Lewis form approximation for the corresponding sections. They are in reasonable correspondence with each other as shown in Fig.2. Finally, considering that the longitudinal profile of full-form ship's hull is well resembled to that of an elliptic cylinder and that the influences of other factors such as the sectional area coefficient and the shape of section contour itself can be well merged in the two dimensional added mass coefficient, the authors recommend that the data given in Fig.3 may be successfully adopted for the three dimensional correction factor the added mass in the horizontal vibration of hull-form ships.

• Journal of the Optical Society of Korea
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• 제16권4호
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• pp.331-335
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• 2012

A miniaturized laser beam transmitter, in which a visible laser module at ${\lambda}$=650 nm is precisely stacked upon an infrared (IR) module at ${\lambda}$=905 nm, has been proposed and constructed to provide an IR collimated beam in conjunction with a collinear monitoring visible beam. In particular, the IR beam is selectively dispersed through a perforated sheet diffuser, so as to create a rapidly diverging close-range beam in addition to a highly defined long-range beam simultaneously. The complementary close-range beam plays a role in mitigating the blind region in the vicinity of the transmitter, which is inevitably missed by the main long-range beam, thereby uniformly extending the transmitter's effective trajectory that is sensed by a receiver. The proposed transmitter was designed through numerical simulations and then fabricated by incorporating a diffuser sheet, perforated with an aperture of 2 mm. For the manufactured transmitter, the IR long-range beam was observed to have divergences of ~2.3 and 1.6 mrad in the fast and slow axes, respectively, while the short-range beam yielded a divergence of ~24 mrad. The angular alignment between the long-range IR and visible beams was as accurate as ~0.5 mrad. According to an outdoor feasibility test involving a receiver, the combination of the IR long- and short-range beams was proven to achieve a nearly uniform trajectory over a distance ranging up to ~600 m, with an average detectable cross-section of ${\sim}60{\times}80cm^2$.

• 대한한방소아과학회지
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• 제35권4호
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• pp.112-124
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• 2021

Objectives The aim of this study is to examine the effects of Pediatric Tuina Massage (PTM) as a treatment of Chlidren's Epilepsy (CE) and to seek guidance for future follow-up studies and the use of Pediatric Tuina Massage (PTM) in clinical setting. Methods The articles were obtained from the China National Knowledge Infrastructure (CNKI) from 2000 to 2021 by key words 'epilepsy', '癲癎', '癲癎病', 'infantile spasm', '婴幼儿痉挛', '小儿发作', '婴幼儿痉挛' and '推拿', '按摩', 'Tuina', 'Chuna', 'massage' in cross combination way. Results Seven articles were selected and analyzed by authors, years published, characteristics, diagnostic criteria, treatment methods and contents, treatment periods, evaluation criteria and research results. Also, stability and side effects were reviewed, and the qualities of the randomized controlled trials (RCT) were evaluated according to Risks of Bias 2 (RoB 2). All studies using Pediatric Tuina Massage (PTM) treatment have achieved effective therapeutic results for treating Children's epilepsy (CE). Conclusion Pediatric Tuina Massage (PTM) is economical, safe without side effects and non-invasive, but still produce a good effect. Also, it is a good treatment option for children who feels anxious of ordinary Korean Medical treatment such as acupuncture, moxa, herbal medicine, which also results in good compliance with the treatment. In addition, it is possible to enhance therapeutic effect by combining it with pharmacological therapies in treating children's epilepsy (CE). Therefore, Pediatric Tuina Massage (PTM) provides an essential clinical basis in guiding further studies for the treatment of CE.

• Annals of Coloproctology
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• 제34권6호
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• pp.312-316
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• 2018

Purpose: Anemia is associated with poor treatment results for a variety of cancers. The effect of low hemoglobin levels on long-term outcomes after the treatment of patients with an anal squamous cell carcinoma (SCC) remains unclear. For that reason, this study aimed to investigate the effect of anemia on treatment outcomes following chemoradiation for an anal SCC. Methods: This was a retrospective study of all patients who underwent curative treatment for an anal SCC between 2009 and 2015 at 2 trusts in the United Kingdom. Data were collated from prospectively collected cancer databases and were cross-checked with operating-room records and records in the hospitals' patient management systems. Results: We identified 103 patients with a median age of 63 years (range, 36-84 years). The median overall survival was 39 months (range, 9-90 months), and the disease-free survival was 36 months (range, 2-90 months). During the follow-up period, 16.5% patients died and 13.6% patients developed recurrence. Twenty-two people were anemic prior to treatment, with a female preponderance (20 of 22). No differences in disease-free survival (P = 0.74) and overall survival (P = 0.12) were noted between patients with anemia and those with normal hemoglobin levels. On regression the analysis, the combination of anemia, the presence of a defunctioning colostomy, lymph-node involvement and higher tumor stage correlated with poor overall survival. Conclusion: In this study, anemia did not influence disease-free survival or overall survival. We suggest that the interaction between anemia and survival is more complex than previously demonstrated and potentially reliant on other coexisting factors.

• 한국보건간호학회지
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• 제33권2호
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• pp.228-241
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• 2019

Purpose: The purpose of this study was to evaluate the prevalence, awareness, treatment and control of hypertension, diabetes, and dyslipidemia among women with rheumatoid arthritis. Methods: This cross-sectional study of 288 women with rheumatoid arthritis was conducted in a university-affiliated hospital. Data were collected by reviewing the women's medical charts and self-report questionnaires. Results: The prevalence of hypertension, diabetes and dyslipidemia was 27.8%, 5.9% and 48.3%, respectively. Despite the high prevalence of dyslipidemia, the subjects'awareness of it and its treatment rates were the lowest, which resulted in a low control rate. Of the 288 subjects, 158 (55%) had at least one of the three conditions. The prevalence of the combination of cardiovascular risk factors increased with age, and 32.7% of those aged 60 or older had two or three of the cardiovascular risk factors. Combinations of cardiovascular risk factors were significantly related with severe pain and fatigue. Conclusion: Cardiovascular risk factors were highly prevalent among the women with rheumatoid arthritis, but the rates of awareness, treatment, and control were suboptimal. There is a pressing need to facilitate the prevention, early detection and appropriate management of hypertension, diabetes and dyslipidemia among patients with rheumatoid arthritis in order to prevent cardiovascular disease.

• Steel and Composite Structures
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• 제30권5호
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• pp.483-492
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• 2019

In the current study, the influence of the initial lateral (sweep) shape and the cross-sectional twist imperfection on the lateral torsional buckling (LTB) response of doubly-symmetric steel I-beams was investigated. The material imperfection (residual stress) was not considered. For this objective, standard European IPN 300 beam with different unbraced span was numerically analyzed for three imperfection cases: (i) no sweep and no twist (perfect); (ii) three different shapes of global sweep (half-sine, full-sine and full-parabola between the end supports); and (iii) the combination of three different sweeps with initial sinusoidal twist along the beam. The first comparison was done between the results of numerical analyses (FEM) and both a theoretical solution and the code lateral torsional buckling formulations (EC3 and AISC-LRFD). These results with no imperfection effects were then separately compared with three different shapes of global sweep and the presence of initial twist in these sweep shapes. Besides, the effects of the shapes of initial global sweep and the inclusion of sinusoidal twist on the critical buckling load of the beams were investigated to unveil which parameter was considerably effective on LTB response. The most compatible outcomes for the perfect beams was obtained from the AISC-LRFD formulation; however, the EC-3 formulation estimated the $P_{cr}$ load conservatively. The high difference from the EC-3 formulation was predicted to directly originate from the initial imperfection reduction factor and high safety factor in its formulation. Due to no consideration of geometric imperfection in the AISC-LFRD code solution and the theoretical formulation, the need to develop a practical imperfection reduction factor for AISC-LRFD and theoretical formulation was underlined. Initial imperfections were obtained to be more influential on the buckling load, as the unbraced length of a beam approached to the elastic limit unbraced length ($L_r$). Mode-compatible initial imperfection shapes should be taken into account in the design and analysis stages of the I-beam to properly estimate the geometric imperfection influence on the $P_{cr}$ load. Sweep and sweep-twist imperfections led to 10% and 15% decrease in the $P_{cr}$ load, respectively, thus; well-estimated sweep and twist imperfections should considered in the LTB of doubly-symmetric steel I-beams.

• 디지털융복합연구
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• 제19권1호
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• pp.89-97
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• 2021

연구 목적은 조직원의 정보보안 관련 조직시민행동과 연관되는 인지과정의 영향관계를 검증하는 것이다. 연구방법은 개인의 전망차원(이익, 손실)과 조직의 목표지향성 차원(성취지향, 안정지향)의 교차설계를 실시하고, 정보보안인지요인은 분배공정성, 대처효능감, 자기효능감, 그리고 조직시민행동으로 구성하였다. 연구결과 전망차원은 대처효능감과 자기효능감에 유의미한 영향을 미치고 있었으며, 이익의 영향력이 손실보다 높은 것으로 나타났다. 목표지향성은 대처효능감과 자기효능감에 유의미한 영향을 미치고 있었으며, 성취지향의 영향력이 안전지향보다 높은 것으로 나타났다. 정보보안 요인간의 관계를 설명한 연구모형은 분배공정성, 대처효능감, 조직시민행동간의 부분매개모형으로 검증되었다. 연구의 시사점은 개인 의사결정 요인과 조직 문화 요인을 복합적으로 고려하여 정보보안 전략 수립을 하는 것이 필요함을 제시한다.

• The Korean Journal of Pain
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• 제34권2호
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• pp.241-245
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• 2021

Background: It has been reported that a new type of headache may develop as a result of face mask use during the COVID-19 pandemic. The aim of this study is to investigate the clinical features of face mask-related headache during the COVID-19 pandemic. Methods: This is a cross-sectional study carried out on healthcare workers at the Afyonkarahisar Health Sciences University. The number of workers at our university was established. Sample size was calculated using the G*Power program. A questionnaire consisting of questions relating to pre-existing headache, an aggravation in headache, and de-novo headache was filled out by 3 neurologists with all participants. Results: Data was collected from a total of 375 participants, after the exclusion of 5 individuals who refused to participate. Out of all participants, 26 (6.9%) used a filtering mask, 274 (73.1%) used a surgical mask, 75 (20.0%) participants used a combination of both masks. The number of participants with preexisting headache was 114 (30.4%) had pre-existing headache. Of those with pre-existing headache, 77 (67.5%) healthcare workers had reported an aggravation in their headache after mask use. De-novo headache was observed in 116 (30.9%) of participants. De-novo headache characteristics included throbbing in 17 (14.7%) participants and pressing in 99 (85.3%) participants. In addition, symptoms such as tachypnea, sleep disturbance, and fatigue were found to be significantly higher. Conclusions: This study indicates that healthcare workers develop headaches due to use of masks during the COVID-19 outbreak.

• Journal of Forest and Environmental Science
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• 제37권4호
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• pp.309-314
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• 2021

This study aimed to enhance seed productivity and secure genetic resources for Pinus densiflora for. multicaulis. We analyzed the characteristics of cone and seed generated by control pollination between Pinus densiflora (PD) and Pinus densiflora for. multicaulis (PDM). The highest number of cone scales (63.0) was obtained from the self-pollinated (sp) PDM clone B (PDM-sp-B), whereas the lowest number of cone scales (44.7) was obtained from two combinations designated as PDM-A×PD-075 and PDM-A×PD-0111. Both female parents of the hybrids were PDM-A. The highest seed production capacity (80.8) was obtained from the open-pollinated (op) PDM clone B (PDM-op-B). The seed potentials of PDM-B×PD-0111, PDM-op-A, and PDM-sp-B were 67.4, 66.5, and 63.1, respectively. The highest number of fertile scales (41.5) was obtained from PDM-op-B, and the lowest number of fertile scales (28.8) was obtained from PDM-A×PD-075. The total number of aborted ovules and 1st aborted ovules was not statistically significant in the mating design. The cross combination of PDM-B×PD-0111 had the highest number (34.8) of filled seeds and the lowest number of 2nd aborted ovules (5.2) and empty seeds (9). PDM-op-B had the highest number of developed seeds (47.6), although the number of empty seeds was the highest (41.2). Therefore, we conclude that the mating design of PDM-B×PD-0111 is useful for future breeding programs to improve seed yield of PDM. Our results showed that there was a strong correlation between the following two parameter pairs: number of scales and number of fertile scales, and the number of fertility scales and seeds potential (r=0.89 and r=0.84, respectively; both p<0.01).