Background: Stroke patients experience a variety of physical problems due to neurological problems, including difficulties with trunk control. Trunk taping is used to improve gait in stroke patients. Objectives: To investigated the immediate effect of thoracic and abdominal elastic taping on gait parameters (the dynamic balance and gait speed) in stroke patients. Design: Quasi experimental study. Methods: A total of 24 study subjects were randomly assigned to the experimental group (thoracic and abdominal taping, 12 people), and the control group (sham taping, 12 people). All subjects had timed up and go (TUG) test and 10 meter walk test (10MWT) measured before and after taping. Results: After taping, the TUG test and 10MWT results were significantly reduced only in the study group (P<.05). The TUG test and 10MWT results of the study group were significantly decreased compared to the control group. Conclusion: The thoracic and abdominal taping was found to improve trunk control in stroke patients, thereby improving dynamic balance and walking speed.

Background: Most non-pharmacological interventions for tension-type headache (TTH) focus on direct intervention in areas associated with headaches, with limited research exploring the indirect effects of interventions utilizing the fascia. Objectives: To investigate the effects of superficial back line (SBL) stretching and head-neck massage interventions on the range of motion (ROM) and neck disability index (NDI) of TTH. Design: Randomized controlled trial. Methods: The study participants were randomly allocated into three groups: SBL stretching group (n=9), head-neck massage group (n=9), and combined group (n=9). Prior to the intervention, measurements were taken for neck flexion ROM, straight leg raising test (SLRT) ROM, and NDI. The intervention consisted of 30-minute sessions conducted twice a week for 8 weeks. The second measurement took place 4 weeks after the intervention, followed by a third measurement conducted after an additional 4 weeks of intervention. Results: Comparing neck flexion ROM within each group, a significant increase was observed in the SBL stretching group after 8 weeks compared to before the intervention (P<.05). Regarding the comparison of SLRT ROM within each group, a significant increase was noted after 8 weeks compared to before the intervention in the SBL stretching, head-neck massage, and combined groups (P<.05). In terms of the comparison of NDI within each group, a significant decrease was observed in all three group after the intervention compared to before the intervention (P<.05). Conclusion: 8-week intervention involving SBL stretching, head-neck massage, and their combined application demonstrated effectiveness in improving neck flexion ROM, SLRT ROM, and the NDI for individuals with TTH.

Background: In community-dwelling elderly individuals, slower gait speed is closely related to the ground reaction force. In the elderly with fall experience, stride length and gait speed, and other gait parameters are closely related to gastrocnemius activation. Objectives: To investigate whether medial gastrocnemius stiffness influences gait parameters in community-dwelling elderly people who experienced falls. Design: Cross sectional study. Methods: A total of 149 community-dwelling older adults were assigned to the faller and non-faller groups. Gait parameters (step length, stride length, step width, cadence, heel and toe ground reaction force, heel and toe contact time), and stiffness of the medial and lateral gastrocnemius and tibialis anterior were measured using shear wave elastography. Results: Elderly fallers had shorter step and stride length, lower cadence and toe ground reaction force and heel contact time, and lower medial gastrocnemius stiffness than non-fallers. In elderly fallers, medial gastrocnemius stiffness was significantly correlated with step and stride length, step width, toe ground reaction force, and heel contact time. Conclusions: Lower medial gastrocnemius stiffness in the elderly fallers decreases gait parameters, which can be a risk factor for falls. Therefore, medial gastrocnemius stiffness is a major factor that may associated gait parameters that can determine the risk of fall in community-dwelling elderly individuals.

Background: Problem-based learning (PBL) is presented as a superior teaching method compared to existing lecture-based learning. Objectives: To analyzed the effectiveness of creative problem-solving competency, class participation, and self-efficacy in physical therapy students after PBL. Design: Questionnaire design. Methods: This study involved 29 physical therapy students and analyzed changes in their creative problem-solving competency, class participation, and self-efficacy and the correlations between these measurement variables before and after PBL on the “Therapeutic Exercise & Practice” subject. Results: PBL in the musculoskeletal exercise therapy-related subject significantly improved class participation and self-efficacy (P<.05) compared to conventional lecture-based learning, but there was no significant difference in creative problem-solving competency. There was also a positive correlation between a higher level of class participation and higher self-efficacy (P<.05). Conclusions: PBL in the “Therapeutic Exercise & Practice” subject in the Department of Physical Therapy can be an effective educational strategy to increase students’ class participation and self-efficacy. Accordingly, instructors in this department should systematically construct the design of PBL curricula to improve the quality of educational content.

Background: This study investigated quadriceps femoris muscle activity by comparing concentric and eccentric contractions with self-selective squat speed. Objectives: Study participants agreed in advance and included 30 male college students in their 20s without musculoskeletal system disease. Design: A randomized controlled trial. Methods: Participants who participated in this study agreed in advance and recruited 30 male college students in their 20s who had no disease with musculoskeletal system to conduct this study. When squatting at a self-selected speed, the subjects were evaluated using one-way ANOVA to compare concentric and eccentric contraction muscle activity. Results: There were significant differences between the rectus femoris, vastus medialis, and vastus lateralis regarding concentric contractions.contractions. There was a significant difference in vastus medialis but no significant difference between rectus femoris and vastus lateralis for eccentric contractions. Conclusion: During concentric contraction, all muscles and eccentric contractions indicated significant improvement in the vastus medialis. Therefore, to minimize knee joint injury and maximize efficient muscle activity, self-selected slow and moderate speeds based on self-selection speed when performing the sit-down motion during a squat and moderate speed with fast motions when performing the standing motion should be considered as high muscle activities.

Background: The Nordic hamstring exercise is effective as a representative exercise for strengthening eccentric contraction that can activate the hamstring at high levels, improve eccentric contraction strength and ability, and significantly reduce injury rates. Objectives: To investigated a comparison with the lunge exercise to determine the effect of the Nordic hamstring exercise on muscle activity and balance ability in a sample of adult amateurs and football players. Design: Randomized controlled trials. Methods: The subjects of the study were stratified samples of 28 professional and amateur football players and two groups (Nordic hamstring group and lunge group) of 14 people each were studied. Surface electromyography using, was performed to measure the hamstring muscle activity, and the good morning exercise was selected as the measurement exercise. For balance ability, the surface area ellipse and length were measured with BioRescue, while for static balance, the posture of closing the eyes and single-limb standing was measured, and for dynamic balance the one-legged squat was measured. Results: The %MVIC of the semitendinosus and the biceps femoris improved in the Nordic hamstring exercise group and showed statistically significant increase (P<.05). The static and dynamic balance improved in the Nordic hamstring exercise group and showed statistically significant decrease (P<.05). Conclusion: The Nordic hamstring exercise can be useful as an exercise to improve the hamstring muscle activity and balance ability of professional and amateur football players.

Background: Hemiparesis not only affects the affected side but also exerts an impact on the unaffected side. Stroke patients endure muscular weakness attributable to hemiparesis, resulting in asymmetry of muscular strength between the paralyzed and non-paralyzed sides. Objectives: To investigate the correlation between lower limb muscle strength asymmetry and functional factors in patients with stroke. Design: A cross-sectional study. Methods: A total of 58 stroke patients participated in this study. After measuring the muscle strength of both lower limbs using manual muscle testing, the asymmetry was calculated. Functional factors such as berg balance scale (BBS), timed up and go (TUG), 10-metre walk (10MW), and modified barthel index (MBI) were measured. Results: The BBS showed positive correlations with hip, knee, and ankle strength asymmetry (P<.05). The TUG showed negative correlations with hip, knee, and ankle strength asymmetry (P<.05). The 10MW showed negative correlations with hip, knee, and ankle strength asymmetry (P<.05). The MBI showed positive correlations only with hip strength asymmetry (P<.05). Conclusion: We were found that there is a more pronounced lower limb muscle strength asymmetry in the lower extremity of stroke patients, which is associated with BBS, TUG, and 10MW.

Background: Chronic back pain not only causes physical discomfort and decreased functionality but also affects emotional well-being, resulting in feelings of anxiety, depression, and other psychological issues. Studies have indicated that cognitive functional therapy and motor control exercises can alleviate chronic low back pain and associated psychological issues. Objectives: To investigated the effect of chronic low back pain on the cognitive functional therapy (CFT) and motor control exercises (MCE). Design: Quaxi-experimental study. Methods: Forty patients with chronic low back pain were randomly assigned and divided into 20 cognitive functional therapy group with motor control exercises group (CFTMG) and 20 patients in motor control exercises group (MCEG). After applying CFT with motor control exercises and motor control exercises for 8 weeks, changes in numeric pain rating scale (NPRS), Oswestry disability index (ODI) and Fear-avoidance beliefs questionnaire (FABQ) were observed. Results: In the CFTMG, statistically significant changes were observed in NPRS, ODI, and FABQ before and after the intervention. In the MCEG, statistically significant changes were observed in VAS and ODI before and after the intervention. Conclusion: The application of CFTM and MCE in patients suffering from chronic low back pain has demonstrated effectiveness in alleviating pain, enhancing back function, and reducing kinesiophobia associated with the condition.

Background: The Nordic hamstring exercise is a closed-chain exercise that effectively activates all lower extremity muscles, but there is a lack of consideration of ankle joint which affects exercise effectiveness. One of the major advantages of the Nordic exercise have been known as strengthening lower extremity extensors. This manifests the exercise increases activities of the ankle plantar flexors as well as hip extensors. Objectives: To investigated the impacts of changes in ankle position on the lower extremity musculature and subjective difficulties during the Nordic hip extension exercise. Design: Cross-sectional study. Methods: Twenty the healthy male participants participated in this study. Participants perform three variations of the Nordic exercises including three ankle positions. Each Nordic exercise was defined as ankle position (neutral, dorsiflexion and plantar flexion). During the Nordic exercise, erector spine (ES), gluteus maximus (GM), biceps femoris (BF), gastrocnemius (GCM) activities and subjective difficulties (Borg RPE score) were measured. Results: Muscular activities of the biceps femoris and gastrocnemius were significantly different among the three ankle conditions, which showed controversial results (P<.05). The biceps femoris activity was significantly higher with the dorsiflexion condition, compared to the others (P<.05). On the other hand, activity of the gastrocnemius was significantly higher with the plantarflexion position compared to the others (P<.05). Conclusion: Present study suggests the ankle positional changes could affect lower muscular activities during the Nordic exercise. Although it is difficult to affirm the causes due to limited data, selective activation of the biceps femoris might accomplish with ankle dorsi flexion and that of the gastrocnemius might accomplish with the ankle plantarflexion during the Nordic exercises.

AA1050/AA6061/AA1050 layered sheet was fabricated by cold roll-bonding process and subsequently T4 and T6 aging-treated. Two commercial AA1050 sheets of 1 mm thickness and one AA6061 sheet of 2 mm thickness were stacked up so that an AA6061 sheet was located between two AA1050 sheets. After surface treatments such as degreasing and wire brushing, they were then roll-bonded to a thickness of 2 mm by cold rolling. The roll-bonded Al sheets were then processed by natural aging (T4) and artificial aging (T6) treatments. The as roll-bonded Al sheets showed a typical deformation structure, where the grains are elongated in the rolling direction. However, after the T4 and T6 aging treatments, the Al sheets had a recrystallized structure consisting of coarse grains in both the AA5052 and AA6061 regions with different grain sizes in each. In addition, the sheets showed an inhomogeneous hardness distribution in the thickness direction, with higher hardness in AA6061 than in AA1050 after the T4 and T6 age treatments. The tensile strength of the T6-treated specimen was higher than that of the T4-treated one. However, the strength-ductility balance was much better in the T4-treated specimen than the T6-treated one. The tensile properties of the Al sheets fabricated in the present study were compared with those in a previous study.

In this study, we designed and manufactured a large angular contact ball bearing (LACBB) with low deformation using JIS-SUJ2 steel and analyzed changes in its structural characteristics and chemical composition upon heat treatment. The bearing was produced by hot forging and heat treatment including a quenching and tempering (Q/T) process, and its properties were analyzed using 4 mm thick specimens. A difference in the size distribution of the carbide in the outer and inner parts of the bearing was observed and it was confirmed that large and non-uniform carbide was distributed in the inner part of the bearing. After heat treatment, the hardness value of the outer part increased from 13.4 HRC to 61 HRC and the inner part increased from 8.0 HRC to 59.7 HRC. As a result of X-ray diffraction (XRD) measurements, the volume fraction of the retained austenite contained in the outer part was calculated to be 3.5~4.8 % and the inner part was calculated to be 3.6~5.0 %. The surface chemical composition and the content of chemical bonds were quantified through X-ray photoelectron spectroscopy (XPS), and a decrease in C=C bonds and an increase in Fe-C bonds were confirmed.

In zinc-air batteries, the gel polymer electrolyte (GPE) is an important factor for improving performance. The rigid physical properties of polyvinyl alcohol reduce ionic conductivity, which degrades the performance of the batteries. Zinc acetate is an effective additive that can increase ionic conductivity by weakening the bonding structure of polyvinyl alcohol. In this study, polymer electrolytes were prepared by mixing polyvinyl alcohol and zinc acetate dihydride. The material properties of the prepared polymer electrolytes were analyzed by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Also, Electrochemical impedance spectroscopy was used to calculate ionic conductivity. The electrolyte resistances of GPE, 0.2 GPE, 0.4 GPE, and 0.6 GPE were 0.394, 0.338, 0.290, and 0.213 Ω, respectively. In addition, 0.6 GPE delivered 0.023 S/cm high ionic conductivity. Among all of the polymer electrolytes tested, 0.6 GPE showed enhanced cycle life performance and the highest specific discharge capacity of 11.73 mAh/cm2 at 10 mA. These results verified that 0.6 GPE improves the performance of zinc-air batteries.

The sintering shrinkage behaviors of low temperature cofired ceramics (LTCC) and resistors were compared using commercial LTCC and thick-film resistor pastes, and factors influencing the camber of cofired resistor/LTCC bi-layers were also investigated. The onset of sintering shrinkage of the resistor occurred earlier than that of LTCC in all resistors, but the end of sintering shrinkage of the resistor occurred earlier or later than that of LTCC depending on the composition of the resistor. The sintering shrinkage end temperature and the sintering shrinkage temperature interval of the resistor increased as the RuO2/glass volume ratio of the resistor increased. The camber of cofired resistor/LTCC bi-layers was obtained using three different methods, all of which showed nearly identical trends. The camber of cofired resistor/LTCC bi-layers was not affected by either the difference in linear shrinkage strain after sintering between LTCC and resistors or the similarity of sintering shrinkage temperature ranges of LTCC and resistors. However, it was strongly affected by the RuO2/glass volume ratio of the resistor. The content of Ag and Pd had no effect on the sintering shrinkage end temperature or sintering shrinkage temperature interval of the resistor, or on the camber of cofired resistor/LTCC bi-layers.

The theoretical capacity of silicon-based anode materials is more than 10 times higher than the capacity of graphite, so silicon can be used as an alternative to graphite anode materials. However, silicon has a much higher contraction and expansion rate due to lithiation of the anode material during the charge and discharge processes, compared to graphite anode materials, resulting in the pulverization of silicon particles during repeated charge and discharge. To compensate for the above issues, there is a growing interest in SiOx materials with a silica or carbon coating to minimize the expansion of the silicon. In this study, spherical silica (SiO2) was synthesized using TEOS as a starting material for the fabrication of such SiOx through heating in a reduction atmosphere. SiOx powder was produced by adding PVA as a carbon source and inducing the reduction of silica by the carbothermal reduction method. The ratio of TEOS to distilled water, the stirring time, and the amount of PVA added were adjusted to induce size and morphology, resulting in uniform nanosized spherical silica particles. For the reduction of the spherical monodisperse silica particles, a nitrogen gas atmosphere mixed with 5 % hydrogen was applied, and oxygen atoms in the silica were selectively removed by the carbothermal reduction method. The produced SiOx powder was characterized by FE-SEM to examine the morphology and size changes of the particles, and XPS and FT-IR were used to examine the x value (O/Si ratio) of the synthesized SiOx.

β-Ga2O3 has become the focus of considerable attention as an ultra-wide bandgap semiconductor following the successful development of bulk single crystals using the melt growth method. Accordingly, homoepitaxy studies, where the interface between the substrate and the epilayer is not problematic, have become mainstream and many results have been published. However, because the cost of homo-substrates is high, research is still mainly at the laboratory level and has not yet been scaled up to commercialization. To overcome this problem, many researchers are trying to grow high quality Ga2O3 epilayers on hetero-substrates. We used diluted SiH4 gas to control the doping concentration during the heteroepitaxial growth of β-Ga2O3 on c-plane sapphire using metal organic chemical vapor deposition (MOCVD). Despite the high level of defect density inside the grown β-Ga2O3 epilayer due to the aggregation of random rotated domains, the carrier concentration could be controlled from 1 × 1019 to 1 × 1016 cm-3 by diluting the SiH4 gas concentration. This study indicates that β-Ga2O3 hetero-epitaxy has similar potential to homo-epitaxy and is expected to accelerate the commercialization of β-Ga2O3 applications with the advantage of low substrate cost.

1976년에 제정된 미국의 외국주권면제법은 외국정부의 주권적, 공법적 행위에 대해서는 미국법원은 원칙적으로 재판관할이 없음을 표명하면서, 예외적으로 그 외 국정부의 행위가 해당 주권면제법에서 규정하는 예외(exception)에 해당할 경우, 미국법원의 외국정부에 대한 재판관할을 인정한다. 특히“테러행위 예외(terrorism exception)”규정은 1996년에 외국주권면제법에 처음으로 추가되었으며, 외국 정부가 테러행위를 지원하여, 미국의 국무부로부터 “테러지원국”으로 지정된 국가의 경우, 해당 테러행위로 인해 신체적, 정신적 손해 를 입은 피해자들은 해당 테러지원국에 대해 민사상 책임을 묻는 민사소송을 미국 법원에서 제기할 수 있다. 본 논문에서는 외국주권면제법 상의 테러행위 예외 규정과 1996년 제정 이후 개 정된 내용을 살펴보고, 법원에서 관련 내용을 어떻게 적용했는지를 검토한다. 특히 테러행위 예외규정을 해당 규정이 제정 또는 개정되기 이전의 테러행위에도 소급 적으로 적용할 수 있는지? 피해자들에게 징벌적 손해배상도 부여할 수 있는지? 또 한 미국법원에서 테러지원국의 민사상 손해배상 판결을 획득한 피해자들이 테러지 원국의 재산을 압류 또는 집행할 때의 문제점 등을 거론한 판례도 살펴본다. 추가 적으로 북한에 대해 테러행위 예외를 적용하여, 북한의 재산을 압류, 집행한 오토 웜비어(Otto Warmbier) 관련 판결, 이란의 미국 내 재산압류에 대한 미국 판결 등을 분석한다.

BaTiO3-Poly vinylidene fluoride (PVDF) solution was prepared by adding 0~25 wt% BaTiO3 nanopowder and 10 wt% PVDF powder in solvent. BaTiO3-PVDF film was fabricated by spreading the solution on a glass with a doctor blade. The output performance increased with increasing BaTiO3 concentration. When the BaTiO3 concentration was 20 wt%, the output voltage and current were 4.98 V and 1.03 μA at an applied force of 100 N. However, they decreased when the over 20 wt% BaTiO3 powder was added, due to the aggregation of particles. To enhance the output performance, the generator was poled with an electric field of 150~250 kV/cm at 100 °C for 12 h. The output performance increased with increasing electric field. The output voltage and current were 7.87 V and 2.5 μA when poled with a 200 kV/cm electric field. This result seems likely to be caused by the c-axis alignment of the BaTiO3 after poling treatment. XRD patterns of the poled BaTiO3-PVDF films showed that the intensity of the (002) peak increased under high electric field. However, when the generator was poled with 250 kV/cm, the output performance of the generator degraded due to breakdown of the BaTiO3-PVDF film. When the generator was matched with 800 Ω resistance, the power density of the generator reached 1.74 mW/m2. The generator was able to charge a 10 μF capacitor up to 1.11 V and turn on 10 red LEDs.

Amorphous In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs) with a coplanar structure were fabricated to investigate the feasibility of their potential application in large size organic light emitting diodes (OLEDs). Drain currents, used as functions of the gate voltages for the TFTs, showed the output currents had slight differences in the saturation region, just as the output currents of the etch stopper TFTs did. The maximum difference in the threshold voltages of the In-Ga-Zn-O (a-IGZO) TFTs was as small as approximately 0.57 V. After the application of a positive bias voltage stress for 50,000 s, the values of the threshold voltage of the coplanar structure TFTs were only slightly shifted, by 0.18 V, indicative of their stability. The coplanar structure TFTs were embedded in OLEDs and exhibited a maximum luminance as large as 500 nits, and their color gamut satisfied 99 % of the digital cinema initiatives, confirming their suitability for large size and high resolution OLEDs. Further, the image density of large-size OLEDs embedded with the coplanar structure TFTs was significantly enhanced compared with OLEDs embedded with conventional TFTs.

This comprehensive study delves into the intricate process of exfoliating and functionalizing boron nitride nanosheets (BNNSs) extracted from hexagonal boron nitride (h-BN), and meticulously explores their potential application within epoxy composites. The extensive research methodology encompasses a sequence of treatments involving hydrothermal and sonication processes aimed at augmenting the dispersion of BNNSs in solvents. Leveraging advanced analytical techniques such as Raman spectroscopy, X-ray diffraction, and FTIR spectroscopy, the study rigorously analyzes a spectrum of changes in the BNNS’s properties, including layer count variations, interlayer interactions, crystal structure modifications, and the introduction of functional groups. The research also rigorously evaluates the impact of integrating BNNSs, specifically glycidyl methacrylate (GMA)-functionalized BNNSs, on the thermal conductivity of epoxy composites. The conclusive findings exhibit notable enhancements in thermal properties, predominantly attributed to the enhanced dispersion of fillers and enhanced interactions within the epoxy matrix. This pioneering work illuminates the wide potential of functionalized BNNSs for significantly enhancing the thermal conductivity of epoxy composites, paving the way for advanced materials engineering and practical applications.

최근 해외 주요 정보선진국들 차원에서 국가안보의 위협에 대한 인식들의 변화가 발견된다. 전통적인 국가안보의 위협이었던, WMD, 적국 스파이행 위, 군사도발, 테러리스트ㆍ초국가 범죄단체의 위협들 외에도 기후변화, 전 염병과 신종바이러스의 위협, 식량과 반도체 등 공급망, 사이버 공격, 신 기술과 관련된 경쟁과 악용에 대한 위협들이 새롭게 인식되고 있다. 무엇 보다 악의적 허위정보, 정보조작을 통한 사회혼란, 여론조작, 선거개입 등 의 민주주의 시스템을 흔드는 시도들은 자유민주주의 국가에 대한 중요한 위해요소로 등장하였다. 이 같은 위협들이 실존적인 인류와 국가의 생존과 관련되면서 해외주요 국가들은 정보기관들에 복합적 국가안보위협에 대응 하기 위해 기술적, 지식적, 인지적 준비를 갖출 것을 요구하고 있다. 이를 위해서는 입법을 통한 정보기관 권한 강화하가 가장 중요하다. 그러나 국 내의 경우 정보기관의 수사 및 정보활동을 더 약화되었고 현재 주요 국내 정보기관의 활동은 해외의 정보강국들에 비해 상대적으로 크게 위축된 상 황이다. 반면, 미국 등 서구 주요 정보선진국들은 새로운 안보위협들에 대 응할 수 있도록 정보기관의 활동과 권한을 강화할 입법조치를 취하고 있 다. 이러한 변화는 신냉전 상황에서 각 국가의 핵심적인 안보전략과 정보 기관의 업무범위와 방향을 일치시키고 조율하는 것으로 향후 수년간 이러 한 추세가 지속될 것이 예측된다. 따라서 주요 정보강국들의 정보기관 활 동과 권한을 규정하는 법률들을 이해하는 것은 오늘날 한국의 국가안보차 원의 정보활동에 중요하다. 그러나 국내에는 이와 같은 관점에서 정보활동 을 강화하는 법률에 대한 고찰연구를 발견하기 어렵다. 이에 따라 이 연구는 미국의 국가안보와 관련된 가장 핵심적 정보기관들의 정보활동, 업무, 권한과 이를 규정하는 법률들에 대해 소개하고자 한다. 이러한 연구의 목 적을 위해서 다양한 자료들을 대상으로 문헌분석을 수행하였다. 결론 부분 에서 미국 사례분석에 근거하여 국내 정보기관의 권한과 관련한 입법관련 정책시사점이 논의되었다.