Background: Recent research suggests that the most effective and proactive method for correcting excessive pronation, which contributes to the lowering of the medial longitudinal arch, is to enhance both intrinsic and extrinsic foot muscles simultaneously. Objectives: This study aims to compare the effects of intrinsic and extrinsic foot muscle exercises on medial longitudinal arch height, plantar pressure distribution, and lactate levels in university students with flexible flatfoot. Design: Randomized controlled trial study. Methods: Twenty-two students with flexible flat foot participated in this study and were recruited by N University in Korea. The subjects were randomly divided into Intrinsic foot muscle strengthening group (IFG; n=11) that went through Intrinsic foot muscle strengthening exercise, Extrinsic foot muscle strengthening group (EFG; n=11) that went through extrinsic foot muscle strengthening exercise. SPSS was used for statistical analysis. Results: Both groups showed significant increases in medial arch height and first metatarsal bone pressure, while EFG also had increased pressure at the second to fourth metatarsal bones. No significant differences were found in lactate levels. Conclusion: Both intrinsic and extrinsic foot muscle strengthening exercises can be suggested as effective interventions for improving medial longitudinal arch height and plantar pressure.

The swelling capacity of bentonite buffers is vital in high-level radioactive waste (HLW) repositories, as it minimizes groundwater infiltration, prevents nuclides from reaching the biosphere, and stabilizes the HLW canisters. As swelling capacity is a function of temperature, understanding bentonite’s behavior at approximately 100°C (its presumed upper limit) is essential. However, research on this subject has been scarce. Hence, this study explored the effects of thermal treatment of Ca-bentonite at 105°C under injected water pressures. The results suggest a 19% reduction in “swell index” and a 35%–36% decrease in the total pressure in thermally treated bentonite. The heated samples demonstrated higher hydraulic conductivity than the non-heated ones, indicating potential performance deterioration in controlling the fluid movement. Furthermore, the injected water pressure (base pressure) was not fully transmitted to the sample owing to the difference between the base and back pressures, leading to variations in the total pressure despite maintaining a constant differential pressure. Thus, the results demonstrated a degradation in bentonite’s swelling capacity and its compromised role in safe HLW disposal, when subjected to treatment at 105°C. The insights from this research can assist in HLW repository design, while highlighting the need for further research into bentonite’s performance.

Damage to masonry walls can occur for various factors. It is often believed that heavy rains and increased rainfall cause soil and sand to flow into the stone masonry walls, leading to this damage. However, no research has definitively proven or analyzed this causal relationship.This study aims to evaluate the causes of damage to masonry walls due to severe rainfall and to propose preventive strategies to mitigate future risks. The assessment found that, as a form of cultural heritage, the stone masonry walls did not exhibit any structural or material issues that could compromise their stability. However, concerns were raised about potential problems arising from hydraulic pressure due to rising groundwater levels. Calculations and computer simulations confirmed that the risk of collapse increases with higher groundwater levels. Therefore, it is essential to carry out repairs and reinforcements to prevent a recurrence of this situation.

이 연구는 다목적 선박(MPV)의 공기역학적 구조물 설계, 분석 및 향상을 통해 그린 워터 압력에 의한 구조적 안전을 보장하고, 탈탄소화 및 에너지 효율성에 이바지하는 방법을 기술하였다. 유한 요소 분석(FEA)을 통한 초기 평가에서 좌굴 발생에 대한 잠재적인 취약점 이 있음을 확인하였다. 이러한 문제를 해결하기 위해 보강재(Carling stiffener)와 두께 증가를 통하여 응력을 재분배하고 국부적인 좌굴 발생의 위험을 최소화하였다. 보강 후 분석 결과, 한국선급(KR)의 안전 기준인 항복 강도, 미국 선급(ABS) 좌굴 강도 및 노르웨이 표준(NORSOK) 변 위 기준을 모두 충족하는 것이 확인되었다. 결과적으로 고유치 좌굴 해석 결과가 안전 기준을 초과하고 최대 변위가 허용 한계 내에 있는 등 중요한 개선이 이루어졌다. 이러한 개선은 극한의 해양 조건에서 운영 신뢰성을 보장할 수 있다. 이 연구는 공기역학적 항력 감소와 구조적 안전성의 이중적인 이점을 강조하며, 국제 해사 기구(IMO)의 2050 탈탄소화 목표에 부합하는 연료 효율성 및 온실가스 배출 감소에 이바지할 수 있다. 연구 결과는 다양한 선박 유형에 걸쳐 항력 감소 기술을 확장하기 위한 기초 자료를 제공하며, 지속 가능하고 탄력적인 해양 운영을 위한 대안을 제시하였다. 향후 연구는 구조적 안전 평가를 가속할 수 있는 단순화된 모델링 기술 개발에 집중할 것이다.

Background: Hallux valgus (HV) is a common foot deformity in which the great toe deviates laterally and the first metatarsal deviates medially, leading to pain, discomfort, and reduced mobility. HV severity is typically assessed using the hallux valgus angle (HVA) and intermetatarsal angle (IMA). Objects: This study aimed to explore how changes in skeletal, muscular, and functional variables correlate with HV severity and to provide evidence for more integrated treatment approaches. Methods: Sixty volunteers with mild to moderate bilateral HV (HVA 15–40 degrees) participated. The measurements included HVA and IMA via radiography, abductor hallucis muscle (AbdH) cross-sectional area (CSA) and tone using ultrasound and Myoton PRO, range of motion (ROM) of the ankle and great toe metatarsophalangeal (MTP) joint with a goniometer, and plantar pressure during gait with a Zebris FDM system. Pearson’s correlation coefficient was used for the statistical analysis. Results: An Increased HVA was associated with a higher IMA (r = 0.858, p < 0.05). The HVA was inversely related to the AbdH CSA (r = –0.337, p < 0.05) and muscle tone (r = –0.889, p < 0.01). With increasing HVA, dorsiflexion ROM of the ankle (r = –0.307, p < 0.01) and both flexion (r = –0.197, p < 0.05) and extension (r=-0.182, p<0.05) ROM of the great toe MTP joint decreased. Conversely, ankle plantar flexion ROM increased with the HVA (r = 0.312, p < 0.01). Additionally, plantar pressure increased in the second metatarsal areas (r = 0.457, p < 0.05) a with higher HVA. Conclusion: This study demonstrates significant correlations between HV severity and various biomechanical factors, highlighting the need for comprehensive treatment strategies. While stretching the adductor hallucis muscle and strengthening the AbdH have been widely recognized interventions for HV, our findings provide evidence that ROM exercises for the ankle and the MTP joint of the great toe are also critical components of a physical therapy program for managing HV. Longitudinal studies are required to assess the effectiveness of these approaches.

In this study, in order to develop an eco-friendly filtration method that considers the health and safety of the aquatic ecosystem by differentiating it from chemical methods (coagulants, oxidants, etc.), which are mainly used as methods for managing the removal of algae in the algal bloom stage, an effective separation membrane for algae removal was reviewed, an appropriate technology was proposed through field application, and the effect of algae removal was evaluated. The membrane used was applied in the field by constructing an optimal technology through auxiliary facilities with an immersion tubular membrane and a pressurized tubular membrane resistant to adhesive pollutants and algae. As a result, the strong characteristics of Fouling (blocking) by adhesive algae were confirmed, and the effect of removing algae and particulate matter in the immersion type tubular membrane was 99% chlorophyll-a (Chl-a), 99.2% suspended solid (SS), and 96.7% of pressurized tubular membranes, showing excellent effects in removing algae and particulate organic matter. In addition, as a result of field application to eutrophic reservoirs where high-density algae are distributed, it was confirmed that stable operation of algae was possible during the process of filtering, separation, and concentration.

In this study, the time to endure after conducting a test pressure test was analyzed according to the hose development length of the household hose reel indoor fire hydrant according to the apartment area. First, when the household area is 50㎡, a household hose reel indoor fire hydrant is installed inside the bathroom, and the hose is bent in a circular shape to the farthest fire point, and the test pressure is found to be inadequate only when the hose development length is 5m. When the household area of an apartment is 84㎡. It was found that the test pressure was inappropriate only when the hose deployment length was 5m with the hose bent in a circular shape to the farthest point by installing a household hose reel indoor fire hydrant inside the bathroom. When the hose deployment length was 15m, the average experimental value was 3.9 Mpa and the water pressure resistance time was 8 min. It was found that the test pressure and holding time were suitable for all of the working pressure of 0.7 Mpa, the inner diameter of the hose 25mm and 32mm, and the hose deployment length. When the installation of the hose reel indoor fire hydrant hose was 3 Mpa, the internal diameter of the hose was 25mm, 32mm, and the length of the hose deployment were all suitable.

본 연구는 거래적 스트레스 이론과 접근-회피적 틀에 근거하여, 성과 압박이 주도적 행동에 미치는 영향을 설명하는 인지-심리적 기제를 연구하였다. 구체적으로, 접근적 틀에서 성과 압박이 도전으로 평가 될 경우 역할 확장 자기 효능감이 증가하여 주도적 행동을 촉진하는 반면, 회피적 틀에서 성과 압박이 위협으로 평가될 경우 역할 확장 자기 효능감이 감소하여 주도적 행동이 저하되는지를 규명하고자 하였 다. 본 연구는 중국 기업의 다양한 분야에 종사하는 종업원들을 대상으로 온라인 자기보고식 설문 조사를 실시하였으며, 불성실한 응답을 제거한 후 총 369부의 설문지를 분석에 사용하였다. 분석 결과, 성과 압박은 도전 및 위협 평가 모두와 정의 관계가 있는 것으로 나타났다. 성과 압박이 도전으로 평가된 경우, 역할 확장 자기 효능감이 증가하는 반면 성과 압박이 위협으로 평가된 경우, 역할 확장 자기효능감이 감소하는 것으로 나타났으며, 역할 확장 자기효능감은 주도적 행동과 정의 관계가 있 는 것으로 나타났다. 또한 성과 압박이 주도적 행동에 미치는 과정에서 도전 평가와 역할 확장 자기 효능 감은 다중 직렬 매개 역할을 하는 것으로 나타났으나, 위협 평가와 역할 확장 자기 효능감은 성과 압박과 주도적 행동 간의 관계를 매개하지 않는 것으로 밝혀졌다. 본 연구는 성과 압박이 주도적 행동에 미치는 긍정적 및 부정적 영향을 설명하는 인지-심리적 기제를 제시함으로써 기존 연구를 확장하고, 이를 통해 실무적 시사점을 제공하는 데 기여하고자 한다.

이 연구는 중학교 과학 교육과정이 중학생들의 기압 작용 방향에 대한 개념 변화에 어떤 영향을 미쳤는지를 조 사하였다. 이를 위해 중학교 1학년과 3학년의 기압 관련 학습 내용을 토대로 구성된 개념 검사지를 중학교 3학년 학생 들을 대상으로 실시하였다. 분석 결과, 중학교 1학년 과학 1에서 학습한 용기 내 분자 운동과 관련된 기압의 개념과 작 용 방향에 대해 비교적 정확한 개념을 갖고 있음에도 불구하고, 중학교 3학년 과학 3에서 토리첼리 실험을 학습하면서 기압의 작용 방향이 아래쪽으로 향한다는 오개념을 갖게 되는 경우가 많음을 확인하였다. 이는 교육과정 및 교과서 내 용의 구성 방식이 학생들의 기압에 대한 개념 변화에 중요한 영향을 미칠 수 있음을 시사한다. 따라서 중학교 과학3 교과서에서 토리첼리 실험을 서술할 때, 기압을 단순히 무게의 관점이나 한 방향으로의 작용만을 강조하기 보다는 기압 이 모든 방향으로 작용할 수 있다는 과학 1의 개념을 다시 한번 명확히 할 필요가 있음을 제안한다. 이러한 노력은 학 생들의 과학적 개념의 내면화와 심화된 이해에 도움이 될 것으로 사료된다. 또한, 교수자들도 이러한 오개념을 사전에 인식하고 이를 고려하여 교수-학습 모형을 설계함으로써 학습자의 인지 갈등과 혼란을 선제적으로 최소화할 수 있을 것이다. 한편, 학습자의 오개념 및 교과서 분석 등에 관한 누적된 연구 결과가 교과서 내용에 반영될 수 있도록 책임 있는 기관의 체계적인 전략 및 지침 개발이 필요할 것이다.

The pressure sensor had been widely used to effectively monitor the flow status of the water distribution system for ensuring the reliable water supply to urban residents for providing the prompt response to potential issues such as burst and leakage. This study aims to present a method for evaluating the performance of pressure sensors in an existing water distribution system using transient data from a field pipeline system. The water distribution system in Y District, D Metropolitan City, was selected for this research. The pressure data was collected using low-accuracy pressure sensors, capturing two types of data: daily data with 1Hz and high-frequency recording data (200 Hz) according to specific transient events. The analysis of these data was grounded in the information theory, introducing entropy as a measure of the information content within the signal. This method makes it possible to evaluate the performance of pressure sensors, including identifying the most sensitive point from daily data and determining the possible errors in data collected from designated pressure sensors.

본 연구는 진단초음파 및 근적외선분광법 (NIRS)을 사용하여 발살바 조작 (VM)을 수행하기 위한 자발적인 흉강 내 압력 조정이 전전두엽 뇌기능 및 뇌혈류 역학의 변화에 미치는 영향을 조사하고자 하였다. 건강한 성인 16명을 대상으로 30과 40mmHg VM을 수행하고, NIRS를 통해 대뇌산소포화도 (rSO2)와 산화헤모글로빈 (HbO)을 측정하 였다. 그리고 진단초음파를 사용해 경동맥 (CCA)에서 최대혈류속도 (PSV)와 심박수 (HR)를 측정하고, 혈관경직도(STIFF)와 맥파전달속도 (PWV)를 도출하여 VM 수행 전후 차이를 비교하였다. 그 결과 30mmHg VM 수행 후 PSV 가 유의하게 증가하였고, PWV와 STIFF는 유의하게 감소하는 것으로 나타났다. 반면, 40mmHg에서는 HR의 유의한 감소만 나타났다. VM 수행 후 전전두엽의 뇌기능은 30과 40mmHg VM에서 rSO2가 증가하는 경향을 보였으나 유 의한 변화는 나타나지 않았다. 반면 HbO는 VM 수행 후 유의한 감소를 보여주었다. 결론적으로, 두 가지 강도의 흉강 내압에서 VM 수행은 뇌기능에 동일한 영향을 미치는 것으로 나타났으나, 흉강 내압이 높은 경우에는 체압이 높아 효과적인 혈관 이완이 나타나지 않았다. 반면, 낮은 흉강 내압에서는 혈관의 탄성도가 크게 증가되어 뇌혈관의 기능 개선에 효과적으로 작용할 수 있을 것으로 판단된다.

With the growth of silicon-based semiconductor sensors in the global sensor market, advancements in body motion detection for wearable devices and sustainable health monitoring have accelerated. This has led to a significant attention on various sensors with excellent flexibility and stretchability, such as PDMS, in numerous applications. In this study to adjust the sensitivity of conventional conductive pressure sensors, a porous sponge structure was initially created using a sugar template method. The polymer was prepared with four different ratios (5:1, 10:1, 20:1, 30:1) to achieve varying flexibilities. To ensure conductivity, the sponge was coated using a dip-coating method with a 3wt% CNT solution. The conductive sponges with various ratios were tested for sensitivity, demonstrating characteristics suitable for a wide range of pressure sensing applications.

The Climate chamber system is an essential facility for aerodynamic performance development of commercial vehicles to investigate air flow field characteristics in different climatic conditions. In particular, the analysis of airflow fields within the chamber system is an essential consideration for optimal design. In this study, the pressure characteristics and velocity uniformity in the test section area were predicted with blower impeller rotational speed using CFD. The velocity uniformity is affected by the distance from the blower nozzle outlet, reaching up to 72.7% at 695 RPM. The pressure differential between 300 RPM and 740 RPM shows an approximate difference of 2651 Pa, with a high-pressure distribution observed along the right side wall of the blower. These results are expected to be used as design data applicable for improving the performance of environmental chamber systems.

As the number of households with pets has increased worldwide, there is a growing trend of accepting pets as family members. Consequently, the pet food market has seen the emergence of concepts such as “human-grade,” “raw (PMR and BARF),” and “no synthetic additives” pet food. These concepts not only fulfill essential nutrients but also consider the health and habits of pets, a crucial aspect that should be at the forefront of our work. However, these types of pet food are prone to microbial contamination and component alterations caused by heat. Current studies and products have recently been developed overseas to apply non-thermal sterilization technologies to pet food commonly used in the food industry. In contrast, the domestic standards for non-thermal sterilization in pet food are insufficient. Therefore, a comprehensive review of non-thermal sterilization technologies, such as high-pressure processing (HPP), radiation, and plasma predominantly applied in the international pet food market, is deemed necessary. This review is expected to provide guidelines for non-thermal sterilization standards in domestic pet food, thereby laying the foundation for the safe production of raw pet food.

In this study, the characteristics of wind pressure distribution on circular retractable dome roofs with a low rise-to-span ratio were analyzed under various approaching flow conditions by obtaining and analyzing wind pressures under three different turbulent boundary layers. Compared to the results of previous studies with a rise-to-span ratio of 0.1, it was confirmed that a lower rise-to-span ratio increases the reattachment length of the separated approaching flow, thereby increasing the influence of negative pressure. Additionally, it was found that wind pressures varied significantly according to the characteristics of the turbulence intensity. Based on these experimental results, a model for peak net pressure coefficients for cladding design was proposed, considering variations in turbulence intensity and height.