Background: Chronic nonspecific low back pain (CNLBP) is a common musculoskeletal condition among middle-aged adults, often causing physical limitations and reduced quality of life. Transcutaneous electrical nerve stimulation (TENS) is a widely used non-pharmacological method for pain relief and muscle modulation. Objectives: To compare the effects of two high-frequency, high-intensity TENS protocols on pain, muscle tone, and stiffness in individuals with CNLBP. Design: Single-blinded, randomized controlled trial. Methods: Twenty-eight individuals with CNLBP were randomly assigned to an experimental group (EG) or control group (CG). Both received 60 Hz, highintensity TENS twice weekly for four weeks. Pain equivalent current (PEC), visual analogue scale (VAS), pain degree (PD), muscle tone (Hz), and stiffness (N/m) were measured pre- and post-intervention by a blinded assessor. Results: The EG showed significant improvements in all outcomes (P<.05), while the CG showed significant change only in VAS scores. Between-group analysis showed greater reductions in pain and muscle-related variables in the EG. Conclusion: The EG protocol, with individualized intensity adjustments and targeted stimulation sites, was more effective than the CG protocol in improving pain, muscle tone, and stiffness in adults with CNLBP.

본 연구는 저관리형 거리화단 화훼경관용 초화류 식물 선발을 위하여, 4종의 초본화훼식물(Zinnia elegans, Salvia splendens, Catharanthus roseus, Gomphrena globose )을 대상으로 무관 수 처리에 따른 내건성을 구명하고자 실시하였다. 4종 식물의 영구위조점을 알아본 결과, 무관수 후 백일초가 23일째 가장 먼저 고사하였고, 그 다음으로 살비아는 29일째, 일일초는 51일 째, 천일홍은 61일째에 고사하였다. 무관수 처리에 따른 4종의 용적수분함량 변화를 비교한 결과, 용적수분함량은 무관수 이후 지속적으로 감소하였고, 용적수분함량이 0%에 도달한 것은 백 일초가 무관수 16일째로 가장 빨랐으며, 그 다음으로 살비아 25일, 일일초 35일, 천일홍 40일 순으로 나타났다. 4종의 지상 부생체중의 감소율을 영구위조점에서 보았을 때 4종의 식물중 백일초의 감소율이 가장 높았고, 그 다음은 살비아, 천일홍, 일일초 순으로 높게 나타났다. 또한 지상부와 지하부 건물중의 증가율은 일일초가 가장 높았으며 통계적으로 유의하였다. 무관 수 처리에 따른 광합성 형광 변수 중 하나인 Fv/Fm 측정 결과, 백일초는 일시위조점인 15일째부터 감소하였고, 살비아는 무관 수 29일째, 일일초는 37일째, 천일홍은 43일째부터 감소하였 으며, 통계적으로 유의하였다. 무관수 처리에 따른 4종의 각 개체별 측정된 식생지수의 변화를 알아본 결과, 정규식생지수 (normalized difference vegetation index, NDVI), 광화학 반사율 지수(photochemical reflectance index, PRI), 안토 시아닌 반사율 지수(anthocyanin Reflectance Index, ARI) 가 무관수 기간동안 백일초, 살비아보다 일일초, 천일홍이 장기 간 건강한 잎의 범위에 속하였다. 본 연구결과를 종합해 볼 때, 저관리형 거리화단 화훼경관용 식물 선정 시 거리화단의 수분관 리 측면을 고려한다면 무관수 처리 후 약 50-60여 일간 생존하 여 내건성이 강한 것으로 나타난 일일초, 천일홍이 저관리형 거리화단 화훼경관 조성 시 적용 가능성이 매우 높은 식물로 판단되었다. 거리화단 화훼경관 조성 후 물관리가 어려운 거리 화단 화훼경관의 지속적인 유지, 관리에 대한 어려움이 부각되 어왔다. 따라서 저관리형 거리화단 화훼경관용 식물의 다양한 적용 및 관리를 위해서는 향후 보다 많은 식물종을 대상으로 한 실험뿐만 아니라 식물 내에서 품종 간의 비교에 대한 후속 연구도 필요한 것으로 생각되었다.

Purpose: This study aimed to develop and evaluate a simulation-based nursing education program for respiratory emergencies in critically ill, extremely low birth weight infants (ELBWIs). Methods: A single-arm quasi-experimental study was conducted with 32 neonatal intensive care unit (NICU) nurses. The program was developed systematically using the ADDIE model, incorporating needs assessment, real-case scenario development, and pilot testing. Data were collected before and after the intervention and were analyzed using paired and independent t-tests, as well as a one-way analysis of variance (ANOVA) with Scheffé post-hoc tests. Results: The results showed statistically significant improvements in participants’ problemsolving ability (t = -3.49, p = .001), clinical performance confidence (t = -4.64, p < .001), and overall clinical performance competency (t = -13.79, p < .001) following the training. The clinical relevance and feasibility of the program were supported by pilot testing and positive evaluations of the practicality and educational usefulness of the simulation scenarios. Conclusion: These findings suggest that the simulation-based program was effective in enhancing NICU nurses’ clinical competence in managing respiratory emergencies in ELBWIs and can be used as a practical alternative to traditional on-the-job training.

콩은 식물성 단백질과 지방을 얻기 위하여 가장 널리 재배되는 주요 콩과 작물이다. 그러나, 성숙 콩 실에는 가공적성과 품질 저하, 알러지 유발 및 소화 불량을 일으키는 성분이 포함되어져 있다. 콩 성숙 종실에서 주요 항영양성분으로 알려진 lectin, KTI, lipoxygenase 및 7S α' subunit의 4가지 단백질이 모두 부재하면서 stachyose의 함량이 낮은 대립 노란콩 ‘백세’ 품종이 국내 최초로 육성되었다. ‘백세’ 품종은 F-1-9와 F-1-6의 육성계통간 교배로 얻어진 집단에서 선발되었다. ‘백세’ 품종은 보라색 화색, 유한신육형, 회색 모용색 및 성숙시 연한 갈색의 협색을 가지며, 종피 및 제색은 노란색이다. ‘백세’의 종실 조단백질 및 조지방 함량은 각각 41.1%와 15.8%이었고, stachyose의 함량은 2.9 g/kg으로 대조 품종인 ‘대원’의 12.7 g/kg보다 훨씬 낮았다. ‘백세’는 콩 모자이크 바이러스, 콩 괴사병, 검은뿌리썩음병, 꼬투리 및 줄기 무름병, 불마름병에 대한 저항성을 나타내었다. ‘백세’는 6월 20일경 파종시 성숙기는 10월 16일경이며, 경장은 53 ㎝, 백립중은 31.0 g 정도이고 2020년 3곳에서의 평균 수량은 2.95 ton/ha-1 정도였다.‘백세’는 2023년 4월 6일 국립종자원에 콩 품종 등록(등록번호: 9515) 되었다.

This study presents the implementation of a direct power control (DPC) system based on virtual flux for an eco-friendly ship utilizing a low voltage DC distribution within a Simulink environment. The proposed system regulates the DC bus voltage and the instantaneous power of the generator. The electrical load of the generator is classified into three levels (low, medium, and high) and subjected to ±10% variations. Under these conditions, the characteristics of the DC bus voltage and current, instantaneous active and reactive power as well as the voltage and current of the generator, are thoroughly analyzed. The simulation results indicate that the DC bus voltage and instantaneous active and reactive power remain stable and well-regulated at their set-points despite load fluctuations. Furthermore, the voltage and current of the generator, consistently maintain sinusoidal waveforms and remain in phase. These findings validate the effectiveness of the proposed virtual flux-based direct power control strategy, demonstrating its suitability for DC distribution applications in maritime vessels.

Background: Chronic low back pain (CLBP) is associated with trunk and lower extremity muscle weakness. Kneeling squat (KS) is a hip-focused exercise commonly used in the activities of daily living. However, research on trunk and lower extremity muscle activity across movement phases (ascending, holding, and descending) during KS remains limited and warrants further investigation. Objects: To determine the muscle activity of transversus abdominis/internal oblique (TrA/IO), erector spinae, gluteus maximus (Gmax), gluteus medius (Gmed), rectus femoris (RF) in the contraction phases of KS in individuals with CLBP. Methods: Surface electromyography data were recorded during KS across the ascending, holding, and descending phases on the side with CLBP. A 60-bit metronome was used to control the exercise speed. Results: The muscle activity of the TrA/IO was significantly higher during the holding phase than during the ascending and descending phases. The Gmax and Gmed were significantly higher during the holding phase than during the descending phase, whereas, RF was significantly higher during the ascending phase than during the holding and descending phases. Conclusion: The holding phase of KS may be recommended as a trunk and lower extremity exercise to increase in TrA/IO, Gmax, and Gmed muscle activity. Additionally, the ascending phase activates RF muscle in individuals with CLBP.

Background: Chronic low back pain (CLBP) is a common health problem among female caregivers. In Korea, 70.4% of caregivers experience LBP after caregiving. The prevalence of LBP was higher in female caregivers of patients who required physical assistance with transfer than in those caring for patients who did not require physical assistance. Lifting movements, such as patient transfer and positioning, are associated with lumbopelvic stability (LPS) and knee muscle strength. However, no studies have investigated the differences in LPS and knee muscle strength between female caregivers with and without CLBP. Objects: This study was conducted to investigate the differences of the LPS, knee extension strength (KES) and knee flexion strength (KFS) between female caregivers with and without CLBP. Methods: Thirty-one female caregivers participated in this study. Participants were divided into two groups: (1) caregivers without CLBP (n = 13) and (2) caregivers with CLBP (n = 18). LPS, KES, and KFS levels were measured. An independent t-test was used to compare the LPS, KES, and KFS between caregivers with and without CLBP. The statistical significance was set at α of 0.05. Results: The LPS and KES scores were significantly lower in caregivers with CLBP than those without. In contrast, the KFS did not differ significantly between the groups. Conclusion: This study observed associations of both LPS and KES with CLBP among female caregivers.

공공하수 처리시설 방류수 T-N 기준을 만족하기 위해서는 호기조에서 질산화가 안정적으로 이루어져야 한다. 수온 및 pH가 질산화에 민감한 영향을 주고 있음에도 불구하고 기존 하수처리장 설계 시 동절기 저수온만 고려하고 호기조 pH는 상시 7.0으로 가정하여 설계하고 있다. 이에 본 연구에서는 MLE 공법 하수처리장의 생물반응조 유입수 알칼리도를 계절별로 파악하여 시뮬레이션을 수행하고, 알칼리도 변화가 호기조 pH 및 NH3-N 농도에 주는 영향을 확인하였다. 연구대상 처리장의 계절별 일평균 생물반응조 유입수 알칼리도는 춘/추절기 190 mg CaCO3/L, 하절기 185 mg CaCO3/L 그리고 동절기 210 mg CaCO3/L로 하절기에 저농도 알칼리도가 유입되는 것을 실험을 통해 파악하였다. 시뮬레이션 결과, 동절기 MLSS 농도가 2,500 mg/L인 경우, 유입수 알칼리도 변화와 관계없이 호기조 NH3-N 농도는 10 mg/L 이상이며 알칼리제 투입을 통한 목표 호기조 NH3-N 농도 2.5 mg/L 달성이 어려운 것으로 확인되었다. MLSS 농도가 3,000 및 3,500 mg/L인 경우에는 유입수 알칼리도에 따라 호기조 NH3-N 농도는 각각 1.3-5.0 mg/L와 0.8-3.1 mg/L의 범위인 것을 파악하였다. 춘/추절기 및 하절기 생물반응조 유입수 알칼리도가 하한치가 유입되는 경우, MLSS 및 DO 농도와 관계 없이 pH와 알칼리도가 제한 인자로 작용하여 호기조 NH3-N 농도 2.5 mg/L 이하를 만족하지 못하였다. 반면 유입수 알칼리도가 충분한 조건에서는 DO 및 MLSS 농도만 제어해도 안정적인 질산화가 가능한 것으로 나타났다. 또한 춘/추절기 및 하절기에 호기조 DO 농도가 1.0 mg/L가 되어도 질산화가 발생되는 것이 확인되어 처리장 운영에 있어서 탄소 발생 저감 방안이 수행될 수 있다.

The study on the efficiency improvement of qualification procedures for low Earth orbit (LEO) satellites analyzed the differences between the European ECSS and the American NASA standards. ECSS allows flexible test tailoring to accommodate project-specific requirements, whereas NASA enforces strict standardized procedures to ensure high reliability. Additionally, ECSS prioritizes cost efficiency, while NASA emphasizes reliability. In terms of application scope, NASA focuses on private-sector collaborations, whereas ECSS is centered on cooperative projects within Europe. Based on this comparative analysis, this study proposes a qualification framework for Korean LEO satellites, categorizing 18 qualification test items into mandatory and optional groups. This approach is expected to enhance the reliability, performance, and stability of satellite systems. Therefore, the proposed Korean qualification test sequence should be implemented and incorporated into national defense standards. This will strengthen the systematic structure of the qualification process while maximizing efficiency in terms of testing time and cost.

This study explored factors affecting variability in second language (L2) learning motivation among Korean university students and how they appraised their L2 learning experience. In this study, 85 undergraduate students majoring in English or English education from three universities in Seoul, South Korea, reflected on their past English learning experience. They drew a motigraph and wrote a retrospective reflection essay covering their English learning that spanned over ten years. Researchers divided participants into two groups: a high variability (HV) group and a low variability (LV) group. Data were analyzed using open, axial, and selective coding. Findings suggest thncontextual factors such as the learning method, atmosphere, and situation were main (de)motivational factors for the HV group. In contrast, the LV group was (de)motivated by intrapersonal factors, including the learning context appraisal. These results imply that visualizing long and short-term goals and positive appraisal of the L2 learning experience can help L2 learners maintain a stable pattern in L2 learning motivation.

Reinforced concrete (RC) piloti buildings are vulnerable in the event of earthquake because the stiffness in the 1st story columns is weak to compare with the members in upper stories. In this study, seismic performances of RC piloti structures were evaluated considering with different types of floor plane layouts according to core eccentricity. With four types of floor plane layouts, five stories plioti structures were evaluated by two approaches, a nonlinear pushover analysis and a nonlinear time-history analysis. In order to improve seismic performances by satisfying the collapse prevention (CP) level, two ductile reinforcing methods by carbon fiber sheets and steel jackets were applied. Due to eccentricities in stiffness and mass with directions of plane and vertical stories, piloti structures were greatly influenced by higher order modes, so the seismic performances by the time-history analysis were significantly different from by the static pushover analysis.

Photometric and spectroscopic observations of GV Leo were performed from 2017 to 2024. The light curves show a flat bottom at the primary eclipse and the conventional O’Connell effect. The echelle spectra reveal that the effective temperature and rotation velocity of the more massive secondary are Teff,2 = 5220 ± 120 K and v2 sin i = 223 ± 40 kms−1, respectively. Our binary modeling indicates that the program target is a W-subclass contact binary with a mass ratio of q = 5.48, an inclination angle of i = 81.◦68, a temperature difference of (Teff,1 − Teff,2) = 154 K, and a filling factor of f = 36%. The light asymmetries were reasonably modeled by a dark starspot on the secondary’s photosphere. Including our 26 minimum epochs, 84 times of minimum light were used to investigate the orbital period of the system. We found that the eclipse times of GV Leo have varied by a sinusoid with a period of 14.9 years and a semi-amplitude of 0.0076 days superimposed on a downward parabola. The periodic modulation is interpreted as a light time effect produced by an unseen outer tertiary with a minimum mass of 0.26 M⊙, while the parabolic component is thought to be a combination of mass transfer (secondary to primary) and angular momentum loss driven by magnetic braking. The circumbinary tertiary would have caused the eclipsing pair of GV Leo to evolve into its current short-period contact state by removing angular momentum from the primordial widish binary.

본 연구에서는 저온 스트레스에서 살리실산(SA, salicylic acid)의 경엽처리가 배추의 광합성, 생리활성 및 생육에 미치는 영향을 구명하고자 하였다. SA을 각각 0.25, 0.5 및 1mM 농도로 주당 100mL을 4일 간격으로 3회 엽면 살포하였고, 7일간 저온 스트레스를 처리하였다. SA 처리 시 광합성 속도, 기공전도도, 세포 내 CO2 농도 및 증산 속도는 무처리 대비 증 가하였고, 2회 처리 후 가장 높았다. MDA 함량은 무처리 대 비 유의한 차이를 보이며 감소하였다. APX, CAT, POD 및 SOD 활성은 무처리 대비 현저하게 증가하였으며, 각각 최대 62, 81, 55 및 26% 증가하였다. 배추의 생육 특성은 무처리와 유의한 차이를 보이지 않았으나, 수량 지수는 2－6% 정도 증 가하였다. 따라서 SA의 경엽처리는 배추의 생육, 광합성 특성 및 항산화 효소 활성을 증대시켜 저온 스트레스를 완화 하였 고, 적정농도는 0.5－1mM이라 판단된다.

Background: When shorter muscles are restored to normal, non-specific low back pain, which is the mechanism that causes pain along with muscle relaxation, disappears. Among the stretching methods, self-stretching is a good exercise method not only for treatment but also for preventive purposes. Objectives: To find out what is the most effective method of self-stretching, which is often used in treatment and preventive arbitration, which can reduce muscle activity and increase spinal flexibility in patients with non-specific back pain. Design: Randomized controlled trials. Methods: Three self-stretching exercise methods for erector spinae are randomly assigned to 13 people each, and three self-stretching exercise methods are performed for each study subject. Surface electromyography using, was performed to measure the erector spinae muscle activity. flexibility was measured through Trunk flexion test in a standing position. Muscle activity and flexibility were measured before and after stretching. Results: The difference in muscle activity and flexibility in the three groups, including cat stretching, seated stretching, and Reclining stretching, all showed statistically significant differences. There was no statistically significant difference in comparison between the three groups of stretch muscle activity. However, a statistically significant difference was shown in the comparison of the variability between the three groups of flexibility. In a post-mortem analysis comparing the amount of change in flexibility, the flexibility of the seated stretching in the chair increased significantly compared to the cat stretching group. Conclusion: It can be confirmed that the stretching method of the erector spinae, cat stretching, seated stretching, and Reclining stretching, all have positive effects on muscle activity and flexibility.

Background: In patients with low back pain (LBP), weakened core muscles and impaired proprioception contribute to decreased spinal stability and LBP recurrence. Objectives: To investigate the effects of abdominal bracing exercises (BE) and kinetic link training (BEKLT) on pain, balance, and proprioception in LBP patients. Design: Randomized controlled trial. Methods: Sixteen adults with LBP were randomly assigned to a BE group or a BEKLT group. Both groups completed a four-week intervention (three sessions per week). Pain was assessed using the visual analog scale (VAS), proprioception with the lumbar reposition sense test, and balance with the BT4 system. Results: Both groups showed significant reductions in VAS and proprioception error (P<.05), with no inter-group differences. In dynamic balance (limits of stability), the BE group improved in rearward, left, and right angles, while the BEKLT group improved in forward, rearward, and left angles (P<.05). A significant difference was observed in the forward leaning angle between groups (P<.05). For static balance, both groups showed significant reductions in trace length and C90 area (P<.05), with no inter-group differences. Conclusion: The findings suggest that both BE and BEKLT are effective interventions for reducing pain and improving proprioception and balance in LBP, with BEKLT providing additional benefits for dynamic balance.