With the increasing scale and span of bridge structures, there has been a growing demand to reduce construction accidents and shorten the duration of pier construction. Conventional pier construction methods using steel formworks involve repetitive installation and dismantling processes, which require high-level work and pose a significant risk of fall accidents. In addition, the complexity of these processes limits construction efficiency. In this study, a rapid pier construction method using precast concrete stay-in-place formwork applied to pier columns and copings was proposed, and its structural performance and constructability were evaluated through experimental and analytical investigations. Composite and bond performance tests between the precast stay-in-place formwork and cast-in-place concrete were conducted for both column and coping components. Furthermore, construction-stage analyses were performed to assess structural stability during construction. The experimental results showed that the flexural strength of the composite column section reached approximately 105% of that of the monolithic reinforced concrete section, while the composite coping section achieved approximately 107%. The bond performance test results also confirmed that sufficient bond strength satisfying the design requirements was secured. Constructability analysis indicated that the elimination of the formwork dismantling process enables a reduction in construction duration and a significant improvement in construction safety compared to conventional steel formwork methods. Therefore, the proposed PCS-Pier method can be considered a viable alternative for pier construction, providing both structural safety and improved construction efficiency.

This study proposes a data-driven framework for analyzing freeway driving behavior using multiple real-world trajectory datasets, and applies it consistently to mainline and ramp sections. The four large-scale datasets—namely highD, exiD, NGSIM I-80, and NGSIM US- 101—were processed through a unified preprocessing pipeline that converted all variables to International System Units(SI), resampled trajectories to 10 Hz, applied Savitzky-Golay smoothing to speed, and removed physically implausible and statistical outliers based on joint physical-statistical criteria. For each vehicle, 24 summary features were constructed from six longitudinal indicators–speed, acceleration, deceleration, time headway (THW), distance headway (DHW), and time-to-collision (TTC)–using their minimum, maximum, mean, and standard deviation. Indicator distributions by road type were compared using relative frequency histograms with common binning; then, principal component analysis (PCA) and K-means clustering were applied independently to each dataset. The leading principal components revealed interpretable axes related to longitudinal driving intensity (speed and acceleration level), safety margin (THW/DHW/TTC), and onramp sections; responsiveness was characterized by acceleration-deceleration variability, as observed within the analyzed datasets. Cluster interpretation yielded four relative driving behavior categories–aggressive, responsive, stable, and defensive–defined within each dataset based on indicator levels and variability rather than absolute thresholds.

This study aims to evaluate the feasibility of cementless concrete using industrial byproducts as an eco-friendly alternative to conventional cement concrete. Ground-granulated blast-furnace slag (GGBFS), fly ash (FA), and silica fume (SF) were employed as binder materials, and the mechanical performance, plastic shrinkage behavior, and microstructural characteristics of cementless concrete were investigated to verify its applicability as a structural and shotcrete material capable of reducing CO₂ emissions. Cementless concrete mixtures were prepared using GGBFS, FA, and SF as binders, activated by sodium hydroxide and sodium silicate with water-to-binder (W/B) ratios of 0.40, 0.45, and 0.50. Conventional cement concrete with equivalent water ratios was used for comparison. Compressive strength tests were conducted at curing ages of 1, 3, 7, 14, and 28 days. Plastic shrinkage cracking was evaluated according to the ASTM C1579 standard. Microstructural development and reaction products were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Cementless concrete with W/B ratios of 0.45 and 0.50 exhibited compressive strength comparable to or higher than that of cement concrete from early ages and demonstrated superior 28-day strength performance. No plastic shrinkage cracking was observed for any mixture, indicating excellent early-age crack resistance. SEM analysis revealed progressive densification of the microstructure owing to the formation of C-(A)-S-H and N-A-S-H gel phases with increasing curing age. XRD results showed limited portlandite formation in cementless concrete, accompanied by an increased development of aluminosilicate reaction products after 7 days, resulting in reduced porosity and enhanced structural compactness. Experimental results confirmed that cementless concrete incorporating industrial byproducts can achieve mechanical performance and durability characteristics comparable to or exceeding those of conventional cement concrete when an appropriate W/B ratio is applied. Reduced portlandite formation and dominant alkali-activated reaction products contributed to the improved chemical stability and resistance to deterioration. Therefore, cementless concrete has a strong potential as a sustainable construction material capable of reducing CO₂ emissions while maintaining its structural performance, particularly for shotcrete applications.

본 연구는 아마추어 러너에서 체성분이 폐 기능과 어떻게 연관되는 지를 검증하기 위해 수행한 단면 상관관계 연구이다. 만 20–45세의 아 마추어 러너 48명을 단일 방문으로 평가하였고, 생체전기저항분석기로 골격근량(skeletal muscle mass, SMM)과 체지방률(percent body fat, PBF)을 측정하였으며, 표준화된 폐 기능 지표로 노력성 폐활량 (forced vital capacity, FVC), 1초간 노력성 호기량(forced expiratory volume in 1 second, FEV1), 최대 자발적 환기량(maximal voluntary ventilation, MVV)을 평가하였다. 수집된 자료는 유의수준 .05에서 Pearson 상관분석과 단변량 선형회귀분석으로 검토하였다. 분석 결과, SMM은 FVC(r=.78, p<.01), FEV1(r=.74, p<.01), MVV(r=.55, p<.01) 와 유의한 양의 상관을 보였고, PBF는 FVC(r=−.5, p<.01)와 유의한 음의 상관, FEV1(r=−.35, p<.05)과 약한 음의 상관을 나타냈다. 회귀분석에 서는 SMM이 FVC(R²=.60), FEV1(R²=.54), MVV(R²=.31)를 각각 유의 하게 설명하였으며, PBF는 FVC(R²=.25)에 대해 유의한 음의 설명력을 보였다. 이러한 결과는 근육의 충분성이 환기 수행능력을 지지하고, 지 방의 과다 축적이 폐 용적 및 유량 지표에 불리하게 작용함을 시사한 다. 단면 설계와 BIA 기반 측정이라는 한계를 고려할 때 인과 해석은 신중해야 하나, 아마추어 러너의 호흡 수행능력 최적화를 위해 근력, 근 지구력 중심의 훈련과 체지방 관리가 유효한 표적이 될 수 있음을 제안 하며, 향후 종단, 중재 설계를 통한 인과성 검증과 이중에너지 X선 흡수 계측(dual-energy X-ray absorptiometry, DXA)/자기공명영상(magnetic resonance imaging, MRI) 및 중심성 지방 지표를 포함한 정밀 측정 이 요구된다.

리튬 이온 배터리의 안전성과 지속가능성에 대한 수요 증가는 기존의 폴리올레핀 분리막을 대체할 수 있는 셀룰 로오스 기반 분리막 개발을 촉진하고 있다. 본 총설은 수압 공정을 통해 제조된 셀룰로오스 아세테이트(cellulose acetate, CA) 분리막의 최적화 전략을 종합적으로 분석하였다. 특히, 기공 구조, 열적 안정성, 기계적 강도를 조절하는 데 있어 유기 및 무 기 첨가제의 역할을 중점적으로 고찰하였다. 유기산은 고분자 사슬의 가소화를 통해 나노기공 형성을 유도하여 높은 기공률 과 조절 가능한 기공 크기를 제공하지만, 열적 안정성이 다소 저하되는 한계가 있다. 반면, 무기 염과 산화물, 특히 칼슘계 화 합물은 이온 상호작용과 가교결합을 통해 열적 안정성을 크게 향상시키는 것으로 나타났다.

In this paper, for a seismic analysis of an offshore subsea manifold, Response Spectrum Analysis(RSA) and Time History Analysis(THA) were conducted under a various analysis conditions. Response spectrum and seismic design procedure have followed ISO19901-2 code. In case of THA, The response spectrum were converted into artificial earthquake history and both of Explicit and Implicit solvers were used to examine the characteristics of seismic analysis. For the verification, Various seismic analysis methods were applied on a single degree of freedom beam model and a simplified model of the actual manifold. The difference between the results of RSA and THA on the simplified manyfold model evaluated for the analysis of the actual manifold. Because THA is impossible in case of real complex structure such as a manifold, Safety of the actual manifold structure was accessed by using the RSA and the difference between the results of RSA and THA from the simplified model.

Abstract In this study, the antioxidant activity of water and ethanol extracts from Hibiscus esculentus, Cirsium japonicum, Zizania latifolia and Kalopanax pictus for functional food source were examined. The optimal conditions for phenolic compounds extraction from medicinal plants were at 50% ethanol with Hibiscus esculentus and Cirsium japonicum var. ussuriense, at 40% ethanol with Kalopanax pictus and at 60% ethanol with Zizania latifolia. The total phenolic contents from the extracts of medical plants were determined to be 2.72~34.15 mg/g in the water extracts and 2.83~34.23 mg/g in the ethanol extracts. The electron-donating abilities (EDA) of the water and ethanol extracts were both above 74% at the low concentration of 50 μg/mL. The ABTS radical-cation decolorization was above 88% at 100 μg/mL concentration in all the extracts of various medicinal plants. The antioxidant protection factor (PF) in the water and ethanol extracts of the Cirsium japonicum var. ussuriense extracts was 1.73 ± 0.02 PF and 1.76 ± 0.01 PF at 50 μg/mL concentration respectively, and was higher than those of the other medicinal-plant extracts. The TBARs inhibition rates of all the medicinal-plant extracts, were above 80% at the 50 μg/mL concentration except Hibiscus esculentus. These results confirmed that the various oriental medicinal plants (Hibiscus esculentus, Cirsium japonicum var. ussuriense, Kalopanax pictus and Zizania latifolia) that were included in this study are useful anti-oxidant and functional-food resources.

The aim of this research was to investigate the anti-oxidantive activities of extracts from Chionanthus retusus leaves, fruits and flower. The content of phenolics were 20.8 mg/g in water extracts and 32.2 mg/g in 90% ethanol extracts from flower. The DPPH free radical scavenging activity of extracts from Chionanthus retusus was above 70% at phenolic concentration 100 μg/mL. The ABTS radical decolorization activities of water and ethanol extracts were both above 80% at 100 μg/mL phenolic concentration, respectively. The antioxidant protection factor(PF) of water and 80% ethanol extracts from leaves was the highest as 2.27 PF and 1.70 PF at 50 μg/mL phenolic concentration. The TBARs inhibition rate of the Chionanthus retusus extracts, was above 70% at 200 μg/mL phenolic concentration. The anti-oxidantive activities of extracts from leaves were shown more active than BHT as a positive control except TBARs. These results confirmed that the extracts from Chionanthus retusus leaves, fruits and flower was shown the high anti-oxidant activity. The results can be expected isolated phenolic compounds from Chionanthus retusus to use as functional beauty food resource.

본 연구는 1998년 7월부터 9월까지 득량만 19개 정점 표층에서 수질, 식물플랑크톤 군집의 구조와 동태 및 적조의 특징을 규명하였다. 조사기간 중 월별 평균 수온은 24.0~28.6℃, 염분은 25.0~28.6‰로 월별 및 정점간 변이가 컸다. 본 해역의 Chlorophyll-α의 농도는 7월과 8월에 평균 11.59mg/m3, 7.52mg/m3를 나타내어 일차생산이 높았으며,

The objective of this study was to identify the anti-oxidation, astringent, and inhibition effects of wild Ligularia fischeri on hyaluronidase and angiotensin conerting enzyme (ACE). In order to identify the total phenolic compound (TPC), various solvents were used for extraction showing hot water extract with the highest value of 14.42 GAE mg/g. In addition, ABTS radical scavenging activity measurements revealed an anti-oxdiation effect of 98.64-99.84% a hot water extract concentration of 50-200 μg/mL and a radical scavenging activity of 95.14-98.96% at a 60% ethanol extract content. If expressed in antioxidant protection factors (PF), the hot water extract showed 0.59-1.02 PF and the 60% ethanol sample displayed 0.30-0.74 PF. To identify the bio-activity effect, the hyaluronidase inhibition effect was determined as 4.66-35.00% in a 50-200 μg/mL hot water extract. Considering ACE inhibition effect, the hot water extract and 60% ethanol sample showed 0-64.24% and 46.12-69.64% inhibition effect, respectively. Lastly, when taking into account the astringent effect, the hot water extract with 50-200 μg/mL TPC concentration showed 15.68-26.92% and the 60% ethanol sample with an equal concentration exhibited 49.48-86.84%, which indicates the possibility to apply this product as a cosmetic source for pore contraction. Therefore, wild Ligularia fischeri extract can be used for anti-inflammation, high-blood pressure prevention, and as a source for health functional food with anti-oxidative properties.

This study was designed to determine the biological activities of Chionanthus retusus flower extracts. Water and 90% ethanol extracts of C. retusus flower were prepared. The inhibitory activities of water and ethanol extracts with a phenolic content of 200 μg/mL against xanthine oxidase were 25.60% and 15.92%, respectively. Further, the water extract did not show any inhibitory activity against α-glucosidase whereas the ethanol extract showed 100.00% inhibition of α-glucosidase. The inhibitory activities of the extracts against tyrosinase were 17.27% (water extract) and 36.13% (ethanol extract), which suggest that the extracts may have a whitening effect. The water extract did not inhibit elastase activity but showed a collagenase-inhibitory activity of 20.21%. On the contrary, the ethanol extract showed 96.26% and 35.93% inhibition of collagenase and elastase, respectively. These findings suggest that the extracts may have an anti-wrinkle effect. Lastly, the extracts showed a hyaluronidase inhibitory activity of 36.96% (water extract) and 88.70% (ethanol extract), suggesting that they may have an anti-inflammatory effect. The results indicate that C. retusus flower extracts containing phenolic compounds can be used as functional resources because they have anti-gout, carbohydrate degradation-inhibitory, whitening, anti-wrinkle, and anti-inflammatory effects.

본 연구에서 마삭줄(Trachelospermum asiaticum var. intermedium Nakai)을 용매별과 ethanol 농도별로 추출한 결과, 용매별 추출에서 ethanol 추출물이 20.8 mg/g으로 가장 높은 phenolic compounds 용출량을 보였고, 농도별 추출에서 70% ethanol 추출물이 38.1 mg/g으로 가장 높았다. 물 추출물은 16.8 mg/g의 phenolic compounds 용출량을 보였다. 마삭줄을 물과 ethanol을 추출용매로 사용하여 항산화 효과와 항통풍 및 항당뇨 효과를 확인하여 건강 기능성 식품으로의 가능성을 증명 하고자 하였다. DPPH radical 소거능 측정 결과, 100 μg/mL phenolic compounds의 농도에서 물 추출물은 80.9%, 70% ethanol 추출물은 83.1%의 활성을 나타내었다. ABTS radical 소거능 측정 결과 200 μg/mL phenolic compounds의 농도에서 물 추출물은 95.0%, 70% ethanol 추출물은 95.8%의 소거능력을 나타내었다. PF 측정결과, 100 μg/mL phenolic compounds의 농도에서 물 추출물은 2.43 PF, 70% ethanol 추출물에서는 2.45 PF를 나타내었다. TBARs 측정 결과, 200 μg/mL phenolic compounds의 농도에서 물과 70% ethanol 추출물에서 89.9%와 89.3%의 활성을 나타내었다. 통풍 억제 효과 측정 결과, 200 μg/mL phenolic compounds의 농도에서 물 추출물은 33.3%, 70% ethanol 추출물은 50.5%의 저해 효과를 나타내었다. α-glucosidase 저해 효과 측정 결과, 물 추출물에는 저해 효과가 나타나지 않았고, 70% ethanol 추출물에서는 200 μg/mL phenolic compounds의 농도에서 92.6%의 저해 효과를 나타내었다. 이러한 결과들로 미루어 보았을 때 마삭줄 추출물은 항산화 작용과 건강 기능성 식품으로 활용 가능성을 확인할 수 있었다.

본 연구에서는 긴병꽃풀의 항산화 효과와 기능성을 활용한 양갱을 제조하여 기계적 특성을 측정하고, 관능적 기호도 평가를 실시하였다. 생리활성 물질의 양을 측정하기 위하여 페놀성 화합물 정량을 실시한 결과 긴병꽃풀 열수추출물에서 12.99±0.30 mg/g, 70% ethanol 추출물에서 3.14±0.07 mg/g으로 나타내었다. 50-200 μg/mL의 농도에서 항산화 효과를 측정한 결과, 전자공여능은 열수추출물과 70% ethanol 추출물에서 각각 77.16-78.24%, 73.04-77.00%로 나타내었으며, ABTS는 84.35-99.75%, 83.74-99.55%로 나타내었다. Antioxidant protection factor(PF)는 1.54-1.62, 1.62-2.09 PF를 나타내었으며, TBARs는 42.93-94.09%, 91.05-95.19%로 나타내었다. 긴병꽃풀 추출물의 열수추출물과 70% ethanol 추출물은 거의 비슷한 항산화 효과를 나타내었으나, PF와 TBARs에서는 70% ethanol 추출물에서 더 우수한 항산화 효과를 나타내었다. Tyrosinase 저해활성은 열수추출물에서는 효과가 나타나지 않았으며, 70% ethanol 추출물에서는 30.32-40.56%의 저해활성을 나타내었다. Hyaluronidase 저해활성은 14.23-40.93%, 57.45-72.88%로 70% ethanol 추출물이 더 우수한 저해활성을 나타내었으며, 50-100 μg/mL의 저농도에서는 positive control로 사용한 PDTC보다 우수한 저해활성을 나타내었다. 색도는 긴병꽃풀 분말의 첨가량이 증가할수록 L 값과 a 값은 감소하는 경향을 나타내었고 b 값은 일정하게 나타내었다. 기계적 조직감은 경도와 탄력성에서 긴병꽃풀 분말의 첨가량이 증가할수록 감소하는 경향을 나타내었고, 응집성은 첨가량과 관계없이 일정한 값을 나타내었다. 씹힘성은 2.0%에서 가장 높은 수치를 나타내었으나 대조군과 첨가군 간의 유의적 차이는 나타나지 않았고, 긴병꽃풀 분말이 양갱의 기계적 조직감에 영향을 준다는 것을 확인할 수 있었다. 긴병꽃풀 분말 첨가 양갱의 관능적 기호도는 점도, 경도, 씹힘성, 탄력성, 맛, 향, 전반적인 기호도 항목에서 대조군을 제외하고 1.0% 이하 첨가군에서 기호도가 높게 나타내었으며 2.0% 첨가군은 모든 항목에서 가장 낮은 기호도를 나타내었다. 위 결과에 따라 긴병꽃풀 분말을 이용한 양갱 제조에는 1.0% 이하의 농도를 사용하여 제조하는 것이 가장 적합하다고 판단되었다.