This paper presents a finite-difference method (FDM)-based heat-transfer model for predicting black-ice formation on asphalt pavements and establishes decision criteria using only meteorological data. Black ice is a major cause of winter road accidents and forms under specific surface temperature and moisture conditions; however, its accurate prediction remains challenging owing to dynamic environmental interactions. The FDM incorporates thermodynamic properties, initial pavement-temperature profiles, and surface heat-transfer mechanisms, i.e., radiation, convection, and conduction. Sensitivity analysis shows the necessity of a 28-d stabilization period for reliable winter predictions. Black-ice prediction logic evaluates the surface conditions, relative humidity, wind speed, and latent-heat accumulation to assess phase changes. Field data from Nonsancheon Bridge were used for validation, where a maximum prediction accuracy of 64% is indicated in specific cases despite the overestimation of surface temperatures compared with sensor measurements. These findings highlight the challenges posed by wet surface conditions and prolonged latent-heat retention, which extend the predicted freezing duration. This study provides a theoretically grounded methodology for predicting black ice on various road structures without necessitating additional measurements. Future studies shall focus on enhancing the model by integrating vehicle-induced heat effects, solar radiation, and improved weather-prediction data while comparing the FDM with machine-learning approaches for performance optimization. The results of this study offer a foundation for developing efficient road-safety measures during winter.

The heat transfer characteristics of double-pipe spiral heat exchanger using aluminum oxide nano-fluid were investigated by three different sizes of curvature size, experimentally. Five concentration of nano-fluid as working fluid were made and tested to analyze the heat transfer characteristics. As results, the heat transfer performance was improved at 0.25% of nano-fluid due to high thermal conductivity, however, as the concentration of nanofluid increased (~2.0%), the heat transfer performance deteriorated due to the increase in thermal resistance caused by the sedimentation of particles in the flow path. In addition, the nano-fluid has a higher pressure drop than water due to its high density and viscosity. The optimal range for heat transfer enhancement of nano-fluid was found to be less than 4.0 LPM in flow rate and 0.25% of nano-fluid concentration in this study.

초음속 혹은 극초음속 미사일의 레이돔은 공력 가열로 인해 과도한 열유속에 노출된다. 또한 미사일은 발사 후 속도와 고도가 변화 하면서 이에 따라 레이돔에 가해지는 열유속이 변화한다. 이러한 열부하에 의해 레이돔의 온도가 소재의 허용 온도를 초과하면, 레이 돔은 레이더를 보호하는 기능을 상실하게 된다. 따라서 비행 시나리오에 따른 레이돔의 열전달 특성을 고려하여 레이돔을 설계해야 한다. 본 연구에서는 준-비정상 기법을 적용하여 가상의 비행 시나리오에서의 레이돔의 열전달 특성을 분석하고 준-비정상 기법의 정 확도와 효율성을 평가하였다. 준-비정상 기법을 적용하여 시간에 따른 레이돔 외벽의 열유속과 온도 분포를 도출하였으며, 15초 이후 레이돔 외벽의 온도가 소재의 허용 온도 이상으로 가열되는 부분이 있는 것을 확인하였다. 또한 준-비정상 기법을 통해 도출된 결과 와 비정상 해석 결과를 비교하여 레이돔 평균 온도 측면에서 15% 이내의 오차로 예측할 수 있고 해석 소요 시간은 75%가 단축되는 것 을 확인하여 준-비정상 기법의 효율성을 입증하였다.

이 논문은 뮤지컬 『라이온 킹』에서 그루브(Groove)가 캐릭터 형성, 감정 전달 및 스 토리 전개에 미치는 영향을 분석하였다. 연구의 필요성 및 목적은 그루브가 단순한 리듬 적 요소를 넘어 서사의 긴장감 조성과 정서적 몰입에 기여하는 핵심적 역할을 규명하기 위한 목적으로 수행되었다. 연구 방법으로는 주요 장면 <Circle of Life>, <Hakuna Matata>, <He Lives in You>, <Be Prepared>를 대상으로 악보 분석 및 연출 관찰을 통해 그루브의 리듬적 특성과 서사적 기여를 심층적으로 탐구하였으며, 특히 리듬 구조, 악 기 구성, 음악적 동선 등을 분석하여 각 장면에서 그루브가 어떻게 구현되고, 캐릭터와 서사에 어떠한 영향을 미치는지를 실증적으로 검토하였다. 연구 결과는 그루브가 캐릭 터의 내면적 변화와 감정을 구체화하며, 주요 서사의 전환점에서 극적 긴장감을 조성하 는 중요한 역할을 수행하는 것으로 나타났다. 이 논문은 뮤지컬에서 그루브의 학문적· 실용적 의의를 강조하며, 뮤지컬 창작과 분석 과정에 기초 자료를 제공하였다.

The hydrogen valve used in this study is intended to be applied to a automobile, and since there is a limit to the length of the stem, it is necessary to review the optimized stem, and for this, it is required to investigate the heat transfer characteristics of the hydrogen shut-off valve. For this, the temperature of the entire shut-off valve and especially the plunger and O-ring, which are key components in the solenoid valve driving the hydrogen shut-off valve, was calculated using the ANSYS-CFX flow analysis program. From the analysis results, the length of the stem capable of maintaining the design temperature of -40℃ or higher should be at least 139 mm, and it is judged that it should be 140 mm or more considering safety. When determining the stem length of the hydrogen blocking valve for automobiles, constraints on installation in automobiles should be considered.

본 연구는 매체 간 전환이 활발하게 진행되는 콘텐츠 시장 분위기에 발맞추어, 뮤지컬 공연이 뮤지컬 영화로 매체 전환되는 것에 긍정적인 영향을 주고자 연구되었다. 또한, 뮤지컬 공연이 뮤 지컬 영화로 매체 전환 시 공간 선택의 용이성과 카메라 기법의 활용이 인물의 세세한 ‘감정’과 ‘심리 상태의 변화’ 등을 보여줌으로써, 작품의 메시지를 강화할 수 있는지 확인하기 위한 목적을 가지고 있다. 연구 방법은 앙리 르페브르의 공간 이론 중 ‘사회적 공간’ 개념과 ‘추상 공간’ 개념, 조지 레이코프와 마크 존슨의 ‘지향적 은유’ 개념을 기반으로 뮤지컬 영화 <레 미제라블> 속 자베 르의 주요 장면인 “Stars”와 “Soliloquy(Javert’s Suicide)”를 분석하는 것이다. “Stars” 장면에 서는 노트르담 대성당과 파리 경시청이 가지는 공간적 가치와 높이에 따른 지향적 은유에 따라 작품의 메시지가 상징되어 강화되었음을 확인했다. “Soliloquy(Javert’s Suicide)” 장면에서는 노트르담 대성당과 대하수구, 세느강의 수로 등이 가지는 공간적 가치와 자베르의 권위를 상징하 는 도구인 총과 훈장 등을 활용해 만든 은유로 작품의 메시지가 강화되었음을 확인했다. 이처럼 본 연구는 뮤지컬 공연이 뮤지컬 영화로 전환할 때의 장점을 확인했다. 또한, 본 연구를 통해서 뮤지컬 영화 제작에 있어 공간과 소품 배치, 카메라 기법을 통한 공간과 소품에 대한 집중 등을 통해 메시지 전달력이 강화될 수 있다는 결론이 도출되었다. 본 연구는 작품의 주인공인 장 발장 이 아닌 안타고니스트 자베르를 중심에 두고 분석했다는 점과 사십 곡이 넘는 넘버로 이루어진 작품을 다루고 있지만 두 곡만을 분석했다는 점에서 한계를 가지며, 범주를 더욱 넓혀 본 연구의 맹점을 해결한 추가 연구가 이어지기를 제언했다.

Research has been conducted on acoustic metamaterials that control the transmission characteristics of reflected and refracted waves using phase delay by resonators. Using one-dimensional theory, the phase delay equations for the 1/4 wavelength and Helmholtz resonator are presented. These one-dimensional analysis results are compared with the results predicted by three-dimensional FEM. The advantages and disadvantages of 1/4 wavelength and Helmholtz resonator were confirmed in implementing phase delay. An acoustic metamaterial with a refraction angle of 30° was manufactured using multiple tubes and then the sound pressure distribution was measured. A relatively large sound pressure was measured at the target position of 30°, which was compared with the 3D FEM analysis results. Simulations confirmed that a phase delay range closer to 2π was more effective in refraction, but varying the number of resonators was found to have minimal impact on which additional research is needed for generalization.

This study deals with the vibration transmissibility of a vibration isolation device, which is composed of frictional damping and nonlinear softening springs, when its base is harmonically excited. The SCAP method, a type of averaging method, is employed to obtain steady-state responses. The vibration characteristics due to excitation of the base are investigated through the analysis of displacement transmissibility in the steady-state response. In this process, displacement transmissibility for design parameters is analyzed, and the stability of the response is also investigated. The vibration isolation effect due to frictional damping is found to be more effective in the case of the softening spring than in the case of the hardening spring. Additionally, the pattern of the jump phenomenon observed during frequency sweeping, both upward and downward, has been identified.

The heat transfer characteristics of double-pipe spiral heat exchanger were investigated by various curvature sizes, experimentally. The three different sizes of heat exchanger were made and tested with water as a working fluid to analyze the heat transfer characteristics. The heat transfer rates, overall heat transfer coefficient and pressure drop were analyzed with various heat exchanger sizes (i.e., curvature ratios). As result, the heat transfer rate increased with increasing the size of the heat exchanger as the flow rate increased due to increasing the area size of heat transfer. However, the overall heat transfer coefficient and pressure drop increased with decreasing the heat exchanger size (i.e., increased curvature ratio) due to the enhanced centrifugal force and inertia.

This study aimed to develop a solid self-nanoemulsifying drug delivery system (solid-SNEDDS) to enhance the formulation of ketoconazole (KTZ), a BCS Class II drug with poor solubility. Ketoconazole, which is insoluble above pH 3, requires solubilization for effective delivery. This SNEDDS comprises oil, surfactant, and co-surfactant, which spontaneously emulsify in the gastrointestinal tract environment to form nanoemulsions with droplet sizes less than 100 nm. The optimal SNE-vehicle composition of oleic acid, TPGS, and PEG 400 at a 10:80:10 weight ratio was determined based on the smallest droplet size achieved. This composition was used to prepare liquid SNEDDS containing ketoconazole. The droplet size and polydispersity index (PDI) of the resulting liquid SNEDDS were analyzed. Subsequently, solid-SNEDDS was fabricated using a spray-drying method with solidifying carriers such as silicon dioxide, crospovidone, and magnesium alumetasilicate. The physicochemical properties of the solid-SNEDDS were characterized by scanning electron microscopy and powder X-ray diffraction, and its solubility, droplet size, and PDI were evaluated. In particular, the solid-SNEDDS containing ketoconazole and crospovidone in a 2:1 weight ratio exhibited significantly enhanced solubility, highlighting its potential for improved medication adherence and dissolution rates.

The membrane structure should maintain the membrane materials in tension for structural stability guaranty. The anchoring part in the membrane structure is an important part. It has the function to introduce tension into membrane materials and function to transmit stress which membrane materials receives to boundary structure such as steel frames. In this paper, it grasps anchoring system of the anchoring part in the membrane structure concerning the fracturing characteristic condition of membrane structure, and the influence which is caused to yield it designates the stress state when breaking the membrane structure which includes the anchoring part and that stress transition mechanism is elucidated as purpose. This paper follows to previous paper, does 1 axial tensile test concerning the bolting part specimen, grasp of fracturing progress of the bolting part and the edge rope and hardness of the rubber, does the appraisal in addition with the difference of bolt tightening torque. As a result, the influence which the bolt anchoring exerts on the fracturing characteristics of the membrane material in the membrane structure anchoring part is examined.

This research investigated the immunoenhancing effect through the intracellular MAPKs and NF-B signaling pathways in macrophages activated by crude polysaccharides (YBP) of barley sprouts. YBP extracted from barley sprouts is composed of xylose (25.8%), arabinose (24.1%), galactose (23.4%), and galacturonic acid (11.7%). YBP did not affect the cytotoxicity and showed superior secretion of nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)- by RAW264.7 cells. Also, YBP dose dependently increased IL-6, TNF-, and inducible nitric oxide synthase (iNOS) mRNA gene expression. In the western blot, YBP strongly induced the phosphorylation of the p38, JNK, ERK, and IB pathways in RAW 264.7 cells. In the anti-pattern recognition receptor (anti-PRRs) assay, the effect of YBP on NO secretion strongly decreased toll-like receptor (TLR) 4 and Dectin1 antibodies, whereas IL-6 and TNF- secretion by YBP mainly decreased SR and CD14. Therefore, we concluded that YBPinduced NO, IL-6, and TNF- were secreted via the MAPKs, while NF-B pathways through TLR4, Dectin1, SR, and CD14 receptors existed in a macrophage surface and were involved in the immunoenhancing effect.

Hydrogen is considered as one of the most promising future energy carriers due to its noteworthy advantages of renewable and high calorific value. The long-term storage of liquid hydrogen with low heat leakage is essential for future deep space exploration. Because of low critical temperature and volatility, liquid hydrogen tank poses severe requirements to multi-layer insulation (MLI). In order to reduce heat leak into tank, vapor cooled shield (VCS) was set up to cool MLI by retrieving the heat of discharged cryogenic gas hydrogen. This paper presents an parametric study on insulation system in liquid hydrogen storage vessel with MLI and VCS. Thermal model was developed, and heat transfer analysis by varying VCS position was conducted. Temperature and heat flux distributions along time passing were derived, and effect of VCS position on insulation performance was investigated.

기어의 구조 안정성 및 치물림 성능을 분석하기 위하여 유한요소해석이 널리 사용된다. 본 연구에서는 스퍼 기어의 유한요소 모델 링 조건이 해석 결과 및 간소화 효과에 미치는 영향을 분석하였다. 기어 구조 해석의 간소화 방법으로 기어 몸체 및 잇수 간소화, 요소 망 생성 방식, 접촉 및 마찰 조건, 해석 조건 등을 선정하였다. 기어의 성능해석 지표로써 1주기의 기어 치물림 사이클 동안의 정전달 오차를 계산하였고, 간소화 지표로써 해석 소요 시간을 측정하였다. 유한요소해석을 통해 치물림 주기에 따른 접촉 응력 분포 및 변화 양상을 확인하였다. 모델링 조건에 따라 최대 전달 오차와 해석 소요 시간에 차이를 확인하고 원인을 분석하였다.