This study proposes a novel methodology for quantitatively evaluating the contribution of input signals in the time domain using Mutual Information (MI). Traditional contribution analysis methods based on Pearson correlation coefficients are limited by their assumption of linearity, making them inadequate for systems with time-varying characteristics or nonlinear transfer paths. To address this, we construct simulation data comprising transient, non-stationary input signals and nonlinear transfer functions, and compute time-local mutual information by adopting the windowing approach commonly used in Short-Time Fourier Transform (STFT). The results demonstrate that the proposed MI-based method outperforms conventional linear techniques in capturing the contributions of inputs under nonlinear and time-varying conditions. Notably, the MI approach provides accurate quantitative assessment even when the system's transfer path responds nonlinearly to input amplitude. This study shows that MI-based contribution analysis is a powerful and effective tool for evaluating input influence in nonlinear, non-stationary, and multi-input systems, and lays a foundation for future applications to experimental data and integration with alternative MI estimation methods.

본 연구는 새만금 5개 지점(동진, 가력, 만경, 신시, 계화)의 1시간 간격 수질 시계열 자료를 활용하여 수질 항목 간 인과구조와 변수 중심성을 정량적으로 분석하였다. 이를 위해 상관분석, Granger 인과성, DirectLiNGAM, 중심성 분석을 적용하였다. 상관분석에서는 전 지점에서 수온–DO 간 음의 상관과 염분–DO 간 양의 상관이 공통적으로 나타났으나, 영양염–DO 관계는 지점별 차이를 보였다. Granger 분석은 전반적으로 양방향 연결이 우세했으나, 동진·만경(하천)에서는 수온·탁도·염분이 영양염 및 유기물 지표를 선행하였고, 계 화(기수역)에서는 담수·해수 요인이 결합된 혼합 구조가 드러났다. LiNGAM 분석에서는 동진·만경에서 수온·탁도가 중심 노드로, 계화에 서는 T-N과 TOC가 매개자로, 가력·신시(배수갑문)에서는 DO가 핵심 변수로 확인되었다. 종합하면, 새만금 수질 네트워크는 하천 지점에 서는 유기물 부하 중심, 기수역에서는 질소·유기물의 혼합 중심, 해수유통 지점에서는 DO 중심의 구조가 형성되어 있음을 보여주었다. 이 러한 결과는 새만금과 같은 반폐쇄성 연안에서 수질 항목 간 물리·화학적 인과 메커니즘을 정량적으로 해석하는 데 기여하며, 향후 수질 개선을 위한 조절 변수 선정, 예측 모델 구축, 실시간 관리 전략 수립에 과학적 근거를 제공할 수 있다.

This study was conducted to investigate the residue pattern in milk of tetrachlorvinphos oral product used in dairy cows and to suggest an appropriate withdrawal period for the tetrachlorvinphos oral product in milk. The oral product containing tetrachlorvinphos was administered per oral to Holstein dairy cows at a dose of 3.4 g of the active ingredient per 100 kg body weight (maximum dose). Milk was collected at 12-hour intervals during administration and up to 120 hours after termination of administration to determinate tetrachlorvinphos residue in milk by LC-MS/MS. Tetrachlorvinphos residues at each time point and the maximum residue level for tetrachlorvinphos in milk (0.01 mg/kg) were applied to a non-statistical model to establish the withdrawal period of the test product. The recovery, precision, coefficient of determination(R2), limit of detection (LOD) and limit of quantitation (LOQ) of the analytical methods used to quantify tetrachlorvinphos were 98%~104%, 5%~11%, 0.9981~ 0.9991 and 2 μg/kg, 7 μg/kg, respectively. These parameters met all the method validation criteria suggested by the Ministry of Food and Drug Safety and were used as an analytical method for tetrachlorvinphos in milk. When this product was administered to dairy cows at 1x dose by feeding, the tetrachlorvinphos was undetectable in milk (below the limit of detection) in all cows during the dosing period and up to 120 hours after termination of administration. Therefore, we suggest the withdrawal period of this product in milk as 0 days.

The Pyrosim fire simulation program was used to investigate changes in operating time as a function of the attachment height of a fixed-temperature detector. Operating times were analyzed for detector heights ranging from 4 m to 7.5 m, in 0.5 m increments, within a 30 m2 space. The fire source was modeled as a wooden pallet 1.22 m in height, and a Type 1 fixed-temperature detector with an activation temperature of 67.9℃ was used. The simulation results showed that operating time increased progressively with detector height, rising from 155.7 seconds at 4m to 206.3 seconds at 7.5 m a maximum delay of 50.6 seconds. Notably, larger increases were observed in the 4 m ~ 4.5 m and 6 m ~ 6.5 m ranges 14.9 and 11.5 seconds, respectively than those observed in other intervals. This suggests that critical height ranges should be considered when establishing detector installation standards. This study found that current design standards may not ensure adequate detection performance in high-ceilinged structures. In warehouses and industrial facilities with ceilings of 6m or higher, such delays in detector activation could hinder early detection, indicating a need for improvements

This study quantitatively analyzed the effect of ceiling height on the response time of rate of rise heat detectors. A 7 m × 5 m simulation model was constructed using the PyroSim program, and scenarios were conducted by varying the installation height from 4.0 m to 7.5 m in 0.5 m increments. A wooden pallet fire source, placed at a height of 1.22 m, was simulated. The simulation results showed that as the installation height increased, the response time was delayed from 155.6 seconds to 204.6 seconds a difference of approximately 49 seconds. Meanwhile, the activation temperature decreased from 50.4 ℃ to 43.4 ℃, representing a drop of about 7 ℃. These findings indicate that in structures with higher ceilings, the responsiveness of detectors may be compromised due to the delayed arrival of hot air flows. Therefore, current height based installation standards in prescriptive design should be re-evaluated for high ceiling structures. Complementary design measures such as optimized placement, detector type selection, and increased installation density are recommended.