This letter presents a compact and cost-effective microstrip low-pass filter (LPF) based on the incorporation of coupled lines with an MLCC-loaded microstrip stub (MLCC-CL) for practical mobile applications. The primary concept of MLCC-CL structure is to induce the separation of transmission zeros (TZs) and increase their number, thereby resulting in wideband rejection with a compact filter footprint. An analytical method is developed for efficiently and systematically designing the proposed MLCC-CL LPF. A test vehicle targeting 2.4-GHz wireless mobile services is fabricated using PCB manufacturing technology. The proposed LPF achieves a low insertion loss of 0.37 dB at 2.4 GHz, a 20-dB rejection bandwidth spanning from 4.68 to 10.80 GHz, and an extremely compact size of 2.74 mm(2) (0.0014 lambda(2)(g)), providing suitability for practical applications.

Efficient solar energy production is significantly hindered by dust accumulation, which severely reduces the performance of solar panels. To overcome this issue, we developed a phase-controlled, wind-driven 3-phase rotational triboelectric nanogenerator (RTENG) integrated with an electrodynamic screen (EDS) for selfpowered, unidirectional dust removal. The RTENG generates high-voltage alternating current (AC) without the need for external power sources and uses a precisely phase-controlled 3-phase electrode configuration to produce a traveling electric field that drives dust particles in a single direction. This configuration enhances dust removal efficiency, particularly at low panel inclination angles. The phase-controlled 3-phase RTENG-EDS system achieved dust removal efficiencies of up to 83.48 % based on weight and 62.38 % based on surface coverage, outperforming conventional 1-phase systems by factors of 1.6 and 1.13, respectively. Furthermore, the system maintained high performance across various wind speeds and panel inclination angles. These results underscore the effectiveness of phase-controlled 3-phase RTENG technology in advancing self-powered solar panel cleaning systems and enhancing the overall efficiency of solar energy harvesting.

Maintaining the efficiency and longevity of solar panels relies on effective dust management. While electrodynamic screen (EDS) technology is a promising solution, its reliance on high-voltage power sources can compromise overall solar panel efficiency. In this study, we introduce an innovative approach that harnesses wind-driven rotating triboelectric nanogenerators (RTENGs) to power EDS systems, enabling autonomous dust removal from eco-friendly solar panels. We conducted precise optimizations of the RTENG's structure, electrode design, and the dielectric material of the EDS plate to maximize system performance. Our results establish a direct relationship between RTENG power output and solar panel performance, achieving efficiencies exceeding 90% at wind speeds of 28m/s. This research underscores the practical viability of triboelectric nanogenerators as a sustainable power source for dust management, offering profound implications for the field of solar energy harvesting.

Traditional Korean medicine can diagnose health condition through the tongue image using shapes and locations of cracks on the tongue. This paper proposes an algorithm that can classify tongue images according to shapes and locations of cracks. The proposed algorithm was developed using CNN with transfer learning and our computational result shows that the proposed algorithm can classify the tongue images effectively.

The Asian mantis, Hierodula patellifera, is a native species of South-East Asia and has been designated as a Korean Climate Biological Indicator Species. This study aimed to understand the responses of the phenology and distribution of H. patellifera to recent climate trends in South Korea as well as predictions for future responses. We constructed a combined dataset consisting of 1169 records ranging from 1984 to 2022. The number of records sharply increased over time and space, with citizen science data accounting for the greatest proportion. Our study confirmed the prolongation of the overall activity period of the Asian mantis over the past seven years caused by the advanced emergence and delayed senescence. The distribution range of the species also expanded towards higher latitudes and inland regions over the last 40 years. Species distribution models showed that temperature-related variables in the summer and winter seasons were the most critical factors influencing its distribution. In the future, suitable habitats for this species are predicted to expand across the entire Korean peninsula as temperatures rise based on the SSP climate scenarios. These results support the suitability of H. patellifera, which prefers warm environments, as a biological indicator of climate change. They suggest consistent monitoring under future climate warming. Our study also provides novel insights into the value of citizen science as a critical monitoring tool for detecting the impacts of climate change on ecosystems.

Welding is the most critical operation in the shipbuilding process and has a significant influence on the production cost and quality of ships. Therefore, the welding operation must be optimised. This paper presents a real-world welding gantry robot scheduling problem at shipyards, in which three gantry robots function in parallel. Welding gantry robots cannot cross each other and should operate over a certain distance to avoid collisions. To minimise the makespan, the welding tasks given by line segments should be evenly distributed among the three gantry robots. The welding tasks assigned to each robot should be optimally sequenced to minimise the completion time, including the waiting time required to prevent collisions with neighbouring robots. In addition, long welding edges are split, and the split small length edges are assigned to the gantry robots. This paper proposes a mixed-integer linear programming model, three-stage solution approach, and variable neighbourhood search algorithm to solve this problem. Experimental tests conducted on 20 real problem instances revealed that the proposed approach can reduce the makespan by 14% on average when compared with the conventional method.

Although efforts to improve the productivity of semiconductor fabs have mostly focused on processing machine scheduling, recent productivity drops due to insufficient automated material handling system (AMHS) resources have made the efficient control of AMHS a major issue in improving overall productivity. This study introduces a storage prioritization procedure (SPP) for the effective allocation of work-in-process (WIP) to storage devices is applied to a real-world 300 mm fab. The proposed SPP utilizes a minimum-cost flow-based model to generate priority lists of storage devices for wafer lot transfers after determining the push or pull strategy for each machine group. Experimental studies are conducted according to four simulation scenarios that demonstrate the superior performance of the SPP. The field application results verify the SPP performance in the real-world fab. The productivity improvement due to the SPP is estimated to be tens of million dollars during the two months of the study period.

The independent and relative importance of ten variables related to fire, site, and prefire vegetation affecting the initial regeneration after fires was analyzed using the Random Forest statistical technique. The technique supplemented with the decision tree method was developed. This study was performed in prefire Pinus densiflora-dominated forests affected by large-scale fires in Korea. Among the ten variables, the basal area of prefire resprouter trees showed an overwhelmingly high contribution on the postfire regeneration (model improvement ratio (MIR) = 1.00). Consequently, stands with a high abundance of the resprouters showed rapid regeneration. Site factors including elevation, aspect, and slope had an MIR of 0.71, 0.63, and 0.57, respectively, while those for flame ratio and burn severity were 0.39 and 0.20. We revealed that the legacy of prefire vegetation had the most significant effect on the initial regeneration of stands, while site-variables played a lesser role, and fire-variables such as burn severity had a relatively minor effect. This technique was an important tool for explaining ecological phenomena involving the simultaneous action of multiple factors. Understanding the priorities of factors affecting the fast regeneration would be useful in establishing a restoration plan in forests where soil erosion is an issue following a fire.

System-level electrostatic discharge (ESD) noise due to electromagnetic fields radiating from an ESD generator were measured and analyzed in a solid-state drive (SSD) storage system. The field sources of an ESD generator were efficiently modeled from the measured tangential magnetic fields in front of a ESD generator. The extracted field sources were incorporated into a full-wave solver, and the fields inside the disk-array enclosure (DAE) were simulated and validated by comparing to measured fields. The field source models of the ESD generator were then also utilized to predict transient ESD-induced noise voltages in a simplified SSD. Finally, the coupling mechanism and the effects of the DAE geometry were investigated.

This paper proposes a work-in-process (WIP) allocation approach to improve on-time transfers of a unified automated material handling system (AMHS) in a semiconductor fabrication facility (FAB). The real-time operation and control of the complex AMHS often cause delayed transfers of wafers to manufacturing machines and result in production loss. We introduce transfer-due-dates from storages to manufacturing machines to enhance the on-time transfers in the AMHS and develop a mathematical model to allocate the WIP to the optimized storage locations based on transfer- due-date. The simulation results demonstrate that the machine utilization as well as the AMHS capability for on-time transfers can be improved by assigning the wafers’ interim storage locations more appropriately.

Background In 2020, a categorized list of wetland preferences, major habitats, and life forms of 4145 vascular plant taxa occurring in the Korean Peninsula was published by the National Institute of Biological Resources. We analyzed the list and explored the distribution patterns of the five categorized groups according to wetland preference, along with the information on the major habitats and the life forms of the plants belonging to those categories. Results Out of 4145 taxa, we found that 729 wetland plant taxa (18%) occur in Korea: 401 obligate wetland plants and 328 facultative wetland plants. Among the 729 wetland taxa, the majority (73%) was hygrophytes and the remaining 27% was aquatic macrophytes. Furthermore, almost all of the wetland taxa are herbs; so, woody plants are only 4.7%. The 16 carnivorous taxa distributed in Korea were characterized as obligate wetland plants. Conclusions We expect the categorized information would promote understanding of the characteristics of the plant species and would be an important source for understanding, conservation, and restoration of wetland ecosystems.

Low‐temperature poly‐silicon thin‐film transistors (LTPS‐TFTs) on glass substrates in modular micro‐LED displays have metal electrodes which are externally exposed to connect LED chips and pads. This structure increases the risk of electrostatic discharge (ESD) from the external environment. Furthermore, glass substrates cause high visible light reflectance. To improve the ESD robustness and reduce visible light reflectance, a backplane structure with a black fine metal mesh is proposed. Modular micro‐LED displays with the proposed structure achieved the ESD tolerance higher than 8kV through the standard system‐level ESD test and reduced the average visible light reflectance by more than 80%.

Background Genus Quercus is a successful group that has occupied the largest area of forest around the world including South Korea. The acorns are an important food source for both wild animals and humans. Although the reproductive characteristics of this genus are highly variable, it had been rarely studied in South Korea. Therefore, in Seoraksan and Odaesan National Parks (i) we measured the acorn production of Quercus mongolica , an overwhelmingly dominant species in South Korea, for 3 years (2017–2019), (ii) evaluated the spatial-temporal variation of acorn production, and (iii) analyzed the effects of oak- and site-related variables on the acorn production. Results The annual acorn production of Q. mongolica increased 36 times from 1.2 g m −2 in 2017 to 43.2 g m −2 in 2018, and decreased to 16.7 g m −2 in 2019, resulting in an annual coefficient of variation of 104%. The coefficient of spatial variation was high and reached a maximum of 142%, and the tree size was the greatest influencing factor. That is, with an increase in tree size, acorn production increased significantly (2018 F = 16.3, p < 0.001; 2019 F = 8.2, p < 0.01). Elevation and slope also significantly affected the production in 2019. However, since elevation and tree size showed a positive correlation ( r = 0.517, p < 0.001), the increase in acorn production with increasing elevation was possibly due to the effect of tree size. The acorn production of Odaesan for 3 years was 2.2 times greater than that of Seoraksan. This was presumed that there are more distribution of thick oak trees and more favorable site conditions such as deep soil A-layer depth, high organic matter, and slower slopes. Conclusion As reported for other species of the genus Quercus , the acorn production of Q. mongolica showed large spatial and annual variations. The temporal variability was presumed to be a weather-influenced masting, while the spatial variability was mainly caused by oak tree size.

Background Most of the Pinus densiflora forests, occupying the largest area, have been restored in South Korea since the 1970s. As young pioneer forests, the succession process is under way. Since the forests are distributed nationwide and are vulnerable to disturbances, the process may differ depending on the geography and/or site conditions. Therefore, we reviewed the direction, the seral communities, and the late-successional species of progressive and disturbance-driven succession nationwide in the cool-temperate zone through meta-analysis and empirical observations. Main text As a result of a meta-analysis of the direct succession and vertical structure, we found that the P. densiflora forest is in a directionally progressive succession, changing to the broadleaved forest after forming a mixed forest with its overwhelming successor, Quercus species (particularly Q. mongolica and Q. serrata ). In dry stands in a relative sense, the Quercus species was favored occupying over 80% of the abundance of the succeeding species. Therefore, in dry stands, it is presumed that Quercus -dominated stage would last for a long time due to the current dominance and long life span, and eventually, it settles as Quercus -broadleaved forest with a site change. Contrary to this, it is presumed that in mesic stands where Quercus species do not occur or have low abundance, the late-successional broadleaved species settle early to form a co-dominant forest with multiple species. Due to geographical limits, the species composition of the two late-successional forests is different. Disturbances such as insect pests and fire retrogressed vulnerable P. densiflora forest for a while. However, it was mostly restored to the Quercus forest and is expected to be incorporated in the pathway of the dry stand. Conclusions We revealed the succession process of P. densiflora forests according to geography and moisture and found that stand moisture had a decisive effect on the species and abundance of the successor. Although the P. densiflora forest is undergoing structural changes, the forest is still young; so within a few decades, physiognomy is not likely to change. Therefore, the decrease in the forest area may be due to other causes such as disturbances and forest conversion rather than due to succession.

A structure embedded in a printed circuit board is proposed to control secondary discharge currents and improve the system-level electrostatic discharge (ESD) immunity for a mobile product with a metal frame. Noise voltages and discharge currents were measured and analyzed according to several secondary discharge paths, such as an air arc, a voltage suppressor device, and with the interlaced suppression device. ESD events that caused soft failures of a real commercial mobile product were tested while a high-definition video was playing. System-level ESD-induced noise and soft failures were cost effectively reduced by the interlaced suppression device.

The Tokyo Olympics held in 1964 opened the floodgates for a sporting rivalry between North and South Korea at the height of the Cold War. Although this keen competition would not take place on the field, the two Koreas carried out an ‘ideological battle’ to woo the Korean community in Japan, who were split by the pro-North Korean organization and the pro-South Korean organization. Deeply discontented by the ban imposed on a North Korean star athlete, the North Korean contingent withdrew from the Olympics at the last minute. Meanwhile, South Korea had the best record in its Olympic history at Tokyo, but this sporting accomplishment was completely dwarfed by the startling success of its former colonizer. In the wake of the Olympics, the public antagonism towards Japan reached its climax, mainly due to the treaty between Japan and South Korea in which the South Korean government sought to receive economic assistance rather than an official apology from Japan. Under these circumstances, the two Koreas would gear up for imminent sporting wars against each other and against Japan and the Western capitalist countries by restructuring their elite sports system under the banners of Chuche ideology in North and anti-communism coupled with anti-Japanese sentiments in South.

This paper presents a controller IC with on‐display capacitive sensor for touch and multi fingerprint function. Single sensor and the IC enable both touch and fingerprint without additional area or sensor. Fully balanced multi‐channel driving technique with proposed method removes column offset to maximize the immunity to display and external noise. Prototype IC is fabricated in a 65nm CMOS technology. This work achieves 31.6dB SNR with 0.7mmϕ stylus and 120Hz frame rate with 14x10 pixels TSP in touch mode, and 32dB SNR with 0.2mm cover glass and 200ms scan time in multi‐fingerprint mode with 5cmx3.5cm area.