This study quantitatively analyzed the target strength (TS) characteristics of the dotted gizzard shad (Konosirus punctatus) across various fork lengths (FL) and frequency conditions. In July 2023, TS measurements were conducted on six size groups (FL: 14.4–23.5 cm) under free-swimming conditions in a seawater acoustic tank at the Fisheries Resources Research Center in Tongyeong, Korea. A scientific echosounder (EK80, SIMRAD) was used to collect TS data at three frequencies: 38, 70, and 120 kHz. The results showed that TS values increased with fork length, and the 120 kHz frequency exhibited the widest distribution range and distinct bi- or multi-modal patterns. The TS–FL relationships for each frequency were as follows: TS38 kHz = 20·log(FL) ‒ 68.41, TS70 kHz = 20·log(FL) ‒ 70.76, and TS120 kHz = 20·log(FL) ‒ 70.90. Unlike traditional tethered measurement methods, this study obtained TS data under free-swimming conditions, providing values more representative of real-world acoustic survey environments. The findings are expected to serve as foundational data for improving the accuracy of monitoring the distribution and biomass estimation of K. punctatus using hydroacoustic methods.

Transparent and conducting SnO2 and SnO2/Ag/SnO2 (SAS) films were deposited on glass substrates by magnetron sputtering at room temperature. The effect of the SnO2 target power and Ag interlayer on the visible transmittance and electrical properties of the film was considered. Although all the SnO2 films had an amorphous structure under all sputtering power conditions, SnO2 films deposited at a target power of 60 W showed a lower resistivity of 2.25 Ω cm and a lower surface roughness of 1.4 nm. The average visible transmittance also varied with target power conditions. The average visible transmittance increased from 73.7 % (40 W) to 76.3 % (60 W) and then decreased to 73.2 % (80 W). When all films were compared, it was found that the SnO2 films deposited at 60 W had a higher figure of merit of 2.98 × 10-7 Ω-1. In addition, the SnO2 films with a Ag 10 nm interlayer showed a lower resistivity of 4.28 × 10-5 Ω cm and a visible transmittance of 70.58 %. The Ag interlayer in the SnO2 films increased the figure of merit to 7.88 × 10-3 without substrate heating or post-deposition annealing. The observed results confirm that the optical and electrical properties of SnO2 films can be enhanced by optimizing the sputtering target power condition and the thickness of the Ag interlayer, respectively.

This study compares four major Korean hate speech corpora to analyze differences in target group categorization and the impact of construction methods. The results show that the proportions of key target groups— gender, origin, physical traits, and ideology—vary greatly depending on how the corpus was compiled. In particular, keyword-based data sets revealed a notably higher focus on gender, with the influence of data collectors’ subjectivity and contemporary social issues clearly reflected. Furthermore, by analyzing the intersectionality and exclusivity of hate speech, we identified complex interconnections among target groups and challenges in classification arising from contextual usage. The study recommends the development of theme-specific and context-aware corpora to accurately capture these features.

This study aimed to measure the in-situ target strength (TS) of the moon jellyfish (Aurelia aurita) using a 200 kHz scientific echo sounder in a natural coastal environment. The acoustic survey was conducted in the coastal waters of Soho Port, Yeosu, Korea, from June 4 to 5, 2024. TS measurements were performed by installing the transducer in both horizontal and vertical orientations, and the TS distribution characteristics were analyzed. The measured TS values ranged from -89.8 to -64.8 dB in the horizontal direction and from -90.0 to -59.1 dB in the vertical direction, showing no significant difference between detection orientations (p<0.05). Additionally, a bell diameter-wet weight relationship for Aurelia coerulea was derived based on the specimens collected at the survey site. The empirical TS model proposed by Mutlu (1996) was applied to estimate TS values using the measured morphological data, and the results exhibited a similar trend to the field-measured TS distribution. These findings provide fundamental data for acoustic monitoring and stock assessment of jellyfish populations in natural environments.

국경 간 인수합병(Cross-border M&A)은 이중 조직 정체성과 다양한 제도적 환경을 관리하는 복잡한 통합 과제를 포함한다. 기존 연구들은 주로 국가 수준의 요인에 초점을 맞췄지만, 특히 자 회사의 경험과 같은 목표 기업의 특성에 대한 연구는 상대적으로 부족했다. 본 연구는 자회사 대 독립 기업, 국내 자회사 대 해외 자회사와 같은 다양한 목표 기업의 특성이 국경을 넘는 M&A에서 인수 기업의 주주 가치에 어떻게 영향을 미치는지 분석한다. 1994년부터 2012년까지의 국경을 넘 는 M&A 거래에 대한 이벤트 연구를 통해, 자회사의 경험이 인수 기업의 주주 가치를 증가시킨다 는 것을 발견했다. 그러나 제도적 거리가 증가할수록 국내 자회사의 경험 가치는 감소하는 경향이 있었다. 이러한 연구 결과는 국경을 넘는 M&A에서 자회사 경험의 중요성을 강조하며, 제도적 거 리가 그 효과를 어떻게 조절하는지를 보여준다. 이는 연구자와 실무자 모두에게 중요한 시사점을 제공한다.

High-frequency soft magnetic Ni, Fe, and Co-based thin films have been developed, typically as nanocrystals and amorphous alloys. These Ni, Fe, and Co-based thin films exhibit remarkably good frequency dependence up to high frequencies of several tens of MHz. These properties arise from the moderate magnetic anisotropy and fairly high electrical resistivity that result from the microstructural characteristics of the nanocrystalline and amorphous states. In this paper, Al-Co/AlN-Co and Al-N/AlN-Co multilayer films were deposited using two-facing-target type sputtering (TFTS). Their microstructures, magnetic and electrical properties were studied with the expectation that inserting Al-Co or Al-N as an interlayer could effectively reduce the coercive force and produce films with relatively high resistivity. A new approach is presented for the fabrication of Al-Co (Al-N)/AlN-Co multilayer films, prepared with the TFTS system. The deposited films were isothermally annealed at different temperatures and investigated for microstructure, magnetic properties and resistivity. The TFTS method used in this experiment is suitable for fabricating Al-Co(Al-N)/AlN-Co multilayer films with different layer thickness ratio (LTR). The annealing conditions, thickness of the multilayer film, and LTR can control the physical properties as well as the microstructure of the manufactured film. Magnetization and resistance increased and coercivity decreased as LTR decreased. The thin film with LTR = 0.175 exhibited high resistivity values of 2,500 μΩ-cm, magnetization of 360 emu/cm3, and coercivity of 5 Oe. Results suggests that thin films with such good resistivity and magnetization would be useful as high-density recording materials.

In this paper, the goal is to produce a target wheel that integrates the plate and CPS wheel among the components of the drive plate mounted on an automobile engine. We attempted to develop a manufacturing process technology for incremental forming of a target wheel with the desired thickness by rotating a disk-shaped thin plate material and deforming the plate using a forming device and tools. Incremental forming system was set up by establishing a forming process and designing and manufacturing the device and parts required for processing. It consists of a total of 4 stages of molding process, and the optimal roll design that can properly collect materials to prevent cracks or reverse steps at each stage is primarily important. After manufacturing the prototype, a material test was performed to confirm whether the mechanical properties of the deformed part were sufficient to make gear teeth.

Recently, domestic fishing production of Japanese horse mackerel has been continuously decreasing. To achieve sustainable fishing of this species, it is essential to acquire its target strength (TS) for accurate biomass estimation and to study its ecological characteristics. To date, there has been no TS research using a broadband echosounder targeting Japanese horse mackerel. In this study, for the first time, we synchronized an underwater camera with a broadband frequency (nominal center frequency of 200 kHz, range: 160-260 kHz) to measure the TS according to the body size (16.8-35.5 cm) and swimming angle of the species. The relationship between Japanese horse mackerel length and body weight showed a general tendency for body weight to increase as length increased. The pattern of the frequency spectra (average values) by body length exhibited a similar trend regardless of body length, with no significant fluctuations in frequency observed. The lowest TS value was observed at 243 kHz while the highest TS values were recorded at 180 and 257.5 kHz. The frequency spectra for the swimming angles appeared to be flat at angles of –5, 0, 30, 60, 75, and 80° while detecting more general trends of frequency spectra for swimming angle proved challenging. The results of this study can serve as fundamental data for Japanese horse mackerel biomass estimation and ecological research.