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Abstract In an experimental exploration, we successfully implemented a self-assembling methodology to construct a periodic liquid-air structure inside a hollow optical fiber (HOF). This fiber comprises a central air hole, a germanosilica ring core, and a silica cladding. A periodic structure of liquid droplets and air was obtained by the application of a microscopic heat source (MHS) traversing along the axial direction of the liquid-filled HOF. In the course of this study, we discerned three distinct zones within the structure. The first zone, referred to as Zone 1, demonstrated near-constant periodicity. The second zone, Zone 2, exhibited adaptable properties with regard to its periodicity, allowing it to be flexibly controlled. In the third zone, Zone 3, we noticed a chaotic response to external parameters, including temperature and the speed at which MHS was traversed. To regulate the liquid-air periodic structures, two different types of MHSs were utilized - a micro hydro-oxygen torch and a metal ring heater, each mounted on a translation stage. The study provides a detailed account of the parameters employed in utilizing these MHSs. Additionally, the optical properties of these liquid-air periodic structures were meticulously analyzed to explore the potential for developing new optofluidic applications.

ObjectivesThis study aimed to examine age-related differences in the comprehension of Korean comparative sentences with varying word orders by employing both offline and online measures, and to investigate how variations in word order affect sentence processing across different age groups.MethodsA total of 52 monolingual native Korean speakers, 26 young adults, and 26 older adults, completed a sentence-picture-matching task under two word order conditions: comparative-first and nominative-first. Offline measures included accuracy and response time, while an online method involved eye-tracking within the Visual World Paradigm. Data analyses were performed using linear and generalized linear mixed-effects models.ResultsOlder adults demonstrated lower accuracy and longer response times compared to younger individuals. Distinctive fixation patterns were observed, particularly in the sentential-final phrase, across different age groups. Specifically, nominative-first sentences elicited greater target advantage scores among younger adults, whereas older adults showed higher scores in comparative-first sentences.ConclusionThe study highlights the potential of comparative sentences in elucidating age-related changes in sentence comprehension. These differences were evident not only in offline tasks but also in real-time processing, as evidenced by eye-tracking data. The findings suggest distinct processing strategies employed by young and older adults and underscore the importance of considering both syntactic and semantic cues in sentence comprehension.

Faces and bodies both provide cues to age and cuteness, but little work has explored their interaction in cuteness perception. This study examines the interplay of facial and bodily cues in the perception of cuteness, particularly when these cues convey conflicting age information. Participants rated the cuteness of face–body composites that combined either a child or adult face with an age-congruent or incongruent body alongside manipulations of the head-to-body height ratio (HBR). The findings from two experiments indicated that child-like facial features enhanced the perceived cuteness of adult bodies, while child-like bodily features generally had negative impacts. Furthermore, the results showed that an increased head size significantly boosted the perceived cuteness for child faces more than for adult faces. Lastly, the influence of the HBR was more pronounced when the outline of a body’s silhouette was the only available information compared to when detailed facial and bodily features were presented. This study suggests that body proportion information, derived from the body’s outline, and facial and bodily features, derived from the interior surface, are integrated to form a unitary representation of a whole person in cuteness perception. Our findings highlight the dominance of facial features over bodily information in cuteness perception, with facial attributes serving as key references for evaluating face–body relationships and body proportions. This research offers significant insights into social cognition and character design, particularly in how people perceive entities with mixed features of different social categories, underlining the importance of congruency in perceptual elements.

We examined the relationships between mathematics achievement and collaborative problem solving, which has been emphasized as the 21st century skills. Focusing on moderating effects of attitude toward working with others, we analyzed the PISA 2015 data for binational comparison between Korean and the U.S. Random-intercept linear models - where the intercepts vary across schools while slopes are fixed across schools - were applied to the data including 5,545 students in Korea and 5,564 in the U.S. The findings showed the positive linear relationships between mathematics achievement and collaborative problem solving as expected, but the slope was remarkably higher in the Korean model. However, we found no significant moderating effects of attitude toward working with others on the relationship between mathematics achievement and collaborative problem solving. Particularly, students in Korea and the U.S. are likely to have similarly low scores in mathematics achievement when their collaborative problem solving scores are low. However, Korean students would have even higher mathematics achievement scores if students in Korea and the U.S. have similarly high collaborative problem solving scores. The findings suggest the necessity for further scrutinies on attitude toward working with others and research on teaching and learning the 21st century skills in an integrated way.

We investigated how the opportunity to learn (OTL) with different types of mathematics tasks are related to mathematical literacy and the role of perceived control in the relationship between OTL and mathematical literacy. The structural equation modeling was applied to the data of 1,649 Korean students from the PISA 2012 database. OTL with the four different types of tasks – algebraic word problems, procedural tasks, pure mathematics reasoning, and applied mathematics reasoning – were measured via student survey on how often they have encountered each type of task in their mathematics lessons and tests. The results showed that OTL with the procedural tasks was likely to increase mathematical literacy directly and indirectly through internal perceived control. Engaging in the applied reasoning tasks is positively related to external perceived control, but negatively to mathematical literacy.

Abstract For a positive integer k, let F ( q ) k : = ∏ n ≥ 1 ( 1 − q n ) 4 k ( 1 + q 2 n ) 2 k = ∑ n ≥ 0 a k ( n ) q n $$ F (q)^{k}:= \prod_{n \geq 1} \frac{(1-q^{n})^{4k}}{(1+q^{2n})^{2k}} = \sum_{n\geq 0} \frak{a}_{k} (n)q^{n} $$ be the eta quotients. The coefficients a 1 ( n ) $\frak{a}_{1} (n)$ can be interpreted as a certain kind of restricted divisor sums. In this paper, we give the signs and modulo values for a 1 ( n ) $\frak{a}_{1} (n)$ and a 2 ( m ) $\frak{a}_{2} (m)$ and calculate several convolution sums involving a k ( n ) $\frak{a}_{k} (n)$ .

Abstract The purpose of this research is to gather empirical evidence for attribution theory (Weiner in J Educ Psychol 71(1):3–25. https://doi.org/10.1037/0022-0663.71.1.3, 1979) to explain students’ feelings of helplessness when learning mathematics. The relationships between mathematics literacy in PISA 2012 and learned helplessness were also observed. Korean and Finnish students’ responses were analyzed with ordinal and linear regression analyses. Similar patterns were found between the two countries when students attributed their failure to either ability or task difficulty, but different relationships were found for other attributions. The findings indicated necessity of cultural factors in addition to the attribution theory to understand students’ helplessness in learning mathematics better.

Herein, we prepared 1,3-dipalmitoyl-2-oleoyl glycerol (POP)-rich fats with reduced levels of diacylglycerols (DAGs), adversely affecting the tempering of chocolate, via two-step hexane fractionation of palm stearin. DAG content in the as-prepared fats was lower than that in POP-rich fats obtained by previously reported conventional two-step acetone fractionation. Cocoa butter equivalents (CBEs) were fabricated by blending the as-prepared fats with 1,3-distearoyl-2-oleoyl glycerol (SOS)-rich fats obtained by hexane fractionation of degummed shea butter. POP-rich fats achieved under the best conditions for the fractionation of palm stearin had a significantly lower DAG content (1.6 w/w%) than that in the counterpart (4.6 w/w%) prepared by the previously reported method. The CBEs fabricated by blending the POP- and SOS-rich fats in a weight ratio of 40:60 contained 63.7 w/w% total symmetric monounsaturated triacylglycerols, including 22.0 w/w% POP, 8.6 w/w% palmitoyl-2-oleoyl-3-stearoyl-rac-glycerol, 33.1 w/w% SOS, and 1.3 w/w% DAGs, which was not substantially different from the DAG content in cocoa butter (1.1 w/w%). Based on the solid-fat content results, it was concluded that, when these CBEs were used for chocolate manufacture, they blended with cocoa butter at levels up to 40 w/w%, without distinctively altering the hardness and melting behavior of cocoa butter.

Due to the recent growth of the Internet and the rapid development of information and communications technology, the number of data centers and the amount of power consumed are expected to increase rapidly. However, these data centers consume large amounts of electric power throughout the year, regardless of working days or holidays; hence, measures to save energy at these facilities are urgently required. A numerical analysis was conducted in this study by changing various variables to examine the effects of various design and operating conditions on outdoor air-cooling systems and to derive some operating plans to minimize electric power consumption through the introduction of outside air into the computer room. When designing the system, it is desirable to select airflow considering various factors, such as the heat generated by the computer equipment, the efficiency of the fan, and the performance of the refrigerator, rather than the theoretical maximum outdoor airflow. As a result, the optimal design air volume was calculated according to the equipment load. Consequently, the optimal design air volume of the modeled computer system was obtained as 26,200 m3/h. The application of this optimal design air volume is expected to yield an annual energy-saving effect of 56.1% compared with the power consumption in the air-conditioning period during which the application of outdoor air cooling is impossible.

Geothermal source heat pump (GSHP) systems as renewable energy systems are being more frequently installed as part of the zero-energy building drive. However, in South Korea, where a large amount of heating load can be required, maintaining high system performance by using only a GSHP is difficult owing to the gradual degradation of its thermal performance. The performance of a solar-assisted GSHP system was therefore experimentally analyzed and compared with a GSHP-only system. The results showed that the heating coefficient of performance of the GSHP-only operation was 5.4, while that of the solar-assisted GSHP operation was 7.0. In the case of the GSHP-only system, the maximum temperature of the heat pump water supply on the heat source side was initially 13.1 °C, but this rapidly decreased to 11.4 °C during operation. For the solar-assisted GSHP system, the temperature of the water supply to the heat source side of the heat pump was controlled at 15–20.9 °C, and the power consumption for system operation was reduced by about 20% compared with that for the GSHP-only system. Much higher temperatures could be supplied when solar heat is used instead of ground heat, as solar heat contributes to the performance improvement of the heat pump system.

The recent expansion of the internet network and rapid advancements in information and communication technology are expected to lead to a significant increase in power consumption and the number of data centers. However, these data centers consume a considerable amount of electric power all year round, regardless of working days or holidays; thus, energy saving at these facilities has become essential. A disproportionate level of power consumption is concentrated in computer rooms because air conditioners in these rooms are required to operate throughout the year to maintain a constant indoor environment for stable operation of computer equipment with high-heat release densities. Considerable energy-saving potential is expected in such computer rooms, which consume high levels of energy, if an outdoor air-cooling system and air conditioners are installed. These systems can reduce the indoor space temperature by introducing a relatively low outdoor air temperature. Therefore, we studied the energy-saving effect of introducing an outdoor air-cooling system in a computer room with a disorganized arrangement of servers and an inadequate air conditioning system in a research complex in Korea. The findings of this study confirmed that annual energy savings of up to approximately 40% can be achieved.

The multi-temporal scales of two physical characteristics (areas and occurrence time) of the Ross Sea Polynya (RSP) in Antarctica were analysed using a sea-ice concentration data set (1979–2014) derived from the Scanning Multichannel Microwave Radiometer, the Special Sensor Microwave Imager and Sensor Microwave Imager Sounder. Then, the Ensemble Empirical Mode Decomposition (EEMD) was applied to the data sets to decompose signals into finite numbers of intrinsic mode functions and a residual mode: long time trend. This approach allowed us to understand the long-term variability of the RSP area and occurrence in response to atmospheric forcing through teleconnections between low and high latitudes by comparing the Nino3.4 and Southern Annular Mode (SAM) indices. The nonlinear trend of the RSP areas derived from the EEMD residual had an upward trending shift in the early 1990s and was fairly consistent with the nonlinear trend of Nino3.4. However, the trend of RSP occurrence time progressively increased and had a significant effect on the long time scale. The trend of the RSP area is significantly correlated (+0.98) with the ratio of the trend of the meridional to zonal wind components related with the nonlinearity of Nino3.4, suggesting that meridional wind stress dominated the changes of the polynya area in the Ross Sea. In addition, the nonlinear trends between the SAM and RSP occurrence time show a strong positive correlation, contributing to the earlier onset of polynya expansion and delayed connection with the open ocean owing to enhanced southerly winds.

The genetic relationships among 27 watermelon cultigens (Citrullus lanatus var. lanatus) from different countries of origin and with different horticultural characteristics and 5 related wild-type species and subspecies (Citrullus colocynthis, Citrullus lanatus var. citroides, and Citrullus rehmii) were assessed using amplified fragment length polymorphism (AFLP) and expressed sequence tag-simple sequence repeat (EST-SSR) markers. AFLPs were evaluated using 16 EcoRI-MseI primer combinations, and 862 alleles (an average of 53.8 alleles per primer combination) were scored. Polymorphisms were found in 806 (93.4%) alleles, whereas 56 monomorphic alleles were identified. Using 16 EST-SSR primer sets, 103 alleles were scored, and all 103 alleles were polymorphic among the 32 genotypes with an average of 6.4 polymorphic alleles per primer pair. However, the high polymorphic ratio among the AFLPs and EST-SSRs was largely due to the wild-type species, while little diversity was observed among the adapted cultivars. Genetic similarity coefficients were calculated based on the 965 polymorphic AFLP and EST-SSR alleles, and a phenetic tree was constructed. The dendrogram contained 2 major clusters. Cluster I included all adapted watermelon cultivars, and the similarity among these cultigens was very high (0.94-0.98), demonstrating cross relationships and a narrow genetic background. Cluster II was composed of 4 wild-type species. The genetic distance between the nodes that comprise these 2 clusters was approximately 0.63, indicating a high level of genetic dissimilarity between the adapted watermelon species and the other related species. The low level of marker polymorphism among the adapted cultivars implies that a severe bottleneck in genetic diversity existed in watermelon during the initial breeding practices.

Ralstonia solanacearum causes one of the most common soil-borne vascular diseases of diverse plant species, including many solanaceous crops such as tomato and pepper. The resulting disease, bacterial wilt (BW), is devastating and difficult to control using conventional approaches. The aim of this study was to investigate the differentially expressed genes in pepper root systems in response to infection by R. solanacearum. DNA microarray (Capsicum annuum 135K Microarray v3.0 Gene Expression platform) analyses were performed using a susceptible genotype, ‘Chilbok’, and a resistant genotype, ‘KC350’, at 3 time points (1, 3, and 6 days post inoculation). It has been identified 115 resistance-specific genes (R-response genes) and 109 susceptibility-specific genes (S-response gene), which were up-regulated in 1 genotype, but down-regulated in the other genotype. Gene Ontology (GO) analysis for functional categorization indicated that many R-response genes were related to genes that function in xyloglucan biosynthesis and cell wall organization, while S-response genes were involved in the response to stress and cell death. The expression of genes encoding xyloglucan endotransglycosylase/hydrolase (XTH) and β-galactosidase were verified by real-time RT-PCR at an early time point of R. solanacearum infection. The results supported the idea that rapidly induced XTH expression in ‘KC350’ may play an important role in the restructuring and reinforcement of the cell wall and restrict bacterial movement in xylem vessels. In addition, induced expression of β-galactosidase in R. solanacearum-infected ‘Chilbok’ implied that degradation of the cell wall structure in vascular tissues by β-galactosidase might be an important factor facilitating R. solanacearum invasion of and movement in susceptible host plants.

In response to the need to improve energy-saving processes in older buildings, especially residential ones, this paper describes the potential of a novel method of disaggregating loads in light of the load patterns of household appliances determined in residential buildings. Experiments were designed to be applicable to general residential buildings and four types of commonly used appliances were selected to verify the method. The method assumes that loads are disaggregated and measured by a single primary meter. Following the metering of household appliances and an analysis of the usage patterns of each type, values of electric current were entered into a Hidden Markov Model (HMM) to formulate predictions. Thereafter, the HMM repeatedly performed to output the predicted data close to the measured data, while errors between predicted and the measured data were evaluated to determine whether they met tolerance. When the method was examined for 4 days, matching rates in accordance with the load disaggregation outcomes of the household appliances (i.e., laptop, refrigerator, TV, and microwave) were 0.994, 0.992, 0.982, and 0.988, respectively. The proposed method can provide insights into how and where within such buildings energy is consumed. As a result, effective and systematic energy saving measures can be derived even in buildings in which monitoring sensors and measurement equipment are not installed.

I investigated the relationships between mathematics achievement on the Iowa Assessments and the mastery of four epistemic actions: selecting, analyzing, computing, and representing. These epistemic actions play a crucial role in characterizing mathematical reasoning and are essential for solving mathematics problems in the Iowa Assessments across different grade levels. The data analyzed included 16,644 fourth graders and 9,747 fifth graders from 2006 to 2012. The study employed the generalized DINA (deterministic inputs, noisy "and" gate) and linear regression modeling techniques. The findings of the study demonstrate a significant correlation between the mastery of the four epistemic actions and overall performance on the assessments. However, the degree of contribution from each epistemic action varied. Notably, the results indicate that fifth graders who have mastered the actions of selecting and computing are more likely to achieve high mathematics scores, regardless of their mastery levels in other epistemic actions. These findings have important pedagogical implications. It is crucial for elementary students to engage in diverse types of reasoning at early stages. However, considering the gradual development of reasoning abilities, early mastery of selecting and computing can potentially benefit students' high achievement in grades 4 and 5. By prioritizing the development of these specific skills, educators can support students in their mathematical growth and improve their overall performance on the assessments.