• Korean Journal of Applied Biomechanics
• /
• v.25 no.3
• /
• pp.241-248
• /
• 2015

Objective : The purpose of this study was to investigate the theta on the components of ground reaction force according to the ground conditions during gait. Method : Six healthy women(mean age: 22 yrs, mean height: $166.14{\pm}2.51cm$, mean body weights: $56.61{\pm}4.58kg$) participated in this study. The medial-lateral GRF(Fx 1), anterior-posterior GRF(Fy 1, Fy 2), vertical GRF(Fz 1, Fz 2, Fz 3), and impact loading rate were determined from time function and frequency domain. Also, GRF theta were time function and forces. Results : Fx 1, Fy 1 and Fy 2 of stair descending showed significant statistically higher forces than that of level walking, and ascending. Fz 1 of stairs descending showed significant statistically higher forces than that of level walking and stairs ascending(theta $88.62^{\circ}$). Also, Fz 2 of level walking showed significant statistically higher forces than that of stairs ascending and descending(theta $65.78^{\circ}$). Fz 3 of stairs ascending showed significant statistically higher forces than that of level walking and stairs descending($65.26^{\circ}$). Impact loading rate of stairs descending showed significant statistically higher forces than that of level and ascending walking. The GRF showed similar correlation with GRF theta(r=.603) according to the ground conditions during gait. Conclusion : These results suggest that the GRF theta can be used in conjunction with a gait characteristics, prediction of loading rate and dynamic stability.

• Ocean and Polar Research
• /
• v.25 no.4
• /
• pp.653-662
• /
• 2003

Changes in the area of geo-ecosystem $(62^{\circ}09'S,\;58^{\circ}31'w)$ reflect climatic changes in the South Shetland Islands. Air temperature and deglaciation will increase. The ice-free space area at the SSSS 8- (ASPA 121) site has enlarged threefold during the last 21 years, thus creating conditions for inhabitation and succession. Wind, water and snow play important roles in transportation of geochemical components. They distribute nutrients, mineral substances, seeds, fragments of plants and animals, etc. Plant and animal colonization is patchy and it happens at random in an 'island' - like manner. The colonization pattern is dependant, to a high degree on physical factors. The newly uncovered ice-free areas are at first inhabited by a vascular plant known as the Deschampsia antarctica. The border of the land-oasis with Admiralty Bay is the place where the processes related to animal feeding at the sea and reproduction on the land take place. Bird colonies and pinniped lairs form centers of fertilization surrounded by high chemical gradients dependent on the direction of the flow of nutrients $(e.g.\;NH_4)$. During the last 25 years, the numbers of penguins in this region have decreased, and thus the amount of materials excreted on land has diminished. The numbers of fur seals change in multi-annual cycles, and their migration into this area is related to the E1 $Ni\~{n}o$ phenomenon. The numbers of elephant seals in the area did not change. Organic matter deposited by the sea onto the shore are a source of nutrients and deficient chemical elements on land. Mineral matter is washed out into the waters of Admiralty Bay. These processes change seasonally, and multi annually. Negative effects on the environment at Arctowski Station induced by man are slight, but noticeable nevertheless. Physical processes have the largest influence on the living conditions and distribution of plants and animals, and as a consequence, on the functioning of the geo-ecosystem in the coastal-shore zone of the Maritime Antarctic.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.418-424
• /
• 2019

The present study investigated the effects of the moment arm length on balance and walking when carrying a backpack. In total, 30 normal adults without orthopedic and neurological injuries were assessed. For each subject, balance and gait were measured under three conditions: 1) the no backpack condition, 2) the general backpack condition, and 3) the decreased length of moment arm backpack condition. There were significant differences in the center of the pressure area and velocity between the three conditions, whereas there was no significant difference in the center of the pressure area and velocity according to the moment arm length. There were significant differences in double limb support time and walking velocity under the three conditions, and there was a significant difference only in double limb support time according to the moment arm length. The results of the present study showed that a change in the length of the moment arm can be helpful for walking when carrying a backpack.

• PNF and Movement
• /
• v.18 no.2
• /
• pp.265-273
• /
• 2020

Purpose: The purpose of the study was to investigate the effects of HMD (head mounted display)-based virtual reality balance training on static balance in young adults, and whether appropriate balance training can help healthy adults to improve balance ability in daily living. Methods: The study subjects were 14 healthy adults. Subjects received 20 minutes of HMD-based virtual reality balance training 3 times per week for 4 weeks. Static balance was measured before, during, and after training and after one month. Static balance was measured in a total of 8 conditions, and the results were classified as visual (F1), somatosensory (F5-6), vestibular (F2-4), and central nervous system (F7-8). Results: The test results showed no significant difference in pre-training, post-training, and follow-up results under all conditions at Fourier index F1, F5-6, and F7-8 frequencies. For the F2-4 frequency, there was a significant difference before and after training under NC (neutral head position, eyes closed, firm surface) and PC (neutral head position, eyes closed, elastic surface) conditions. The NC condition returned a significant decrease of F2-4 frequency in post-training testing as compared to pre-training, and the PC condition showed a significant decrease of F2-4 frequency between the pre-training and mid-training tests, and between the pre-training and post-training tests. Conclusion: These results indicate that HMD-based balance training can improve balance ability, even in normal adults, and seems especially effective for vestibular function training.

• Journal of the Korean housing association
• /
• v.18 no.4
• /
• pp.49-58
• /
• 2007

The purpose of this study were to make clear the present condition of indoor thermal and air environment by cooling in school classrooms and to analyze the relation of the living conditions with indoor environment. The measurements on physical elements and observations on living conditions were carried out in 6 classrooms of 3 middle or high schools. Measuring elements were indoor temperature, relative humidity, PM10 and $CO_2$ concentration. As results, the averages of indoor temperature each classrooms were $24.9{\sim}26.6^{\circ}C$. Most of classrooms were lower than the Maintenance standard $(26{\sim}28^{\circ}C)$ of School Health Law. The means of relative humidity were $51.3{\sim}72%$, all classrooms were ranged within the standard $(30{\sim}80%)$. The means of PM10 concentration were $3.5{\sim}23.1{\mu}g/m^3$, all classrooms were kept within the standard $(100{\mu}g/m^3)$. The means of $CO_2$ concentration were $1218.7{\sim}4705.4ppm$, all classrooms were exceed the standard (1,000ppm). The results of analysis on relations of living conditions with the physical elements are as follow; the air conditioner set of temperature, windows and doors opening elapsed time, the number of students in classrooms and activities of students had certain effect on indoor environment.

• Imaging Science in Dentistry
• /
• v.47 no.3
• /
• pp.199-207
• /
• 2017

Purpose: Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods: Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results: Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion: Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

• Human Ecology Research
• /
• v.55 no.2
• /
• pp.141-152
• /
• 2017

Recently, one-person households have surpassed nuclear families. One-person households are expected to have many problems with health due to an irregular life style and a tendency to be more isolated from society. In addition, we need to divide the generations and survey each generation due to differences in one-person household factors and characteristics as well as the unique physical conditions of each generation. Therefore, based on the sixth Korea National Health and Nutrition Examination Survey, this survey examined health behavior differences between one-person households and non-one-person households according to generation (respectively) as well as studied how one-person households and health behavior influence subjective health conditions. The major result of this survey is as follows. First, one-person households reveal a higher rate in the negative health behavior than non-one-person households. Second, the physical activity of all households reveals a high rate of non-activity. Third, health scores of one-person households are lower than that of non-one-person households; consequently, the analysis of health scores for one-person households and non-one-person households indicated that the middle age health scores for one-person households have been lowest in generations. Fourth, the factors that influence subjective health conditions indicated that one-person household and health behavior has meaningful influence; in addition, the subjective health condition of one-person households are lower than non-one-person households under controlled health behavior.

• Journal of the Korean Society for information Management
• /
• v.27 no.2
• /
• pp.173-199
• /
• 2010

The purpose of this study was to select the evaluation criteria for the physical spaces of a children's library in an effort to back up children's development in a more positive and constructive manner, as the physical spaces of a children's library are likely to affect their development. Theories of children's developmental characteristics were reviewed, and user benefit criteria were analyzed, which were the basis of the spatial conditions to facilitate their development in consideration of the developmental characteristics of different stages and domains. And then conceptual words that corresponded to the concept of benefit and commonly appeared in earlier studies of children's libraries and children's spaces were selected to embody the concept of benefit. 12 conceptual words were presented as corresponding words of benefit, out of which the majority were selected from among the previously selected words and some were added by this researcher. Several libraries were reviewed by the 12 standards, and a spatial criteria checklist for a children's library that focused on benefits provided to growing children was provided.

• Journal of the Korean Wood Science and Technology
• /
• v.25 no.4
• /
• pp.29-38
• /
• 1997

The effect and control of wood property of reconstituted composite panels for improved board properties by wood-waste materials and development of combination method for heterogeneous materials have been of interest to the wood science researchers. The purpose of this study is to consider the properties in relation to hot pressing conditions and to develope the optimum hot pressing condition with waste wood and waste tire for the manufacturing of composite boards. The study of composite boards for recycling of wood and waste tire is nothing up to the present. Physical and mechanical properties such as specific gravity, moisture content, swelling coefficient, modulus of rupture and modulus of elasticity in bending test were studied. The condition of 3-stage press time for the lowest moisture content of composite board was $4{\rightarrow}3{\rightarrow}3$ minutes. Specific gravity of composite panels was affected mainly by the amount of rubber chip. Because of the low rigidity and high elasticity in rubber chip, it is considered the composite panel was adequate material in the place of compression load, but not bending load. Therefore, it was concluded that a use of rubber-based wood composite panel is proper to the interior materials such as floor a room than exterior materials. From the test results, the most optimum hot pressing conditions were $4{\rightarrow}3{\rightarrow}3$ minutes for 3-stage press time and $45{\rightarrow}20{\rightarrow}5kg/cm^2$ for 3-stage press pressure. The rubber-based wood composite panel was very excellent in elasticity by combination of rubber chip in comparison with existing other wood-based materials. Therefore, it was considered that rubber-based wood composites can be applicable to every interior materials such as floor a room and will be expected to effective reuse and recycle of waste tires and wood-waste materials, and will be contribute to protection of environment pollution in earth.

• The Journal of Korean-Japanese National Studies
• /
• no.33
• /
• pp.67-111
• /
• 2017

This article aims to shed light on the wartime labor mobilization of prisoners on a large scale in/across colonial Korea and beyond during the late wartime period. More specifically, this article reveals the logic and mode of mobilization, and sorts out nationwide mobilization cases in colonial Korea. To this end, this article draws on documents and magazines published by the criminal administration of the Japanese Government-General of Korea, as well as the memoirs of prisoners and prison staff including prison administrators and prison chaplains. With the onset of the wartime system, the labor work in prisons centered on the production of military supplies. In 1943, the labor mobilization began to organize the National Protection Corps and dispatch them to remote workplaces. For example, at the requests of the military, prisoners were selected and sent to Hainan Island, while others were sent to military factories and mining fields in the northern part of the country. The authorities specified and adjusted the criteria for imprisonment based on education, physical strength, and other physical and mental conditions. Unconverted ideological offenders were excluded from the mobilization, and instead put under separate control. In preparation for mobilization, the prisoners trained in military drills, received Japanese language education, and underwent assimilation as imperial subjects through the preaching in prison. In order to induce prisoners to volunteer, a legislation system based on the shortening of the prison terms, including the parole system, was also promoted under the wartime system. As a result, prisoners were forced to work harder and faster even under the lowest of wages, poor food and poor housing conditions, and they also filled vacancies in managerial positions by serving as supervisory assistants. The reward system for them, however, did not function properly towards the end of the war, and the number of escapes and infectious outbreaks, as well as mortality rates rapidly increased under the harsh conditions.