• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.10
• /
• pp.871-876
• /
• 2016

Abnormal odor similar with burning smell often appears at the cockpit in the beginning of ultra-sonic aircraft without air filter due to the heating of production materials remained at the bleed air duct. Sources of the odor should be removed by burn-in test before test flight in order to prevent pilot confuses order with emergency such as fire of engine. However, the present method cannot prevent abnormal odor completely at the high altitude flight because maximum temperature of flight is higher than it of burn-in-test. This paper suggests burn-in test improved based on the analysis of thermal conditions of high altitude flight. It is verified that the existing burn-in test cannot cover thermal conditions of high altitude flight due to the discontinuous flow control, high change rate of temperature per unit time and difference between limit temperature of condenser and turbine. In order to overcome the limitations of current methods, the new burn-in test with continuous flow control are suggested. The continuous flow control are achieved by ram air inlet control. The effect of suggested method are verified by ground tests and flight tests. The results show the bleed air temperature can cover the temperature of high altitude flight and prevent abnormal odor at the flight test.

• Journal of architectural history
• /
• v.2 no.1 s.3
• /
• pp.25-41
• /
• 1993

This study was made to analyze the housing adjustment phenomenon in the first half of Chosun Dynasty by applying Microsociological approach. By reviewing the housing adjustment theory of Morris and Winter, research model for the period was developed in terms of socioeconomic characteristics, normative housing deficit (=cultural norm-housing condition+family norm), constraints, behavioral propensities, and housing adjustment mechanism with the following results : 1. In the first half of Chosun Dynasty the size of the house, the house site and decorating items were specified by law (cultural norm) according to the social status. Although the law was constraints for the housing phenomenon, it was not applied universally. Frequantly the law was violated by the upper class. By the middle of the Dynasty the family norm became more important for the housing phenomenon than the cultural norm. 2. Efforts were made to practice the Confucianism as a cultural norm in the first half of Chosun Dynasty At that time Husband-Living-in-Wife's-House was more popular than Wife-Living-in-Husband's-House. Because the customs were against the Confucianism, the latter was encouraged by law. But it did not change. Instead a compromised system became popular in the middle of the Dynasty. The house shrine was practiced to increase the symbolism of the family, which, in turn, exerted influences in deciding the housing site (cultural norm). These cultural norm was not accepted as the family norm untill the second half of the Dynasty. These trends forced the man and woman use separate areas of the house, and formulated a hierarchic positions within a house. 3. It was shown that the settlement of Confucianism as a family norm was closely related to the popularization of the Ondol system in the house, which functioned as one of the behavioral propensities to encourage diversity of space for many purposes. Though the Ondol system was accepted as a useful heating system earlier, this became more popular in the middle of the Dynasty because the housing pattern with Ondol fitted very well with a large family system with patriarchism. Ondol system for one or two rooms substituted Ondol for all rooms in the second half of the Dynasty. 4. From the beginning of the Dynasty housing adjustment of the family was determined by the social status and by law (cultural norm). Within this cultural norm each family decided its adjustment mechanism according to its economic ability (family norm). Family norm was more important factor than the cultural norm to determine the micro-space pattern in the house. But this period witnessed the formations of new conditions by the ruling class's efforts to implement new ethics for hierarchy and sexual discrimination. According to these conditions the Confucianism overruled the family norm in the later period.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.3
• /
• pp.503-515
• /
• 2017

Underground structures that have recently become larger are required to be stable not only during normal times but also during earthquakes. Especially, it is very important to maintain the stability of the subsea tunnels during the earthquake. The objective of this paper is to verify the effectiveness of the flexible segment, which is one of the breakthrough facilities to maintain the stability of the subsea tunnel during the earthquake using the shaking table test. Another goal of this paper is to propose the optimum position of the flexible segment through 3D dynamic numerical analysis based on the verified results from shaking table tests. The 1g shaking table test considering the similarity ratio (1:100) to the cross section of the selected artificial subsea tunnel was carried out considering the Geongju and Artificial seismic waves, longitudinal and lateral wave, and with/without flexible segments eight times or more. As a result of the shaking table test, it was confirmed that the flexible segment is effective in improving the seismic performance of the undersea tunnel in all the experimental results. In addition, 3D dynamic numerical analysis was performed to select the optimum position of the flexible segment which is effective for improving seismic performance. As a result, it was confirmed that the seismic acceleration is attenuated when the flexible segment is installed adjacent to the branch section in subsea tunnel.

• Tunnel and Underground Space
• /
• v.24 no.2
• /
• pp.155-165
• /
• 2014

Multiple thermal energy storage (TES) caverns can be used for storing thermal energy on a large scale and for a high-aspect-ratio heat storage design to provide good thermal performance. It may also be necessary to consider the use of multiple caverns with a reduced length when a single, long tunnel-shaped cavern is not suitable for connection to aboveground heat production and injection equipments. When using multiple TES caverns, the separation distance between the caverns is one of the significant factors that should be considered in the design of storage space, and the optimal separation distance should be determined based on a quantitative stability criterion. In this paper, we described a numerical approach for determining the optimal separation distance between multiple caverns for large-scale TES utilization. For reliable stability evaluation of multiple caverns, we employed a probabilistic method which can quantitatively take into account the uncertainty of input parameters by probability distributions, unlike conventional deterministic approaches. The present approach was applied to the design of a conceptual TES model to store hot water for district heating. The probabilistic stability results of this application demonstrated that the approach in our work can be effectively used as a decision-making tool to determine the optimal separation distance between multiple caverns. In addition, the probabilistic results were compared to those obtained through a deterministic analysis, and the comparison results suggested that care should taken in selecting the acceptable level of stability when using deterministic approaches.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.6 no.2
• /
• pp.166-176
• /
• 1996

The fundamental conditions for growing $CsLiB_{6}O_{10}$ crystal, new nonlinear optical material, were investigated. Stoichiometirc mixture of $CsLiB_{6}O_{10}$ composition resulted in the crystal of the same composition in the process of heating at the temperature above $600^{\circ}C$. No phase transition was observed in the $CsLiB_{6}O_{10}$ crystal in the temperature range of $600^{\circ}C~800^{\circ}C$, and $CsLiB_{6}O_{10}$ crystal melted congruently at $850^{\circ}C$. When the melt of this composition was cooled at rates of $1~150^{\circ}C/hr$, glass state ingot was formed regardless of cooling rates. However, $CsLiB_{6}O_{10}$ crystals were formed directly from the melt at any cooling rate in the presence of $CsLiB_{6}O_{10}$ seed crystal in the melt. Transparent $CsLiB_{6}O_{10}$ single crystal was grown from the melt using the seed crystal at the growing rate of 0.06 mm/hr in the furnace having the temperature gradient of $100^{\circ}C/cm$. Analysis of the single crystal showed that the crystal belonged to the noncentrosymmetric tetragonal space group 142d and unit cell dimensions were $a=10.467(1)\;{\AA},\;c=8.972(1)\;{\AA}\;and\;V=983.0(2)\;{\AA}^3$. Optical absorption edge of the crystal was observed at 180mm and the crystal showed a good optical transparency (70% transmittance, sample thickness 0.5 mm) in the wide wavelength range above 300 nm.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.2
• /
• pp.127-134
• /
• 2020

High supersonic aircraft are exposed to high temperature environments by aerodynamic heating during supersonic flight. Thermal protection system structures such as double-panel structures are used on the skin of the fuselage and wings to prevent the transfer of high heat into the interior of an aircraft. The thin-walled double-panel skin can be exposed to acoustic loads by supersonic aircraft's high power engine noise and jet flow noise, which can cause sonic fatigue damage. Therefore, it is necessary to examine the behavior of supersonic aircraft skin structure under thermal-acoustic load and to predict fatigue life. In this paper, we designed and fabricated thermal-acoustic test equipment to simulate thermal-acoustic load. Thermal-acoustic testing of the titanium specimen under thermal-acoustic load was performed. The analytical model was verified by comparing the thermal-acoustic test results with the finite element analysis results.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.36 no.6
• /
• pp.34-42
• /
• 2009

This study was executed to introduce a greenhouse style "Evergreen Park" to apartment complexes to target hands-on resident participation and application rather than a mere viewing of the plants as a way to provide convenient and profitable service to residents in a year-round center of usable outside space. The four key points can be summarized as follows: first, subtropical plants are evergreen broad-leaved trees, which maintain their green during all four seasons the leaves are thick and glossy. Greenhouses geared toward these subtropical trees-mainly broad-leaved evergreen species-are in planning to introduce these unique, elegant plants to temperate regions. Residentswill not only gain an education regarding these species but will be provided with the best quality evergreens at very reasonable maintenance costs. Second, subtropical plants greenhouses introduced in apartment complexes are suggested for structures connected via underground passage as well as free-standing structures so as to make use of geothermal heating and apply to reducing sunlighting. Third, as a way to provide (1) health & relaxation(evergreens, herb garden, water space), (2) community & education (plant flea market/plant hospital, plant-related lecture(exhibition), hands-on experience program), (3) a vine garden for year-round use such festivities as a Butterfly Festival, Aroma festival, Smile Oak Nuts, Candlelight Festival and Christmas Photo Site. Lastly, it has been suggested that the operation and maintenance of these greenhouses will be both by resident council operation management and by outsourcing company operation management.

• Journal of Society of Preventive Korean Medicine
• /
• v.10 no.1
• /
• pp.109-121
• /
• 2006

The purpose of this study was to determine factors influencing patient satisfaction with medical services in hospital, which is classified into environmental aspect, human services and procedural services. Based on the results of literature review, the study focused on effects of social-demographical factors on patient satisfaction. The environmental aspect of medical care services included medical equipment and facilities, hygiene, ventilation, heating and air-conditioning, waiting and resting space, ward space and parking facilities. Procedural service included registration process, bill payment, waiting time after registration, examination and prescription as well as appointment process. Human services consisted of physicians listening to stories of patients, examination duration, physicians' explanation and physicians' service. As for nurses, explanation about disease, examination procedure and results, kindness and nursing care were evaluated. Services provided by other staff members were also evaluated. Patient satisfaction, defined as individual attitude toward medical service as a whole, was measured using a questionnaire. A total of 700 in-or out-patients were surveyed in 6 hospitals with more than 300 beds in North Gyeongbuk Province. 1. The level of patient satisfaction varied with characteristics of patients. Male patients and those in their 30s had a low level of satisfaction. Dissatisfaction level was positively related to education level but negatively related to economic condition. 2. As for patient satisfaction with medical service providers and other employees in hospital, satisfaction level with physician's explanation about treatment was higher. But dissatisfaction levels with treatment duration and the lack of explanation about examination procedures were high, calling for improvement. Dissatisfaction level with nursing care was high, calling for training of nurses for better service. Given the low level of satisfaction with human services, hospital employees need to be trained to improve their service. 3. It Was found that administrative service was also a significant factor influencing patient satisfaction in addition to medical service. It is therefore important for hospitals to provide patients with prompt and convenient procedural service. 4. Environmental factors such as medical equipment and amenity facilities also affected patient satisfaction. Thus environmental condition, procedural service and human service are all important to improve medical service in hospital. In summary, procedural service was the most significant factor for patient satisfaction. The level of satisfaction in patients was also affected by human service and environmental condition. It is therefore necessary to take patient-oriented approach in providing medical service in an effort to improve patient satisfaction. The finding of a lower level of satisfaction with human service signifies the need for training of healthcare providers and other hospital employees for better services. The introduction of advanced management programs is also needed to improve procedures that patients go through in hospitals.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.6
• /
• pp.497-505
• /
• 2021

Due to recent underground space accidents, are a frequent occurence in Korea, the government established the basic plan for the construction of the IUGIM (Integrated Underground Geospatial Information Map) in 2015 as a measure for safety management of underground spaces. The development of IUGIM was partially completed as of 2021. The underground space management entity and related organizations are utilizing it. This study is being carried out as part of a plan to improve the usability of IUGIM, and to build a visualization system that compares real-time field data with stored data. A system, equipped with a visualization function for borehole data and 6 types of underground facilities built and managed on IUGIM; a tool capable of comparative analysis with real-time data measured in the field, is being built. The 6 types of underground facilities are water supply pipe, sewage pipe, power pipe, gas pipe, communication pipe, and heating pipe. The completed system was demonstrated at three locations in Seocho-gu, Gangnam-gu in Seoul. The field demonstration was carried out by accessing the mobile center and downloading IUGIM data, visualizing IUGIM data (surface creation, borehole information, underground facilities), and visualizing the GPR(Ground Penetrating Radar)-based data acquired at the field. As a result of the empirical results of IUGIM data and GPR-based field data, it was judged to be suitable. As a result of this study, it is judged that it can be helpful for safe construction at the excavation site.

• Journal of Astronomy and Space Sciences
• /
• v.12 no.2
• /
• pp.216-233
• /
• 1995

The distributions of the ionospheric conductivities, electric potential, ionospheric currents, field-aligned currents, Joule heating rate, and particle energy input rate by auroral electrons along with the characteristics of auroral particle spectrum are examined during moderately disturbed period by using the computer code developed by Kamide et al. (1981) and the ionospheric conductivity model developed by Ahn et al. (1995). Since the ground magnetic disturbance data are obtained from a single meridian chain of magnetometers (Alaska meridian chain) for an extended period of time (March 9 - April 27, 1978), they are expected to present the average picture of the electrodynamics over the entire polar ionosphere. A number of global features noted in this study are as follows: (1) The electric potential distribution is characterized by the so-called two cell convection pattern with the positive potential cell in the morning sector extending into the evening sector. (2) The auroral electrojet system is well developed during this time period with the signatures of DP-1 and DP-2 current systems being clearly discernable. It is also noted that the electric field seems to play a more important role than the ionospheric conductivity the conductivity over the poleward half of the westward electrojet in the morning sector while the conductivity enhancement seems to be more important over its equatorward half. (3) The global field-aligned current distribution pattern is quite comparable with the statistical result obtained by Iijima and Potemra (1976). However, the current density of Region 1 is much higher than that of Region 2 current at pointed out by pervious studies (e.g.; Kamide 1988). (4) The Joule heating occurs over a couple of island-like areas, one along the poleward side of the westward electrojet region in the afternoon sector. (5) The maximum average energy of precipitating electrons is found to be in the morning sector (07∼08 MLT) while the maximum energy flux is registered in the postmidnight sector (02 MLT). Thus auroral brightening and enhancement of ionospheric conductivity during disturbed period seem to be more closely associated with enhancement of particle flux rather than hardening of particle energy.