• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.7-24
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• 1977

This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.962-973
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• 2017

Concerns about an air pollution are gradually increasing at home and abroad. The automotive and fuel researchers are trying to reduce emissions and greenhouse gases of vehicles through a research on new engine designs and innovative after-treatment systems using clean fuels (eco-alternative fuel) and fuel quality improvements. In this paper, we stduy the emission characteristics of greenhouse gases on seven vehicles using gasoline, diesel, and LPG by legal test mode in domestic and abroad.(Urban mode, Highway mode, rapidly acceleration and deceleration, using air conditioner, low temperature condition) Regardless of fuels, most of the greenhouse gases tend to show the worst results in cold FTP-75 mode. In the case of A vehicles (2.0 MPI) and B vehicles (2.4 GDI) using a gasoline fuel, the factors that increase greenhouse gases are in order of a rapidly acceleration and deceleration, using air conditioner, low temperature condition. But G vehicles(LPLi) have different emission characteristics from another vehicles. In the case of A vehicles (2.0 w/o DPF) and B vehicles (2.2 with DPF) using a diesel fuel, the factors that increase greenhouse gases are in order of a rapidly acceleration and deceleration, using air conditioner, low temperature condition. However, the factor of F vehicles are in order of low temperature condition, using air conditioner, rapidly acceleration and deceleration. In conclusion, it will be an effective method to apply different technologies of emission reduction for each fuel.

• Journal of the Daesoon Academy of Sciences
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• v.24_2
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• pp.85-115
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• 2015

The Reordering of the Universe(天地公事) pursuing the Latter world(後天)'s ideal world while denying the Former world(先天) is composed of enormous rituals. The Dosu(度數) is formed through these rituals and the world is transformed according to the Dosu. The people who follow the Sangje(上帝), the subject of this universe reordering and also participate in the Reordering of the Universe are called as the followers. The follower group can be said as a ritual group in the aspect that they participate in the ritual for the Reordering of the Universe. They not only observed the rituals but also actively participated in them, so took certain roles in forming the Dosu. That is, they performed certain, given roles in developing the rituals, or actively proposed their ideas under the Sangje's leadership, and participated in the process realizing the Dosu. Therefore it can be said that they were a group initiatively participating in the process overcoming the Former world's Sangguk(相克) world, and making the latter world's ideal world. It seemed that the followers at that time might have gone through a certain entrance ritual process in order to join in such a follower group. The 『Jeon-Gyeong』 recorded the entrance rituals of a man called as Cha Gyeong Seok among tremendous followers relatively in detail. According to the 『Jeon-Gyeong』, he first had to get a unique test in the entrance process, and the test was proceeded in several stages: the wisdom test reflecting the Sangje's unusual intelligence, the patience test to endure physical, psychological pains for the great ethic, and the test to evaluate the testee's ability to give up past oneself and to follow the Sangje with a new body & mind. In the process separating himself from the past his appearance, Gyeong-Seok, the candidate to enter, faced a liminal situation, and then performed the incorporation rite. In this process, the purification rite going him out of the past relationship of benefits & grudges was performed, and he was given the regulations to comply as a member of the follower group. Through such serial processes, his entrance in the follower group was allowed. What requested to the candidate in this entrance process was the severance from one's past. For that, the candidate was needed to go out of his past life habits, to free from the relationship of benefits and grudges, and to sever him from his past faults. Such severance was the precondition for him to go out of the Former world's negative reality and to break from the Sanggeuk habits. Another thing requesting to the candidate as well as the severance from his past was to establish a new ideal. The new ideal should be matched with the ideal of the Reordering of the Universe whose main ideology was the Haewon-Sangsaeng(解冤相生). Such ideal can be said as the driving force to proceed toward the new ideal world of Latter World. And the candidate was requested to purify his mind and to participate in the Universe Fair Judgement (天地公庭). That can be said as an important condition for the new member directly to participate in the ritual of the Reordering of the Universe dramatically transforming the world. Finally, the candidate was given the regulations for his ascetic practice(修道) as well as his participation in the Reordering, and was requested to comply them. After becoming a member of this follower group, one had to practice his asceticism through the compliance with such regulations and the training of mantras(呪文) in order to accomplish the goal called as Dotong(道通). By fulfilling these requirements, the newly entered member could have the qualification to perform a certain role in the ritual of the Reordering of the Universe, and could accomplish his religious ideal.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.517-528
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• 2007

Domestic or international existing researches regarding rail damage factors are focused on laying, vehicle conditions, driving speed and driving habits and overlook characteristics of track structure (elasticity, maintenance etc). Also in ballast track, as there is no special lateral spring stiffness of track also called as ballast lateral resistance in concrete track, generally, existing study shows concrete track has 2 time shorter life cycle for rail replacement than ballast track due to abrasion. As a result of domestic concrete track design and operation performance review, concrete track elasticity is lower than track elasticity of ballast track resulting higher damage on rail and tracks. Generally, concrete track has advantage in track elasticity adjustment than ballast track and in case of Europe, in concrete track design, it is recommended to have same or higher performance range of vertical elastic stiffness of ballast track but domestically or internationally review on lateral spring stiffness of track is very minimal. Therefore, through analysis of service line track on site measurement and analysis on performance of maintenance, in this research, dynamic characteristic behaviors of commonly used ballast and concrete track are studied to infer elasticity of service line track and experimentally prove effects of track lateral spring stiffness that influence curved rail damage as well as correlation between track elasticity by track system and rail damage to propose importance of appropriate elastic stiffness level for concrete and ballast track.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.172-191
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• 2023

This study was undertaken to strategize the mixed traffic operation of autonomous vehicles in the pilot zone. This was achieved by analyzing the changes expected when autonomous vehicles are mixed in the autonomous vehicle pilot zone. Although finding a safe and efficient traffic operation strategy is required for the pilot zone to serve as a test bed for autonomous vehicles, there is no available operation strategy based on the mixture of autonomous vehicles. In order to presents a traffic operation strategies for each period of autonomous vehicle introduction, traffic efficiency and safety analysis was performed according to the autonomous vehicle market percentage rate. Based on the analysis results, the introduction stage was divided into introductory stage, transition period, and stable period based on the autonomous vehicle market share of 30% and 70%. This study presents the following traffic operation strategies. Considering the traffic flow operation strategy, we suggest the advancement of the existing road infrastructure at the introductory stage, and operating an autonomous driving lane and the mileage system during the transition period. We also propose expanding the operation of autonomous driving lanes and easing the speed limit during the stable period. In the traffic safety strategy, we present a manual and legal system for responding to autonomous vehicle accidents in the introductory stage, an analysis of the causes of autonomous vehicle accidents and the implementation of preventive policies in the transition period, and the advancement of the autonomous system and the reinforcement of the security system during the stable period. Through the traffic operation strategy presented in this study, we foresee the possibility of preemptively responding to the changes of traffic flow and traffic safety expected due to the mixture of autonomous vehicles in the autonomous vehicle pilot zone in the future.

• Journal of Korean Academy of Nursing Administration
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• v.4 no.2
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• pp.307-319
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• 1998

This study is an empirical investigation and study on the measurement of nursing service quality as perceived by patients. A series of H1. H2. H3 alternative hypotheses were tested using a sample of 250 patients in Taegu City. Korea. HI hypothese were tested for application of five component of service quality (SERVQlTAL and SE RPERF : tangiblity. reliability. responsiveness. accessibility. understandability) in Taegu area Hospitals. Validity test - the five components of service quality were rearranged into two components of service quality (personal factor. nonpersonal factor). Although SERVQUAL was verified in USA. application for five components of service quality in Korea indicated that it need more analytical studies. Nobody can deny the fact that the recent growth of the nursing service quality is one of the most important driving forces of hospital management. In many hospitals. the nursing quality charges more than 50% of the medical service quality. As a result. many hospital managers should be enormous interests in the investment potentiality of the nursing service. However. doesn't many researchers invest their time and effort on the research of the quality control in nursing service. Nursing service management is the process to satisfy customer's desires and expectations through the various service activities. Presently nursing service are being faced with three Common tasks of improving quality of nursing service. competitively differential advantage and productivity because of quantitative expansion of Nursing service. Such a phenomenon is also found in our medical service industry. resulting from increasing demands for medical service owing to national medical insurance policy and consumer's attitude change emphasizing prevention of illness. excessiveness of medical facilities in large cities and increasing medical lawsuits due to influence of consumerism. Therefore. under such circumstances. this research on nursing service is conducted from nursing managements to improve the nursing service quality problems faced by medical institutions. The results of this theoretical/empirical research are as follows: 1. Nursing service Quality is regarded as patients' perceived quality and evaluated on the basis (5 dimension) of technical and functional quality. 2. Nursing service Quality is a concept of patients evaluation on the measurable multi-dimensions intrinsic and extrinsic attributes of service. 3. Nursing service Quality is conceptually defined as the difference between the perceived service and the expected service. 4. Korean consumers trend to evaluate nursing service quality based on such dimensions as responsiveness and reliability. understandability. accessibility. tangibility. 5. After analyzing whether or not there are some differences in respective medical institution. it was found that there are significant difference on understandability. reliability. communicability. courtesy. competence. 6. After analyzing the difference between the expected nursing service and the nursing perceived service, it was found that the expected nursing service is higher than the perceived service in every medical institution. 7. HI hypothesis was tested with regard to the validity test between SERVQUAL and SERVPERF in nursing service quality. The result of validity test between SERVQUAL and SERVPERF was found to have differential result. That is the R2 of SERVPERF is higher than that of SERVQUAL. Therefore. HI was verified in nursing management. H2. H3 hypotheses were tested whether or not the nursing service quality and patient satisfaction is the preceding variable. The result of H2 hypothes is that the nursing service quality is the preceding variable of patient satisfaction and the patient satisfaction is that of revisiting intention. After analyzing whether or not there is any differences on the demographic variable of five nursing service quality factor. it was found that there are statistically significant differences on communicability and courtesy at the sex. understand ability. accessibility and tangibility at the age. understandability at the academic background respectively.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.133-144
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• 2004

A model and a measure which can evaluate the risk of rear end collision are developed. Most traffic accidents involve multiple causes such as the human factor, the vehicle factor, and the highway element at any given time. Thus, these factors should be considered in analyzing the risk of an accident and in developing safety models. Although most risky situations and accidents on the roads result from the poor response of a driver to various stimuli, many researchers have modeled the risk or accident by analyzing only the stimuli without considering the response of a driver. Hence, the reliabilities of those models turned out to be low. Thus in developing the model behaviors of a driver, such as reaction time and deceleration rate, are considered. In the past, most studies tried to analyze the relationships between a risk and an accident directly but they, due to the difficulty of finding out the directional relationships between these factors, developed a model by considering these factors, developed a model by considering indirect factors such as volume, speed, etc. However, if the relationships between risk and accidents are looked into in detail, it can be seen that they are linked by the behaviors of a driver, and depending on drivers the risk as it is on the road-vehicle system may be ignored or call drivers' attention. Therefore, an accident depends on how a driver handles risk, so that the more related risk to and accident occurrence is not the risk itself but the risk responded by a driver. Thus, in this study, the behaviors of a driver are considered in the model and to reflect these behaviors three concepts related to accidents are introduced. And safe stopping distance and accident occurrence probability were used for better understanding and for more reliable modeling of the risk. The index which can represent the risk is also developed based on measures used in evaluating noise level, and for the risk comparison between various situations, the equivalent risk level, considering the intensity and duration time, is developed by means of the weighted average. Validation is performed with field surveys on the expressway of Seoul, and the test vehicle was made to collect the traffic flow data, such as deceleration rate, speed and spacing. Based on this data, the risk by section, lane and traffic flow conditions are evaluated and compared with the accident data and traffic conditions. The evaluated risk level corresponds closely to the patterns of actual traffic conditions and counts of accident. The model and the method developed in this study can be applied to various fields, such as safety test of traffic flow, establishment of operation & management strategy for reliable traffic flow, and the safety test for the control algorithm in the advanced safety vehicles and many others.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.257-267
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• 2023

Purpose. The purpose of the study was to fabricate a prototype robotic simulator for dental education, to test whether it could simulate mandibular movements, and to assess the possibility of the stimulator responding to stimuli during dental practice. Materials and methods. A virtual simulator model was developed based on segmentation of the hard tissues using cone-beam computed tomography (CBCT) data. The simulator frame was 3D printed using polylactic acid (PLA) material, and dentiforms and silicone face skin were also inserted. Servo actuators were used to control the movements of the simulator, and the simulator's response to dental stimuli was created by pressure and water level sensors. A water level test was performed to determine the specific threshold of the water level sensor. The mandibular movements and mandibular range of motion of the simulator were tested through computer simulation and the actual model. Results. The prototype robotic simulator consisted of an operational unit, an upper body with an electric device, a head with a temporomandibular joint (TMJ) and dentiforms. The TMJ of the simulator was capable of driving two degrees of freedom, implementing rotational and translational movements. In the water level test, the specific threshold of the water level sensor was 10.35 ml. The mandibular range of motion of the simulator was 50 mm in both computer simulation and the actual model. Conclusion. Although further advancements are still required to improve its efficiency and stability, the upper-body prototype simulator has the potential to be useful in dental practice education.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.120-129
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• 2023

To evaluate the vertical loads on railway bridges, conventional load tests are typically conducted. However, these tests often entail significant costs and procedural challenges. Railway conditions involve nearly identical load profiles due to standardized rail systems, which may appear straightforward in terms of load conditions. Nevertheless, this study aims to validate load tests conducted under operational train conditions by comparing the results with those obtained from conventional load tests. Additionally, static and dynamic structural behaviors are extracted from the measurement data for evaluation. To ensure the reliability of load testing, this research demonstrates feasibility through comparisons of existing measurement data with sensor attachment locations, train speeds, responses between different rail lines, tendency analysis, selection of impact coefficients, and analysis of natural frequencies. This study applies to the Dongho Railway Bridge and verifies the applicability of the proposed method. Ten operational trains and 44 sensors were deployed on the bridge to measure deformations and deflections during load test intervals, which were then compared with theoretical values. The analysis results indicate good symmetry and overlap of loads, as well as a favorable comparison between static and dynamic load test results. The maximum measured impact coefficient (0.092) was found to be lower than the theoretical impact coefficient (0.327), and the impact influence from live loads was deemed acceptable. The measured natural frequencies approximated the theoretical values, with an average of 2.393Hz compared to the calculated value of 2.415Hz. Based on these results, this paper demonstrates that for evaluating vertical loads, it is possible to measure deformations and deflections of truss railway bridges through load tests under operational train conditions without traffic control, enabling the calculation of response factors for stress adjustments.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.4
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• pp.327-338
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• 2014

The objective of this study is to enhance the effectiveness of Korean Inspection and Maintenance (I/M) program. Three main tasks are: to measure pollutant emissions of in-use light-duty diesel vehicles (LDVs); to evaluate the validity of existing smoke control scheme for low-smoke-emitting vehicles, which have diesel particulate filters, DPF, to meet stringent Euro-5 emission limits; and to assess the necessity and the benefit of $NO_x$ inspection, which is not involved in current I/M program. We measured second-by-second smoke, particulate and gaseous emissions of 27 LDVs using opacity smoke meter, photo-acoustic soot sensor, and portable emissions measurement system, respectively, under the Korean I/M test driving cycle, KD-147. We find that the DPF plays a key role in controlling soot, which can be considered as black carbon contained in particulate matter. Thus, from an I/M perspective, we believe smoke inspection strategies for Euro-5 diesel vehicles should be more focused on the capability of detecting DPF malfunctions or failures, in order to keep DPF properly functional. Fleet averaged distance-specific $NO_x$ emissions are consistently higher than corresponding emission limits, and the values are similar among pre-Euro-3, Euro-3, and Euro-4 vehicle fleets. These findings indicate that the $NO_x$ inspection should be incorporated into current I/M program in order to manage urban $NO_x$ emissions. This research allows the Korean I/M program keep pace with developments in vehicle technologies, as well as the increased emphasis on $NO_x$ with respect to air quality and human health.