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An Analysis of Container Logistics System by Computer Simulation (시뮬레이션에 의한 컨테이너 물류시스템의 분석에 관하여(BCTOC를 중심으로))

  • 유승열;여기태;이철영
    • Journal of the Korean Institute of Navigation
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    • v.21 no.1
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    • pp.1-11
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    • 1997
  • Because of the sharp increase of its export and import container cargo volumes contrast to the lack of related Container Terminal facility, equipment and inefficient procedure, there is now heavy container cargo congestions in Pusan Container Terminal. As a result of such a situation, many container ships avoid their calls into Pusan port. This is a major cause that in tum kads to weakening intemational competitiveness of the Korean industry. This study, therefore, aims are to make a quantitative analysis of Container Terminal System through the computer simulation, especially focusing on its 4 sub-system of a handling system, 'it is checked whether the current operation is being performed effectively through the computer simulation. The overall findings are as folIows; Firstly, average tonnage of the ships visiting the BCTOC was 32,360 G/T in from January '96, to may '96. The average arrival interval and service time of container ships at BCTOC are 5.63 hours and 18.67 hours respectively. Ship's arrival and service pattern at BCTOC was exponential distribution with 95% confidence and Erlang-4 distribution with 99% confidence. Secondly, average waiting time and number of ships was 9.9 hours, 235 ships(38%) among 620 ships. Number of stevedoring container per ship was average 747.7 TED, standard deviation 379.1 TEU and normal distribution with 99% confidence. Thirdly, from the fact that the average storage days of containers at BCTOC are 2.75 days (3.0 days when import, 2.5 days when export). it is founds that most containers were transfered to the off-dock storage areas with the free periods(5 days when import, 4 days when export), the reason for which is considered to be the insufficient storage area at BCTOC. Fourthly, in the case of gate in-out at BCTOC, occupied containers and emptied containers are 89% and 11% respectively in the gate-in, 75% and 25% seperately in the gate-out. Finally, from the quantitative analysis results for container terminal at BCTOC, ship's average wating time of ships was found to be 20.77 hours and berth occupancy rate(${\rho}$) was 0.83. 5~6 berths were required in order that the berth occupancy rate(${\rho}$) may be maintained up to 60% degree.

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The Individual Heat-recovery ventilation system of Residential Buildings (주거용 건물의 개별 환기시스템 필요성에 관한 연구)

  • Shin, U-Cheul;Lee, Wang-Je;Yoon, Jong-Ho;Baek, Nam-Choon
    • KIEAE Journal
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    • v.14 no.6
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    • pp.99-104
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    • 2014
  • Recently supply of low energy house is increasing which can enhance energy efficiency and indoor environment comfort. Low energy house have to secure air tightness as well as thermal performance so house become high airtightness and inevitably need heat recovery ventilator to enhance indoor air quality. However, most of current ventilation systems are one-click, controlling the entire space so it causes increasing of heating load and fan power which makes it hard to save energy. Thus, Individual Control system is required which can achieve both enhancing indoor air quality and decreasing heating load and electric fan power. Thereby, in this study, we analyzed the correlation between ventilation and fan power through mock-up experiment and measured ventilation load under individual control system. As a result, under the condition of $24^{\circ}C$ of indoor temperature for 6 month(November to April) in Daejeon, ventilation load by fan speed was $10.9{\sim}19.6kWh/m^2{\cdot}a$ when operated 24 hours and $7.6{\sim}13.7kWh/m^2{\cdot}a$ when operated 12 hours in night time. In addition, it is possible to reduce at most 60% of ventilation load under the individual control system; measured ventilation load was $7.4kWh/m^2{\cdot}a$ when operated 24 hours, and $5.5kWh/m^2{\cdot}$ when operated 12 hours in night time.

Dynamic Simulation of a Hybrid Cooling System utilizing Heat Pump, Desiccant and Evaporative Cooler (열펌프, 데시칸트 및 증발식 냉각기를 조합한 하이브리드 냉방 시스템의 동특성 해석 연구)

  • Seo, Jung-Nam;Kim, Young-Il;Chung, Kwang-Seop
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.7 no.1
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    • pp.45-50
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    • 2011
  • Hybrid desiccant cooling system(HDCS) consists of desiccant rotor, regenerative evaporative cooler, heat pump and district heating hot water coil. In this study, TRNSYS and EES, dynamic and steady simulation programs were used for studying hybrid desiccant cooling system which is applied to an apartment house from June to August. The results show that power consumption of the hybrid desiccant cooling system is 70 kWh in June, 199 kWh in July and 241 kWh in August. Sensible and latent heats removed by the hybrid desiccant cooling system are 300 kWh, 301 kWh in June, 610 kWh, 858 kWh in July and 719 kWh, 1010 kWh in August. COP of the hybrid desiccant cooling system is 8.6 in June, 7.4 in July and 7.2 in August. COP of the hybrid desiccant cooling system decreases when latent heat load increases. Operation time of the system is 70 hours in June, 190 hours in July and 229 hours in August. Since the cooling load is largest in August, the operation time of August is longest for maintaining the indoor temperature at $26^{\circ}C$. Due to the characteristics of hybrid desiccant cooling system for efficiently handling both sensible and latent loads, this system can handle sensible and latent heat loads efficiently in summer.

A study on the establishment of an MES system that converges design, processing, and measurement during cutting (절삭가공 시 설계, 가공, 측정을 융합한 MES 시스템 구축에 관한 연구)

  • Park, Hae-Woong;Lee, Seung-Wook;Han, Heui-Bong;Yun, Jae-Woong;Choi, Kye-Kwang;Han, Seong-Ryeol;Kim, Kyung-A;Lee, Chun-Kyu
    • Design & Manufacturing
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    • v.15 no.2
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    • pp.42-48
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    • 2021
  • In this paper, when manufacturing large/multi-mold parts (more than 30 core parts),A mold manufacturing (tolerance) management system was established through design-processing linkage.The mold manufacturing (tolerance) management system is a design-based measurement shape/measurement position determination system, M/C processing-linked measurement drive system,It is composed of four parts: CAD-linked measurement result analysis system and manager mold part quality management system.In addition, the constructed system was applied to the field and the effect of system construction was evaluated by comparing it with the existing process.As a result of the evaluation, the measurement precision is within 0.02mm, and the time it takes to measure after the end of processing is shorter than that of the existing process.(12 hours → 2 hours) It was shortened to 16.7%.In addition, it was confirmed that the time required for reprocessing after measurement was reduced by 25% (4 hours → 1 hour) compared to the existing process.

On the Analysis of Transportation System in Mokpo Port (목포항 운송시스템의 분석에 관한 연구)

  • Nam, M.U.;Lee, C.Y.
    • Journal of Korean Port Research
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    • v.11 no.2
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    • pp.321-337
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    • 1997
  • Rapid change in the technological environment of marine transportation and the development of the ocean shipping industry have fostered a revolution in the port system. This in turn has caused major changes in the function and use of port in Korea. Aside from this. Mokpo Port, however continues to decline, because the existing port facilities and related subsystem are already obsolete with no chance of regaining operational effectiveness and treatment for proper implementation. Although a few studies have been done on the Mokpo Port, has not been found, any reseach for the analytical approach to the transportation system of it. This paper aims to make an extensive analysis of the physical distribution system in Mokpo Port focusing on the coordination of subsystems such as navigational aids system, quay handling and transfer system, storage system and inland transport system. The base of introduced simulation tool here is the queueing theory. The overall findings are as follows; 1. Among those vessels called at Mokpo Port in 1994, the average size of oceangoing vessels is 4,922.1 G/T, and the domestic is 317.8 G/T. The average arrival interval and service time of the domestic vessels are 6.0 hours and 24.1 hours respectively marking the berth occupation rate over 100%. Those for oceangoing vessels are 34.5 hours, 120.0 hours and 37.2%. In order to maintainin the berth occupation rate to 70% the capacity considering the 1994 of domestic piers must be extended to 145% and oceangoing vessels must be increased to 165% year called. 2. The capacity of approaching channel is enough to handle the total traffic volume. 3. Tugs are sufficiently being provided to handle all ships requiring their services 4. The capacity of storage and inland transportation systems are sufficient to handle the throughput and the yard stroage utilization rate of No.1 $\cdots$ No.5 is 4.5% and No.6 1S 30% of 1993's. 5. The utilization rate of LLc(Level Looping Crane) and PNT(PNeumaTic) are 2.7% and 18.8%, respectively. Practical solution and proposal for improvement of Transportation System in Mokpo Port are as follows; 1. To avoid the congestion in domestic pier introduction of a new port operation system is necessary allowing the domestic vessel to use the oceangoing pier. 2. To establish the port management information system to improve the efficiency of port operation. 3. To build a new storage system for high valued cargos including modernization of the present storage and handling system. 4. To insure the safety of navigation in approaching channel, The Vessel Traffic System including separation scheme is introduced. 5. To interest enormously on public relation to ship owner's association, shippers and consignees by showing that they can save cost and ship turnaround time in order to promote the call to Mokpo Port. At last, to be strategically change the function of Mokpo Port to the Leisure, Fishing & Ferry as well as Maritime port.

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Development of Portable Bio-signal Measurement System using Bluetooth for 24-hours Continuous Health Monitoring (24시간 건강상태 모니터링을 위한 Bluethooth를 사용한 소형 저전력 휴대형 Bio-signal 측정 장치를 개발)

  • 정현권;송길섭;나승유;이희영
    • Proceedings of the IEEK Conference
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    • 2001.06e
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    • pp.81-84
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    • 2001
  • This paper presents a potable bio-signal measurement system using Bluetooth for the 24-hours continuous health state monitoring of the elderly and the disabled. The measurement system has the functions of acquisition of various bio-signals, wireless data transmission and adjustment of parameters such as gain and cut-off frequency. This measurement system is designed according to the international specifications of the recommendation of AAMI (Association for the Advancement of Medical Instrumentation). The design targets of the developing system about volume and power consumption are 20x30x5mm$^3$ and 8mW.

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A Study on the Development of the Self test-system for the Marine Gyrocompass (선박용 자이로콤파스의 자기진단 시스템 개발에 관한 연구)

  • 이상집;임정빈
    • Journal of the Korean Institute of Navigation
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    • v.16 no.1
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    • pp.1-12
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    • 1992
  • In this study, the self test-system for the marine Gyrocompass was developed and the obtained results are summarized as follows : 1) Utilizing the newly developed self-test system, the time length for observing the transient state of Gyrocompass reading which has been over 4 hours can be reduced to less than 20 minutes. In addition, the dynamic characteristics of the Gyrocompass can be measured within 2 hours after starting the system. 2) Prior test and diagnosis was done by checking all parameters recurrently with period of 2.5minutes. 3) Testing and diagnosis results was shown in graphic mode and could be transmitted to INMARSAT unit using personal computer. 4) The results of the newly designed trouble algorithm for the system was found to be applicable under arbitrary given conditions.

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Studies on Absorption Ratio of Tobacco for Optimum Moisture Control (적정수분 관리를 위한 담배흡습속도에 관한 연구)

  • 정한주;김기환;민영근;김병구;양광규;오인혁
    • Journal of the Korean Society of Tobacco Science
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    • v.15 no.1
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    • pp.90-97
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    • 1993
  • 1. Average moisture content of tobacco in BIB silo was about 19: 1% until 4hours conditioned time, and then moisture variation of tobacco after 2hr conditioned was very small. 2. Application of mathematical model for ordering system. 1) The constant K in the exponential equation varies inversely with both relative humidity and equilibrium moisture. 2) Time needed to order blending tobacco leaves with standard moisture from bulking and blending silo was 4 hours. 3) Reconstituted tobacco sheet had higher moisture absorption ratio than Oriental and Burley tobacco. 4) For minimize of conditioning time in BIB silo, the values of K and Mo given in this study can be used in equation(1) to calculate moisture absorption ratio and optimum conditioning time. 3. Average moisture content and water activity of conditioned tobacco for 4 hours in BIB silo was about 20% and 0.65. In this condition. microbial life will inhibite 4. Physical properties of conditioned tobacco in bulking and blending silo for 4hours was virtually no change.

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Influences of Prolonged Extracorporeal Circulation on Organ Function in Dogs (장시간의 체외순환이 생체에 미치는 영향)

  • 김의윤
    • Journal of Chest Surgery
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    • v.7 no.1
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    • pp.73-78
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    • 1974
  • Influences on organ function were studied in animals during prolonged extracorporeal circulation with a bubble type of oxygenator. More than six hours of total cardiopulmonary bypass was performed under mild hypothermia by means of an extracorporeal circulation system in five dogs. Obtained results were summarized as follows. 1. The renal function was not so impaired seriously until four hours of extracorporeal circulation. However, there was more serious impairment of renal function in this study when extracorporeal circulation was carried out for a period of five hours or more. 2. There was gradual hepatic damage during extracorporeal circulation and the damage was more significant after bypass for a period of five to six hours. 3. There was a significant decrease in serum K during bypass, irrespective of the pump oxygenator prime with a high K solution. The reason for this is complex and due to many factors, however, it was evidently related to serum glucose levels during extracorporal circulation.

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Measurement of the Nursing Staff Needed for Two Specialized Nursing units in a University Hospital (간호업무량 측정 및 간호인력 수요산정)

  • 이윤신;박정호
    • Journal of Korean Academy of Nursing
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    • v.22 no.4
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    • pp.589-603
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    • 1992
  • This study investigated a process to estimate the need for nursing staff on the basis of a patient elassification system and the required care needs and activities. The investigation was carried out in the following four steps. Step 1. Patients were classified according to the amount of nursing care need on each shift as class I (mildly ill), class II (mederately ill), class III (acutely ill), and class IV (critically ill). Step 2. Measurement of the direct nursing care hours needed for each patient class, and measurement of indirect nursing care hourse and personal time of the nursing staff. Step 3. Calculation of he total nursing workload in a nursing unit. Step 4. Estimation of the nursing staff needed. The investigation was carried out from July 17th to 30th, during 24hours every other day. The subjects were the patients and the nursing staff on two units of Seoul National University Hospital, Korea. Some of the results from the investigation are as follows : 1) Distribution of patient classification On the neuro surgical (N.S.), the distribution was class I, 22 patient, 3, class II, 27 patients, class III, 26 patients, and class IV, 25 patients, For the orthopedic surgical unit(0.5.), it was class I, 43 patients, class II, 43 patients, class III, patients, and class IV, 3 patients. 2) Direct nursing care hours per day On the N.S. unit, 3.2 hours of direct nursing care were needed for class I, 3.9 hours for class II, 5.1 hours of class III, and 6.2 hours for class IV patients, while 2.0 hours for class I, 2.5 hours for class II, 3.5 hours for class III, 5.0 hours class IV patients were needed on the 0.5. units. 3) Analysis of direct nursing care activities Activities were classified into assessment and observation(47%), medication(38.7%), communiontion(5.1%), exercise(2.4%), elimination and irrigation(1.3%), treatmemt(1.1%), hygiene(0.8%), nutrition(0.8%), and hot and cold compress(0.1%). 4) Average hours of indirect nursing care per day. On the N.S. unit 4.2 hours, and on the O.S. unit, 3.5 hours of RN indirect care was needed. 5) The average personal time used by the of nursing staff was 17 minutes for both RNs and nursing assistants in the N.S. unit, and 32 minutes for both RNs and nursing assistants in the O.S. unit. 6) Estimation of nursing staff needed on two specialized units of a university hospital For the N.S. nursing unit of 43 beds, 31 nursing staff would be indicated. For the 0.5. nursing unit of the same number of beds, 19 nursing staff would be indicated.

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