• Journal of the Korean Society of Propulsion Engineers
• /
• v.14 no.5
• /
• pp.57-64
• /
• 2010

A performance test of inter propellant seal for a 75 ton class turbopump is conducted using water to evaluate leakage and endurance performance. Each part of fuel pump side and oxidizer pump side for a prototype inter propellant seal has been tested for verifying endurance performance during total accumulated test time 2,100 sec in water. The fuel pump side part with one-stage seal of carbon floating ring shows average leakage rate 13.7 gram/sec under average seal differential pressure 9.4 bar. On the other hand, the oxidizer pump side part with two-stage seal assembly of carbon floating rings shows average leakage rate 7.3 gram/sec under average seal differential pressure 9.5 bar. After the endurance performance test, the inter propellant seal shows good physical condition. A leakage performance test of the inter propellant seal for cryogenic environment will be performed using LN2 in the near future.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.1
• /
• pp.31-37
• /
• 2002

전자파 잔향실(Reverberating Shielded Enclosure)의 개념은 전자파 차폐실(Shielded Enclosure)에서 얻어진 측정결과를 개선하기 위하여 1968년도에 제안되었다. 이후 Reverberating 또는 Mode-Stirred Chamber는 EM Immunity 측정뿐만 아니라 EMI측정에서도 많이 적용되어 왔지만, 국제 표준 방식으로 적용되어 오지 못하다가 최근 EMI 복사 전력 측정 및 EM Immunity 측정시설로 유용하게 사용될 수 있다는 점이 부각되어 국제 표준 방식으로 적용하자는 분위기가 무르익어 이에 대한 활발한 논의가 계속되어 오고 있다. 이러한 전자파 잔향실을 이용하여 EMI 및 EMS 시험을 실시할 수 있는 방법을 규격화시키자는 제안이 '96년 프랑스 Mandelieu 국제 전자파 장해 특별위원회(CISPR:International Special Committee on Radio Interference)회의에서 검토된 후 '97년 일본 Yokosuka CISPR 회의에서 정식의제로 채택되었다. 이 안건에 대하여 대부분의 국가들이 제안 취지에 찬성하여 NWIP(New Work Item Proposal) 문서가 각국에서 회람되었다. 초기 전자파 잔향실은 전자파 장해 및 복사 내성 측정을 위한 대용시험 시설로서 1968년 미국 Mendes에 의해 전자파 차폐실 구조에 Stirrer를 이용하여 필드의 균일도를 확보할 수 있다는 전자파 잔향실 개념이 처음으로 제안되었다. 이후 이 분야의 연구는 미국 표준 기술 연구소(NIST: National Institute of Standard and Technology)등에서 연구가 활발히 진행되고 있으며, 국제 표준화 기구인 CISPR에서 전자파 장해 및 내성 시험을 위한 대용시험 시설로서 활용하기 위하여 규격 작업이 진행중에 있다. 또한 최근 전자파 장해 방지를 위한 규제 주파수가 1∼18㎓ 까지 확장됨에 따라 이 주파수 대역에서 시험장으로 활용할 수 있는 전자파 잔향실이 새롭게 부각되고 있다. 전자파 잔향실은 기본적으로 공진 모드를 활용하기 때문에 일정한 크기의 잔향실 내부에서 전자파 균일성을 확보할 수 있는 모드 수에 의해 하한 주파수가 결정되며 충분한 모드 분포상태에서 Stirrer를 사용하여 필드 경계를 이동시킴으로서 확률적으로 균일한 필드분포를 확보하게 된다. 주파수가 증가함에 따라 모드수는 증가하기 때문에 하한 주파수 이상의 대역에 대한 시험시설로 활용할 수 있으며, 특히 ㎓ 대역에서 사용하기에 적합한 대용시험시설이라고 볼 수 있다.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.10 no.3
• /
• pp.173-180
• /
• 2007

Oscillating wave amplitude in a bottom-mounted OWC chamber designed for wave energy converter is investigated by applying characteristic wave conditions in Korean coastal water. The effects of shape parameters of OWC chamber in a view of wave energy absorbing capability are analyzed. Both experimental and numerical approaches are adopted and their results are compared to optimize the shape parameters which can result in a maximum power production under given wave distribution. The experiment was carried out in a wave flume under 2-D assumption of OWC chamber. The numerical scheme employed a hybrid Green integral equation which adopts the Rankine Green function inside chamber to take account of fluctuating air pressure, while it uses the Kelvin Green function in outer domain. Air duct diameter, chamber width, and submerged depths of front skirt and back wall of chamber changes the magnitude and peak frequency of wave absorption significantly.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.05a
• /
• pp.47-53
• /
• 2010

A performance test of a 75 ton class turbopump inter propellant seal is conducted using water to evaluate leakage and endurance performance. Each fuel pump side part and oxidizer pump side part of a prototype inter propellant seal has been tested for verifying endurance performance during total accumulated test time 2,100 sec in water. The fuel pump side part with 1 stage carbon floating ring seal shows average leakage rate 13.7 gram/sec under average seal differential pressure 9.4 bar. On the other hand, the LOx pump side part with 2 stage carbon floating ring seal shows average leakage rate 7.3 gram/sec under average seal differential pressure 9.5 bar. After the endurance performance test, the inter propellant seal shows good physical condition. A cryogenic leakage performance test of the inter propellant seal will be performed using LN2 in the near future.

• Journal of Korean Home Economics Education Association
• /
• v.24 no.2
• /
• pp.1-15
• /
• 2012

This study investigated the causes of the dislikes of Practical Arts education of elementary school students. This study was to provide the foundation for the proposition of alternative plans to make more students participate pleasantly and actively in Practical Arts classes. Data were collected via an open-ended survey from 273 elementary school students and through telephone interviews with five elementary school teachers. The data were analyzed inductively by NVivo. After the analysis of the student data, the analysis of the teacher data was conducted according to the variables from the student data. The results of this research were as follows: First, with regard to the causes of the students' dislikes of Practical Arts classes, extrinsic factors such as instruction management, instruction content, teaching facilities and equipment, and teacher characteristics were elicited. Intrinsic factors included complaints about failing to meet students' expectation from Practical Arts, negative perception of Practical Arts, the interest, competency, and fear of the students. Secondly, the students who learned Practical Arts from the Practical Arts specialty teachers gave more answers on instruction management, instruction content, and teacher characteristics than the students who learned Practical Arts from their homeroom teachers did. The students who learned Practical Arts from their homeroom teachers answered that they disliked Practical Arts because of lack of lab facilities and practice than their counterparts did. The analyses of teacher data provided the reasons and contexts of the dislikes of the students such as teaching facilities and equipment, and the anxiety of the students.

• The Journal of Internal Korean Medicine
• /
• v.39 no.6
• /
• pp.1306-1312
• /
• 2018

Objectives: This study presented the case of a 49-year-old Korean female with phantom limb pain after below right knee amputation and aimed to assess the effectiveness of Korean medicine treatment. Methods: The patient was treated with scalp acupuncture, electroacupuncture and herbal medicine. We executed a numerical rating scale (NRS), conducted a global assessment (G/A), administrated a Short-Form McGill Pain Questionnaire 2 (SF-MPQ-2) and measured total daily sleep time to evaluate symptom improvement. Results: The patient's G/A scores decreased from 10 to 2 and SF-MPQ-2 points decreased from 20 to 6 after treatment. The total daily sleep time did not changed due to anxiety. Conclusions: This study suggests that Korean medicine treatment could be effective in treating phantom limb pain after amputation. Further studies are needed.

• The Journal of Internal Korean Medicine
• /
• v.40 no.4
• /
• pp.709-722
• /
• 2019

Objective: The purpose of this study was to report the effect of traditional Korean medicine (TKM) in alleviating the side effects of lung cancer patient undergoing immunotherapy. Method: A 43-year-old man, who was diagnosed with non-small cell lung cancer, received pembrolizumab treatments. The patient was treated with acupuncture and herbal medicine (Geoeoyangpye-tang) to control various uncomfortable symptoms. The degree of pain was measured by the numeric rating scale (NRS). The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Core 30 (EORTC QLQ-C30) and the EORTC 13-item lung cancer-specific module (EORTC LC-13 questionnaire) were used to assess the change in the quality of life. Results: After the TKM treatment, the flank pain and arthralgia based on the NRS were significantly improved. Various uncomfortable symptoms such as fatigue, dyspnea, insomnia, and loss of appetite were also significantly improved, based on the EORTC QLQ-C30 and EORTC QLQ-LC13. The size of the primary tumor was decreased during treatment. The disease status was stable radiologically after two months from discharge.

• The Journal of the Society of Stroke on Korean Medicine
• /
• v.18 no.1
• /
• pp.87-96
• /
• 2017

■ Objectives The purpose of this clinical study is to evaluate the effect of Korean Medical Treatment on a 79 years old Korean female with shoulder pain after stroke. ■ Methods She was treated with moxibustion, acupuncture, electroacupuncture and herbal medicine. We evaluated the improvement by Numeric Rating Scale(NRS) of shoulder pain and frequency of awakening due to shoulder pain ■ Results After 24 Days, total score of NRS was decreased from 7 to 2.1. Average sleep time was increased and waking up due to shoulder pain was decreased during the night. ■ Conclusions This study suggests that Korean medical treatment, especially Moxibustion could be effective to reduce shoulder pain and alleviate sleep disturbance. Further studies are needed.

• The Journal of the Society of Stroke on Korean Medicine
• /
• v.16 no.1
• /
• pp.25-34
• /
• 2015

■ Objectives The purpose of this case report is to show the effect of korean medicine on a progressive supranuclear palsy patient with gait disturbance and dizziness. ■ Methods A patient with gait disturbance and dizziness diagnosed as progressive supranuclear palsy was treated with herbal medicine, acupuncture, electro-acupuncture, moxibustion. The period of admission is 16 days and we evauated the improvements of symptoms by the Unified Parkinson's Disease Rating Scale(UPDRS), Numeric Rating Scale(NRS) and Global Assessment(G/A). ■ Results After taking Modified Bosimhwan andbeing treated by acupuncture therapy, improvements of gait disturbance and dizziness are observed. ■ Conclusion This case report proved the effect of Korean medicine on progressive supranuclear palsy.

• Defense and Technology
• /
• no.10 s.164
• /
• pp.48-51
• /
• 1992

항공기 비행품질에 영향을 주는 설계분야는 크게 3가지로 항공기 형상, 조종체계 및 조종실 배치로 분류됩니다. 이들 3가지 설계분야 중에서 조정실의 운용자 인간공학적인 요구 사항을 고려하지 않으면 항공기 운용성 품질중에 3분의 1이 감소될수 있습니다 항공기를 개발할때에 개발자는 그 항공기를 운용하는 운용자의 인체, 생리, 심리, 습관 등을 고려해, 항공기 조종실의 인간공학적 최적화 설계 및 배치를 개발초기단계부터 적용해야 합니다. 항공기의 조종실의 인간공학적 최적화 설계 및 배치를 개발초기단계부터 적용해야 합니다. 항공기의 조종실 품질은 조종사가 항공기 비행 임무를 수행할 때에 항공기 비행을 위한 용이한 정보 인식, 용이한 정보 결심 및 용이한 조종의 특성을 조종사에게 제공할 때 항공기 비행 품질이 좋아질 것입니다