• 품질경영학회지
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• 제40권3호
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• pp.245-258
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• 2012

Purpose: Recently, many quality issues are aroused in military forces, such as failures in K-series weapons, combat boots defects and 40mm ammunition explosion accident. To address these problems, the one and only government defense quality assurance agency, DTaQ(Defense Agency for Technology & Quality) tried to improve many quality assurance procedures and introduced new systems such as MRA(Manufacturing Readiness Assessment), TRA(Technology Readiness Assessment), and etc. However, as the amount of war supplies increasing every year, the resource(budget and manpower) for quality assurance is limited. Therefore, DTaQ had difficulty to handle the issue efficiently and effectively, and we propose the method to address this problem. Methods: The most popular quality assurance technique is a sampling method, in this research, we first review the many sampling techniques and compare the strength and weakness of each method. After then, we selected the most appropriate sampling techniques and applied the procedures in combat force support material and ammunition areas. Results: We can reduce the number of samples dramatically, thus the required amount of labor time and money can be saved. Also, the new sampling technique enforces the supplier to produce the product which meets the target value(desirable value). Conclusion: We can reduce the number of samples dramatically, thus the required amount of labor time and money can be saved. Also, the new sampling technique enforces the supplier to produce the product which meets the target value(desirable value). Lastly, since the new sampling method requires many numerical calculations, we developed a simple android OS smart-phone application which can be used easily in field.

• 터널과지하공간
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• 제17권5호
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• pp.372-380
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• 2007

침하로 인한 지표 손상대는 지하 채굴로 인해 발생되는 결과로서, 오랜 기간 동안 서서히 또는 급작스럽게 발생할 수 있다. 이러한 지표 손상대는 싱크홀 혹은 트러프형 침하에서 대규모 슬라딩에 이르기까지 다양한 형태로 관찰된다. 침하 발행 위험에 대한 평가는 광산 침하의 영향을 받는 지역에 있어서는 매우 중요하다. 이러한 위험도 평가나 침하 예측을 위해 경험적 모델, 프로파일함수, 영향 함수 그리고 수치해석과 같은 다양한 방법들이 적용되어 왔다. 본 연구에서는 다양한 인자들 중 지배적으로 침하 현상을 유발할 수 있는 채굴적과 관련한 정보, 즉 채굴적의 위치 및 규모의 정보를 확산이론과 연계한 비교적 간단한 침하 위험도 평가 기법을 제안하였다. 확산 모델은 지반 침하 기구를 설명할 수 있는 입자 모델과 상사관계를 가진다. 확산 모델을 폐금속광 및 폐석탄광 지역의 침하 위험도 작성에 적용하였다. 침하 위험도 평가를 위한 확산 모델은 매우 간단하지만 효율적인 방법임을 확인할 수 있었다.

• 터널과지하공간
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• 제27권2호
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• pp.109-119
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• 2017

다양한 현장조건을 고려하기 위하여 필라 폭, 암반등급, 측압계수를 달리한 각종 병설터널을 모델링하고, 수치해석과 모형실험을 통해 필라의 안정성을 알아보았다. 수치해석을 통해 얻어진 필라 중앙부의 응력, 필라 전체의 평균응력, 필라 좌우단부의 응력을 각각 적용하여 필라의 강도/응력비를 구하였다. 이중 필라 좌우단부의 응력을 적용하였을 때의 강도/응력비는 가장 보수적인 값을 나타내었고, 분할굴착과 지보체계를 고려한 시공단계해석에서도 굴착 시점과 부합한 실제적인 값을 보였다. 또한, 병설터널의 모형실험에서 필라의 파괴균열은 필라 좌우단부로부터 필라 중앙부를 향해 점진적으로 발생하였다. 따라서 필라의 국부적 손상을 방지하고 터널 안정성을 보수적으로 평가하기 위해서는 필라 좌우단부의 응력을 적용하여 필라의 강도/응력비를 구하는 방법이 적합한 것으로 판단된다.

• 한국도로학회논문집
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• 제19권1호
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• pp.63-72
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• 2017

PURPOSES : The purpose of this study is to investigate the fundamental behaviors such as stresses and deflections of the middle slab in a double-deck tunnel for the development of a middle slab design guide. METHODS : The middle slab has been divided into the following three different sections as according to its structural differences: the normal section, expansion joint section, and emergency passageway section. The normal section of middle slab represents the slab supported by brackets installed continuously along the longitudinal direction of tunnel lining. The expansion joint section refers to a discontinuity of middle slab due to the existence of a transverse expansion joint. The emergency passageway section has an empty rectangular space in the middle slab that acts as an exit in an emergency. The finite element analysis models of these three sections of middle slab have been developed to analyze their respective behaviors. RESULTS : The stresses and deflections of middle slab at the three different sections decrease as the slab thickness increases. The emergency passageway section yields the largest stresses and deflections, with the normal section yielding the smallest. CONCLUSIONS : The stress concentrations at the corners of the passageway rectangular space can be reduced by creating hunch areas at the corners. The stresses and deflections in the emergency passageway section can be significantly decreased by attaching beams under the middle slab in the passageway area.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.667-671
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• 2012

Low frequency noises (up to about 200 Hz) mainly occur due to particular modes, resulting in booming noises, and in general the solutions may be found based on mode controls where conventional methods such as FEM can be used. However, at higher frequencies between 0.3~ 1 kHz, as the number of modes rapidly increase, radiation characteristics from structures, performances of damping sheets and sound packages may be more crucial rather than particular modes, and consequently the conventional FEM may be less practical in dealing with this kinds of structure-borne problems. In this context, so-called 'mid-frequency simulation model' based on FE-SEA hybrid method is studied and validated. Energy Transmission loss (i.e. air borne noise) is also studied. A dash panel component is chosen for this study, which is an important path that transfers both structure-borne and air borne energies into the cavity. Design modifications including structural modifications, attachment of damping sheets and application of different sound packages are taken into account and the corresponding noise characteristics are experimentally identified. It is found that the dash member behaves as a noise path. The damping sheet or sound packages have similar influences on both sound radiation and transmission loss. The comparison between experiments and simulations shows that this model could be used to predict the tendency of noise improvement.

• 대한한방내과학회지
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• 제40권6호
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• pp.1051-1062
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• 2019

Objectives: Chest pain presents diagnostic and therapeutic challenges because of its various etiologies. Many patients have chest pain from unknown causes and persistent chest pain in spite of standard treatment. The purpose of this study was to investigate the effectiveness of a Korean herbal medicine called Pyungjinsujeom-san (PSS) in relieving chest pain. Methods: We reviewed the electronic medical records of patients who visited the Korean Medical Clinic of Cardiology at Kyunghee University Hospital at Gangdong from January 2009 to July 2019, with the chief complaint of chest pain and who were treated with PSS. The mean severity of chest pain measured on the Numerical Rating Scale was compared before and after the administration of PSS. Results: The mean severity of chest pain of 20 patients decreased significantly from 6.80±1.61 to 1.35±0.9 after taking PSS (p<0.001). Most patients had symptoms of phlegm and food retention, including indigestion, postprandial fullness, and epigastric pain.Conclusions: These results suggest that PSS may be effective in relieving chest pain from various causes, particularly in patients with symptoms of phlegm and food retention.

• 대한한방내과학회지
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• 제40권6호
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• pp.1268-1277
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• 2019

Objective: The purpose of this study was to report the effectiveness of Korean medicine in the treatment of functional dyspepsia in a fibromyalgia patient with a history of long-term NSAIDs use. Methods: The patient was diagnosed as a Soeumin, one of the four constitution types in Korean medicine, and treated with herbal medicines such as Seungyangikgibuja-tang and Pyeongjinsunjeom-san. Acupuncture and moxibustion treatment were also performed. The severity of symptoms was assessed using the Numerical Rating Scale (NRS) of epigastric pain, daily oral intake changes, the Korean Gastrointestinal Symptom Rating Scale (KGSRS), the Gastrointestinal Symptom Score (GIS), and the Functional Dyspepsia-Quality of Life (FD-QOL) score. Results: After treatment for 48 days, the severity of epigastric pain decreased from NRS 8 to NRS 0, and daily oral intake was increased. The KGSRS score decreased from 55 to 43, the GIS score was reduced from 18 to 10, and the FD-QOL score also decreased from 69 to 55. Conclusions: This study suggests that Korean medical treatment could be an effective option for treating functional dyspepsia in fibromyalgia patients with a history of long-term NSAIDs use.

• 대한물리의학회지
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• 제13권1호
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• pp.49-62
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• 2018

PURPOSE: This study investigated the influence of a specific hip joint exercise program on the characteristics of chronic low back pain (LBP), hip joint range of motion (ROM), and performance level in amateur golfers with LBP. METHODS: The study included 28 adult male amateur golfers with LBP and reduced internal rotation (IR) of the lead side hip joint. Subjects were randomly assigned to an experimental (EG) (n=14) or control group (CG) (n=14). The Numerical Rating Scale score for pain, ROM of the hip joint and trunk rotation, performance parameters for golfing were evaluated. A specific exercise program designed to improve IR of the lead side hip joint was performed by the EG, but not the CG. Post-intervention evaluation was performed and the collected data were analyzed. RESULTS: After the intervention, the severity of LBP was significantly reduced (p<.05) and the IR ROM of the lead side hip joint was significantly increased (p<.01) in the EG. Moreover, the trunk rotation range was significantly increased in the EG (p<.01). The drive distance was significantly difference between the EG and CG (p<.05). CONCLUSION: A specific hip joint exercise program can help to reduce pain level and improve performance level in amateur golfers with LBP and increased IR ROM of the lead side hip joint. A significant increase in ROM of the lead side hip joint reduce LBP and was related to driving distance in the EG.

• 대한교통학회지
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• 제20권5호
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• pp.67-79
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• 2002

교통량, 교통밀도, 교통류 속도 등, 교통류 변수에 대한 현재까지의 불확실한 정의와 연속적 파동방정식의 거시적 교통류 해석상의 문제점을 지적하고 이를 개선하기 위해 교통류 변수들에 대한 새로운 확률적 정의를 제시하고 이들의 성격을 규명하였다. 이러한 새로운 교통류 변수들에 대한 새로운 정의를 바탕으로 미시적 운전자 행동을 세밀하게 수용할 수 있고 많은 교통환경에서 연속적 파동 방정식을 대체하여 교통류 변수들과 통행시간을 예측할 수 있는 미분방정식 체계를 확률 미분방적식을 이용하여 도출하였다. 도출된 미분 방정식을 단일 차량의 시공 괘적에 적용해 보았다.

• Journal of Trauma and Injury
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• 제30권4호
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• pp.126-130
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• 2017

Purpose: Preventable Trauma Death Rate (PTDR) using Trauma and Injury Severity Score (TRISS) has been most widely used as a quality indicator in South Korea. However, this method has a small number of deaths corresponding to the denominator. Therefore, it is difficult to check the change of quality improvement for annual mortality, and there is a disadvantage that variation is severe. Therefore, we attempted to improve the quality of the mortality evaluation by reducing the variation by applying the PARK Index (preventable major trauma death rate, PMTDR) which can increase the number of denominator significantly. And the Save score (S-score) was also examined as another quality indicator. Methods: In the PARK Index, the denominator is number of all patients who have survival probability (Ps) larger than 0.25. Numerator is the number of deaths among these. The PARK Index includes only patients with ISS >15. The S-score is calculated in the same way as the W-score, but the S-score includes only patients with ISS >15, which is a difference from the W-score. Results: PARK Index decreased annually and was 12.9 (37/287) in 2014, 9.6 (33/343) in 2015, and 7.3 (52/709) in 2016. S-score increased annually and was -0.29 in 2014, 4.21 in 2015, and 8.75 in 2016. Conclusions: PARK Index and S-score improved annually. This shows that both quality indicators are improving year by year. PARK Index (PMTDR) has 9.5-fold increase in denominator overall compared to PTDR by TRISS. The S-score used only ISS >15 patients as a denominator. Therefore, there is an advantage that the numerical value change is larger than the W-score. In addition, S-score is not affected by the ratio of major trauma patients to minor trauma patients.