• PNF and Movement
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• 제22권1호
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• pp.31-41
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• 2024

Purpose: The purpose of this study is to compare lower extremity muscle activities and ankle joint angles between different foot strike patterns (forefoot strike, heelfoot strike) during stair ascent walking. Methods: The subjects of this study were 22 males who walked in each foot strike pattern on ascent stairs at a speed of 85 beats/min. During stair walking with the two types of foot strike patterns, the muscle activities of the rectus femoris, tibialis anterior, medial gastrocnemius, hamstring, and gluteus medius were measured. Additionally, ankle joint angles for inversion, eversion, dorsi flexion, and plantar flexion were recorded. Each participant underwent the experiment three times, with the foot strike pattern randomized. Results were averaged according to the foot strike pattern. Results: Significant differences in ankle angles were observed across all phases according to foot strike pattern. Muscle activities in the lower extremities showed significant differences in all phases except the swing 1 phase. Moreover, differences in foot movement trajectory were noted depending on the foot strike pattern. Conclusion: Walking on ascent stairs elicited differences in lower extremity muscle activities and ankle joint angles based on foot strike pattern. These findings can serve as foundational data for selecting a suitable foot strike pattern tailored to individual patient conditions when training patients in walking on ascent stairs.

• 보건의료산업학회지
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• 제8권2호
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• pp.23-35
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• 2014

The aim of this study is to analyze determinant factor on the strike action among hospital laborer in Korea. We collected data for 10days from 12 to 22 July, 2013. This study was surveyed 405 laborer in university hospital was located in the Seoul city and Gyeonggi-do. It was found as follow. There was statistically significant difference in the strike propensity and sub-domain on the job dissatisfaction by sex, age, education, wedding, occupation, position, salary, number of years of employment, position in labor union for strike action(p<0.05). From the multiple regression analysis, it was found that determinant factor on the strike action was occupation, strike propensity(sense of duty, after vote, depend on compensation) which was statistically significant difference(p<0.05). As a result, we suggest that hospital administrator must solve the problem related welfare benefits and personnel system in university hospital for preventing strike.

• 한국항공운항학회지
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• 제17권4호
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• pp.85-93
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• 2009

Bird strike is big issue in aviation. Because a bird strike causes not only an aircraft damage but also a fatality, aviation societies are gearing up to prevent a bird strike. However, the accidents is not going down yet. Annal average of bird strikes in Korea is 1.15 accidents per ten thousand of flight, which is lower than the other country, for example 1.84 accidents in France and 2.38 accidents in Switzerland, 1.15 accidents. In the U.S.A, there are 89,727 accidents for the 19 year(1990-2008). Also flight delay is total 637,692 hours. The cost is total 350,258 billion dollar and 18,435 billion dollar per year. In related with those data's, this research is about the current and legal status of the bird strike. Also it will be useful to establish aviation safety policy and manage the bird strike.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 추계 학술발표회 논문집
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• pp.153-158
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• 2005

A floating-strike lookback call option gives the holder the right to buy at the lowest price of the underlying asset. Similarly, a floating-strike lookback put option gives the holder the right to sell at the highest price. This paper will derive explicit pricing formulas for these floating-strike lookback options with flexible monitoring periods. The monitoring periods of these options start at an arbitrary date and end at another arbitrary date before maturity.

• 한국운동역학회지
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• 제33권4호
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• pp.164-174
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• 2023

Objective: The aim of this study was to quantitatively analyze the impact characteristics of the lower extremity on strike pattern during running. Method: 19 young subjects (age: 26.53 ± 5.24 yrs., height: 174.89 ± 4.75 cm, weight: 70.97 ± 5.97 kg) participated in this study. All subjects performed treadmill running with fore-foot strike (FFS), mid-foot strike (MFS), and rear-foot strike (RFS) to analyze the impact characteristics in the lower extremity. Impact variables were analyzed including vertical ground reaction force, lower extremity joint moments, impact acceleration, and impact shock. Accelerometers for measuring impact acceleration and impact shock were attached to the heel, distal tibia, proximal tibia, and 50% point of the femur. Results: The peak vertical force and loading rate in passive portion were significantly higher in MFS and FFS compared to FFS. The peak plantarflexion moment at the ankle joint was significantly higher in the FFS compared to the MFS and RFS, while the peak extension moment at the knee joint was significantly higher in the RFS compared to the MFS and FFS. The resultant impact acceleration was significantly higher in FFS and MFS than in RFS at the foot and distal tibia, and MFS was significantly higher than FFS at the proximal tibia. In impact shock, FFS and MFS were significantly higher than RFS at the foot, distal tibia, and proximal tibia. Conclusion: Running with 3 strike patterns (FFS, MFS, and RFS) show different impact characteristics which may lead to an increased risk of running-related injuries (RRI). However, through the results of this study, it is possible to understand the characteristics of impact on strike patterns, and to explore preventive measures for injuries. To reduce the incidence of RRI, it is crucial to first identify one's strike pattern and then seek appropriate alternatives (such as reducing impact force and strengthening relevant muscles) on that strike pattern.

• 응용통계연구
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• 제22권1호
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• pp.59-73
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• 2009

A floating-strike lookback call option gives the holder the right to buy at the lowest price of the underlying asset. Similarly, a floating-strike lookback put option gives the holder the right to sell at the highest price. This paper will propose an outside floating-strike lookback call (or put) option that gives the holder the right to buy (or sell) one underlying asset at some percentage of the lowest (or highest) price of the other underlying asset. In addition, this paper will derive explicit pricing formulas for these outside floating-strike lookback options. Sections 3 and 4 assume that the underlying assets pay no dividends. In contrast, Section 5 will derive explicit pricing formulas for these options when their underlying assets pay dividends continuously at a rate proportional to their prices. Some numerical examples will be discussed.

• 한국항공운항학회지
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• 제27권2호
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• pp.16-25
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• 2019

While various efforts are being made to ensure aviation safety, air accident rate induced by pilot human factors is still high worldwide. In particular, among pilot human factors, it would be the most important issue for pilots to anticipate and recognize flight environmental factors beyond their control and to make a positive decision making(ADM). In the Republic of Korea Air Force(ROKAF), there were many dizzying experiences induced by bird strike incidents and developed into dangerous moments such as damage to the aircraft and pilots' increased mental stress. It is a matter of serious concern in terms of safety management and human factors to dismiss bird strike incidents as inevitable misfortune due to environmental factors. In 2018, the ROKAF Aviation Safety Agency(ASA) conducted an experimental study to enhance pilots' ADM competence that can anticipate and avoid a bird strike. As the way of the study, 'Bird Strike Preventing Information' had been written and distributed every week by the ASA to flight units in the ROKAF during the period of the study. Through enhanced pilots' perceptual ADM competence, there was a noticeable number of reduction in bird strike incident compared to previous years of the experimental study.

• 한국병원경영학회지
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• 제14권1호
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• pp.123-144
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• 2009

Recently, a long strike by hospital labor union emerged as a serious social issue. During the Worldcup Games in June, 2002, labor strikes broke up at 'C', 'K' and other hospitals, and in 2007, 'Y' hospital suffered much from a strike. Such series of extreme labor disputes have awakened people of importance of a more stable labor-management relationship for the medical institutions responsible for people's health than any other business organization. The purpose of this study was to examine the labor-management disputes at 'Y' hospital in 2007 and 'C' and 'K' hospitals in 2002. The results of this study can be summarized as follows; First, requests of the labor union such as pay raise, reemployment of the irregular workers as regular employees and participation of the labor union in personnel affairs are the long-held or core issues suffered by the medical institutions. Such issues are not independent from each other but complicated with each other surrounding the pay raise. Accordingly, it is not easy to determine the genuine bone of issue for labor-management disputes. Second, the model type of disputes between labor and management at medical institutions may be strike. However, it is conceived that the type of disputes would be subject to change as the essential medical service area system began to be operated since 2008. Third, the common characteristic of the labor strike among the 3 sample hospitals was occupation of the hospital lobby for a sit-in strike to maximize the negative effects of strike. Article 42 (Prohibition of Violence) of Labor Union and Labor Relation Coordination Act prohibits occupation of production or other important business facilities. In addition, since Ministry of Labor interprets that the hospital lobby belongs to the important business facilities enumerated by Article 42 of the above act, occupation of the hospital lobby for a sit-in strike may be too controversial to be admitted as a fair act of labor dispute when its legitimacy should be judged. Fourth, the counter-measures taken by the hospitals against the strike were observance of the principle 'no labor no pay,' closure, legal action, accusation, claim for recovery of damage, provisional seizure, disciplinary punishment, etc., but the principle of 'no labor, no pay' was not applied in a fair manner by 'C' and 'K' hospitals. However, 'Y' hospital applied this principle thoroughly to the strike; the hospital conduced to correction of the wrong labor-management relationship by refusing inclusion in the labor collective agreement of a provision about payment of wage during the period of strike or labor union's request to that effect during a strike. In addition, 'Y' hospital took an effective measure to end the strike earlier by notifying the labor union of cancellation of the collective agreement and banning the unionists from entering the hospital.

• 한국항공운항학회지
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• 제17권2호
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• pp.68-71
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• 2009

In this paper, we presented the cases of tail strike of KAIRS, which is useful to establish the methods to decrease a risk, aircraft operation viewpoint.

• 지질공학
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• 제13권3호
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• pp.321-334
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• 2003

본 연구는 암반에서 불연속면 방향의 효율적인 측정 방안에 관한 것이다. 불연속면의 방향성은 주향/경사, 경사방향/경사(세 자리 숫자/두 자리 숫자) 그리고 경사방향을 우측에 두고 바라보는 방향을 주향방향으로 결정하는 방법의 세 가지 방법으로 표현한다. 일반적으로 불연속면의 주향/경사는 클리노미터에 의해 측정이 되며, 경사방향』경사는 실바콤파스(type15)에 의해 측정된다. 주향/경사는 지질조사시에 측정이 되는데, 경사방향/경사는 공학적 목적으로 측정이 되며, 통계처리에 유용하다 클리노미터에 의해 불연속면의 경사방향 측정과 주향/경사를 경사방향/경사로의 전환 시, 측정자에 따라 오류를 유발할 가능성이 있다. 본 연구에서는 불연속면 방향성을 두 가지 방법 (주향/경사. 경사방향/경사)으로 효과적으로 측정하기 위하여 클리노미터에 회전방위판과 주향 및 경사방향 표시 화살표를 부착하여 측정하는 방법을 고안하였다. 이 새로운 측정법은 주향뿐만 아니라 경사방향을 정확하게 측정할 수 있는 효과적인 측정법이다. 또한 이 측정법은 주향/경사 및 경사방향/경사의 동시 측정이 가능하다. 암반사면에서 불연속면의 방향 측정 시, 현행 측정법과 새로운 측정법을 비교한 결과. 새로운 측정법이 오류를 분명히 감소시킴을 알 수 있었다 따라서 새로운 측정법은 도로 설계 시 광역적인 지표지질조사에서 많은 불연속면의 방향성을 측정할 경우와 측정 경험이 부족한 조사자에게 유용한 방법이라고 생각된다.