스크린 높이와 서류 고정대 위치에 따른 경부 주위 근육의 활성 정도 비교

권혁철,정동훈,Kwon, Hyuk-Cheol,Jeong, Dong-Hoon 대한물리치료학회 2001 대한물리치료학회지 Vol.13 No.3

Using Video Display Terminals(VDT) in the working environment often causes health complaints in the neck and shoulder region. This study was conducted on ten subjects, in order to investigate the change of electromyographic activities in the neck region(sternocleidomastoid muscle, upper trapezius muscle and erector muscle of cervical spine)with regards to the screen height and document holder position. A total of six different conditions of screen height and document holder position were measured during subjects performed a text-entry task for a duration of 10min. The raw EMG signal was transmuted into the root mean square(RMS). Two-way ANOVA for repeated measures was used to analyse the effects of the two factors. As a result, changing the screen height and document holder position has no effect on electromyographic activities in the neck region.

황산 환경에서 Fe-Si, Ni-Ti계 및 Ni 합금의 내부식성 특성

권혁철,김동진,김홍표,박지연,홍성덕,Kwon, Hyuk-Chul,Kim, Dong-Jin,Kim, Hong-Pyo,Park, Ji-Yeon,Hong, Seong-Deok 한국재료학회 2011 한국재료학회지 Vol.21 No.1

Methods of producing hydrogen include steam reforming, electrochemical decomposition of water, and the SI process. Among these methods, the Sulfur iodine process is one of the most promising processes for hydrogen production. The thermochemical sulfur-iodine (SI) process uses heat from a high-temperature-gas nuclear reactor to produce $H_2$ gas; this process is known for its production of clean energy as it does not emit $CO_2$ from water. But the SI-process takes place in an extremely corrosive environment for the materials. To endure SI environments, the materials for the SI environment will have to have strong corrosion resistance. This work studies the corrosion resistances of the Fe-Si, Ni-Ti and Ni Alloys, which are tested in SI-process environments. Among the SI-process environments, the conditions of boiling sulfuric acid and decomposed sulfuric acid are selected in this study. Before testing in boiling sulfuric acid environments, the specimens of Fe-4.5Si, Fe-6Si, Ni-4.5Si, Ni-Ti-Si-Nb and Ni-Ti-Si-Nb-B are previously given heat treatment at $1000^{\circ}C$ for 48 hrs. The reason for this heat treatment is that those specimens have a passive film on the surface. The specimens are immersed for 3~14 days in 98wt% boiling sulfuric acid. Corrosion rates are measured by using the weight change after immersion. The corrosion rates of the Fe-6Si and Ni-Ti-Si-Nb-B are found to decrease as the time passes. The corrosion rates of Fe-6si and Ni-Ti-Si-Nb-B are measured at 0.056 mm/yr and 0.16 mm/yr, respectively. Hastelloy-X, Alloy 617, Alloy 800H and Haynes 230 are tested in the decomposed sulfuric acid for one day. Alloy 800H was found to show the best corrosion resistance among the materials. The corrosion rate of Alloy 800H is measured at -0.35 mm/yr. In these results, the corrosion resistance of materials depends on the stability of the oxide film formed on the surface. After testing in boiling sulfuric acid and in decomposed sulfuric acid environments, the surfaces and compositions of specimens are analyzed by SEM and EDX.

단일화 기반 의존 문법을 이용한 한국어 분석기

권혁철(Hyuk-Chul Kwon),최준영(Jun-Young Choi) 한국정보과학회 1992 정보과학회논문지 Vol.19 No.5

본 논문은 단일화에 기반한 의존 문법을 사용한 한국어 분석기를 제안한다. 본 논문에서 제안한 파서는 한국어의 특성인 어순의 자유성과 생략을 잘 처리할 수 있는 방법을 제공한다. 본 시스템에서 사용한 의존 문법은 어형상호간의 관계에 기반한 문법으로써 한국어의 특성을 비교적 잘 반영하는 시스템이다. 본 파서는 백트랙킹을 하지 않고, 주어진 입력 문장에 대하여 가능한 모든 파서 트리를 생성한다. 파싱시에 효율을 높이기 위해 자질구조 공유와 지역 중의성 패킹을 사용했다. 본 시스템은 Apollo Workstation에서 C 언어로 구현했다. This paper presents a Korean language parser with a unification-based dependency grammar. Our parser provides an adequate method to deal with word order variability and ellipsis of Korean. It generates all the dependency trees of a sentence. Dependency grammar is used as a basic formalism and parsing technique based on chart is suggested for parsing of governor-final languages. In the implementation of Korean parser, structure sharing and local ambiguity packing are used for computational efficiency. Our System is implemented in Apollo workstation using C programming language.

믿음의 형식 논리적 표현에 관한 연구

권혁철(Hyuk-Chul Kwon),김영택(Yung-Taek Kim) 한국정보과학회 1987 정보과학회논문지 Vol.14 No.2

이 논문은 상황을 고려하여 다수의 지적 시스템의 믿음을 표현하기 위한 문법적 방법에 의한 일차 술어 논리 언어를 제시하고 있다. 제시된 언어의 특성을 분석하고, 이를 바탕으로 컴퓨터에 의한 처리를 가능하게 하기 위하여 언어 자체의 문장에 대한 특성(property)을 대상(object)으로 표현할 수 없도록 제한을 가하고 있다. 그리고 믿음의 특성과 앎과 믿음과의 관계를 분석하고, 상황의 도입에 따른 추가의 믿음의 특성을 반영하는 공리와 논리적으로 앎으로부터 믿음을 추론하는 규칙을 규정하고 있다. This paper gives a syntactic first order predicate language for representation of multiple agents' belief with respect to situations. It also argues the features of the proposed language and imposes limits on the extent to which this language can be used to talk about its own sentences for computational tractability. The characteristics of belief and the relation between belief and knowledge are analyzed. The additional axioms for belief with respect to situations and the logical rules which infer belief from knowledge are defined.

편마비 환자의 기립균형에 영향을 주는 요인에 관한 연구

권혁철(Hyuk Cheol Kwon) 대한물리치료학회 1989 대한물리치료학회지 Vol.1 No.1

The purpose of this study was to determine the factors influencing the standing balance of independent ambulatory hemiparetic patients. The subjects of this study were 30 hemiparetic patients (18 males, 12 females) being treated as admitted or out patients at Severance Hospital Medical Center, all of whom agreed to participate in the study, In order to assure the statistical significance of the results, the paired t-test and a Pearson`s correlation were applied at the .05 level of significance, The results were as follows: 1. The difference in maintenance time of standing balance on a stable and unstable support surface was significant at the .05 level. 2. The difference in maintenance time of standing balance according to the control of visual and acoustic stimuli was singificant at the .05 level. 3. The presence or absence of passive joint motion sense influenced the standing balance maintenance time, 4. There was no significant difference in the maintenance standing balance of the sound tower leg standing conditions according to spasticity, but the paretic lower leg standing conditions were significantly different (p$lt;.05). This type of evaluation should be more widely used in the field of evaluating standing balance with hemiparetic patients, However, more extensive study and reports on various factors of standing balance are needed.

고관절 외전시 중둔근의 근력 및 활동전위 변화에 관한 연구

권혁철(Hyuk Cheol Kwon) 대한물리치료학회 1990 대한물리치료학회지 Vol.2 No.1

The right hip adbuctor musculature has been reported to demonstrate $quot;stretch weakness$quot; attributable to chronic elongation imposed by standing posture common to right-handed healthy persons, Kendall and associates have described the concept of $quot;stretch weakness$quot;. The purpose of this study was to assess isometric hip abduction torque and surface electro-myographic activity (using MYOMED 432) in a sample of 40 healthy right -handed persons (20 male, 20 female), all of whom agreed to participate in the study, and compare side difference in the hip abductor musculature, In order to assure the statistical significance of the results, the paired t-test was applied at the .05 level of significance. The results were as follows: 1. The difference in apparent leg length of right and left legs was significant at the .05 level. 2. There was a significant difference between right and left pelvic height (standing position) at the .005 level measurements, and scapula height at the .05 level. 3. Power measurements and action potentials of right hip adbuctor were greater than the left hip abductor regardless of the range of joint motion (inner range, outer range). 4. The difference in muscle power and action potentials according to inner or outer range of both hip abductor were significant at the .05 level. 5. In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect (p$lt;.005). These results suggest ; In healthy right-handed persons, the apparent leg length on the right is langer than on the left, and pelvic height, is elevated on the right side. Muscle torque and muscle action potentials of the right hip adbuctor are higher than those of the hip abductor in the lengthened position. Therefore, the results in this study are contrary to Kendall`s. This type of study should be carried out in many physical therapy departments.

한국군의 조직문화 차이에 관한 실증적 연구

권혁철(Kwon, Hyuk Chul),이창원(Lee, Chang Won) 서울행정학회 2013 한국사회와 행정연구 Vol.23 No.4

본 연구는 군 전체의 조직문화 특성과 육·해·공군 및 해병대의 조직문화 차이를 진단하여 한국군의 조직문화 변화관리에 필요한 시사점을 찾는데 목적을 두었다. 이를 위해 경잼가치모형(CVF)에 기반을 둔 Cameron & Quinn(1999)의 조직문화평가도구(OCAI)를 활용하였다. 주요 연구결과는 다음과 같다. 첫째, 현재 군 조직문화는 시장지향문화가 가장 강하고 혁신지향문화가 가장 약한 것으로 나타났으나 그 차이가 현격하지 않았다. 군별로는 해군이 시장·위계지향문화가 가장 강했으며 해병대가 가장 낮았다. 둘째, 한국군의 조직구성원들은 관계지향문화를 가장 선호하였으며 그 다음은 혁신지향문화였다. 반면, 시장·위계지향문화는 선호도가 낮았다. 군별로는 해군이 관계·혁신지향문화를 더 많이 선호하였으며 육군이 위계지향문화를 더 선호하는 것으로 나타났다. 셋째, 군 조직구성원들은 시장·위계지향문화는 감소하고 관계·혁신지향문화는 강화되기를 갈망하는 것으로 확인되었으며 군별로는 해군이 가장 강했다. The purpose of this study is to identify features of the Korean military’s organizational culture and dif1erences in organizational culture between the army, navy, air force and the marine corps, and to make recommendations for management changes. Cameron and Quinn’s Organizational Culture Assessment Instrument (OCAI), based on the Competing Values Framework (CVF), is used as the culture assessment tool. Key research findings are as follows: First, while the Korean military organizational culture appears to be generally well balanced, the market is more dominant than adhocracy. To be specific, the navy has the strongest market/hierarchy culture, while the marine corps has the weakest. Second, Korean military officers display most preference for clan culture, followed by adhocracy culture. On the other hand, there is a low preference for market/hierarchy culture. Among the particular branches, navy officers displayed a preference for clan/adhocracy culture, while army officers preferred the market/hierarchy culture. Third, Korean military officers desire a transition in organizational culture from market/hierarchy to clan/adhocracy, and the intensity of this desire was strongest in the navy.

강열점소성 유한요소법을 적용한 봉형상압연 공정설계에서의 공형 설계 및 롤속도 설정

권혁철(H.C.Kwon),김수영(S.Y.Kim),임용택(Y.T.Im) 한국소성가공학회 1999 압연 심포지엄 Vol.1999 No.8

급성치사율시험에서 일정 노출조건 유지를 위한 수용용량법의 적용

권혁철(Hyuck-Chul Kwon),노지연(Ji-Yeon Roh),임동영(Dongyoung Lim),최진희(Jinhee Choi),권정환(Jung-Hwan Kwon) 한국환경독성학회 2011 한국독성학회 심포지움 및 학술발표회 Vol.2011 No.10

고온화학세정환경에서 20 % EDTA 용액이 결함 전열관 (Alloy600)에 미치는 영향

권혁철 ( Hyuk Chul Kwon ) 한국부식방식학회(구 한국부식학회) 2016 Corrosion Science and Technology Vol.15 No.2

The transport and deposition of corrosion products in pressurized water nuclear reactor (PWR) steam generators have led to corrosion (SCC, denting etc.) problems. Lancing, mechanical cleaning and chemical cleaning have been used to reduce these problems. The methods of lancing and mechanical cleaning have limitations in removing corrosion products due to the structure of steam generator tubes. But high temperature chemical cleaning (HTCC) with EDTA is the most effective method to remove corrosion products regardless of the structure. However, EDTA in chemical cleaning aqueous solution and chemical cleaning environments affects the integrity of materials used in steam generators. The nuclear power plants have to perform the pre-test (also called as qualification test (QT)) that confirms the effect on the integrity of materials after HTCC. This is one of the series studies that assess the effect, and this study determines the effects of 20 % EDTA aqueous solution on defective tubes in high temperature chemical cleaning environments. The depth and magnitude of defects in steam generator (SG) tubes were measured by eddy current test (ECT) signals. Surface analysis and magnitude of defects were performed by using SEM/EDS. Corrosion rate was assessed by weight loss of specimens. The ECT signals (potential and depth %) of defective tubes increased marginally. But the lengths of defects, oxides on the surface and weights of specimens did not change. The average corrosion rate of standard corrosion specimens was negligible. But the surfaces on specimens showed traces of etching. The depth of etching showed a range on the nanometer. After comprehensive evaluation of all the results, it is concluded that 20 % EDTA aqueous solution in high temperature chemical cleaning environments does not have a negative effect on defective tubes.