內燃機關의 吸入空氣流量 測定에 관한 硏究

하종률,이상석,여종구,이동희 동아대학교 공과대학 부설 한국자원개발연구소 1991 硏究報告 Vol.15 No.1

In this study, thr air flow-meter was developed which can control the air flow rate with the load of the engine and to measure air flow rate using Karman vortex. In the experiment, the sensor consists of an air channel with a triangular strut(bluff body) to generate the Karman vortex street, a couple of ultrasonic transmitter and receiver, to detect vortex. The results obtained from these experiments are as follows;air flow rate can be measured by detecting Karman vortex with ultrasonic sensors, vortex frequency is linearly proportion to the air flow rate. To measure air flow rate, the width of bluff body and the number of stability plate used in air flow rate sensor are 7㎜ and 2. Air flow sensor developed at this experiment can be used for Internal combustion engine, and for various purposes, too.

이종연료 층상분사를 이용한 디젤엔진을 NOx와 soot동시 저감에 관한 연구(제2보)

하종률,강병무,안현찬,이태원,윤수한 東亞大學校 2001 東亞論叢 Vol.38 No.-

To investigate the method of the simultaneous reduction of Soot and NOx, we developed a new conception for dual fuel stratified injection system in a Diesel Engine. Some parts of the injection system, ie. nozzle holder, delivery vale, were remodeled to inject diesel and methanol in order from one injector. The quantity of diesel and methanol was controled precisely by micrometers that were mounted at control lack of injection pump. The real injection quantity ratio of dual fuel was certificated by volumetric ratio at injection Quantity experiment. We could confirm the capability that soot and NOx simultaneously were reduced by diesel-methanol stratified injection from the results of combustion and exhaust characteristic.

디이젤 噴霧 周圍氣體의 엔트레인먼트에 관한 實驗的 硏究

하종률,김봉곤 대한기계학회 1988 대한기계학회논문집 Vol.12 No.3

본 연구에서는 디이젤분무 주위기체의 유동특성중에서 유동속도에 관하여 보 고 하였다. 본모에서는 분무기간중 분사압력의 시간경과특성이 상이한 두 종류의 분 사계를 사용하여 생성된 분무와 주위 기체와의 유동방향의 시간경과 및 유입시기, 정 상유입속도 도달시간등을 분무의 축방향과 반경방향에 대하여 상세한 측정결과를 얻었 기에 보고한다. A study on the mixing process of fuel with ambient gas is necessary to verify combustion process of a diesel engine, especially the mechanism of its ignition delay. In this study, a single shot of diesel spray was injected through either a constant pressure injection system and bypass type injection system. Measurements were made on the flow characteristics of ambient gas and its time history using a hot wire anemometer and a high speed camera. The gas flow direction was determined by a smoke tracer method. (1) The ambient gas of spray flows away at the stagnation part where static pressure value is positive and flows in at the penetration part of a negative value with the steady entrainment length of 0.7. (2) The steady entertainment velocity around the spray in creases from the nozzle tip to the downstream, has the maximum value at the mixing boundary part, and represents zero at the stagnation boundary part after which the stream flows reversely at the stagnation part.

고객의 팁핑에 대한 인식 및 행동 연구: 일식 레스토랑을 중심으로

하종률,차석빈 한국외식경영학회 2013 외식경영연구 Vol.16 No.6

Little research with related to customers' tipping behaviors in the Japanese restaurant segment in Korea where customers' tipping is common has been carried out. This study is to compare the perception toward tipping between tipping-oriented group and non tipping-oriented group and the former's tipping behaviors. Research findings are as follows. First, in terms of tipping orientation between the above two groups, statistically significant differences were found in the variables of marital status, age, job, type of restaurant visited, purpose of visit, accompanying company, and average cost for dinner per person. Tipping-oriented group put high importance on 'higher quality of service' for tipping while nontipping-oriented groups put on 'pressure on expense' and 'unnecessity of tip because it is included in the price'. Motivations of customers' tipping were centered on employees' attitude while ones for no-tipping were on the no-tip cultures in our society. It turned out that tipping-oriented group gave 10,000-20,000 won to hall or kitchen employees during dinner time. Finally, after tipping, tipping-oriented group had positive impressions such as employees' kind and prompt service and special services. 기존의 국내 팁 관련 연구가 주로 호텔기업과 직원대상으로 이루어져 팁핑이 공공연히 이루어지고 있는 일식 레스토랑의 연구는 전무한 실정이다. 본 연구는 이러한 기존 연구의 한계점을 인식하여 일식 레스토랑 고객을 대상으로 팁핑 경향이 있는 집단과 미팁핑 경향이 있는 집단으로 나누어 이들의 팁에 대한 인식과 팁핑 행동을 비교 분석하였다. 분석결과, 첫째, 표본의 인구통계학적 특성에 따른 팁핑 경향여부에서는 결혼여부, 연령, 직업에서, 둘째, 표본의 일식 레스토랑 이용형태에 따른 팁핑 경향여부에서는 이용 레스토랑 형태, 이용목적, 동반상대 및 1인당 평균비용에서 통계적으로 유의한 차이가 있는 것으로 나타났다. 셋째, 팁핑 인식차이에서는 팁핑 경향집단이 ‘봉사료제도 선호’와 ‘질 높은 서비스를 위해 필요’하다는 부분에서, 미팁핑 경향집단은 ‘상품가격에 포함되므로 불필요’하다는 부분에서 더 높은 평균점을 보여주었다. 넷째, 팁핑의 이유로 ‘직원의 세심한 배려, 직원의 친절, 신속한 서비스 등 주로 직원의 태도에 기인하는 것으로 나타난 반면, 미팁핑 이유로는 음식가격에 봉사료가 포함, 사회적으로 팁을 안주는 분위기, 금전적으로 아까움 순으로 높게 나타나 팁 문화가 없는 국내의 사회적 분위기가 많은 영향을 미친 것으로 분석되었다. 다섯째, 팁핑 경향집단은 팁을 ‘식사 중’에 주로 홀 서빙 직원과 주방 직원(주방장 포함)에게 현금으로 1∼2만원 정도의 팁을 주는 것으로 나타났다. 마지막으로 팁핑 경향집단은 팁핑이 이루어진 직후 직원이 더 친절해지는 등 긍정적인 인식을 하였으며, 전반적으로 만족감을 보이는 것으로 분석되었다.

독립경영 외식업 성공요인이 경영성과에 영향을 미치는 영향 - 현장 경험의 조절효과를 중심으로 -

하종률,차석빈 동북아관광학회 2017 동북아관광연구 Vol.13 No.4

본 연구는 현장경험을 독립변수로 사용한 기존 연구와 달리 조절변수로 사용하여 2년 이상 운영하고 있는 독립경영 외식업 경영자를 대상으로 이들의 외식업 성공요인이 경영성과에 미치는 영향을 살펴본 후 성공요인과 경영성과 간 관계에서 현장 경험의 조절효과를 검증하고자 했다. 주요 연구결과는 다음과 같다. 첫째, 외식업 성공요인 중 성취, 창의혁신, 마케팅, 조직화 요인은 재무적 경영성과에 정(+)의 영향을, 서비스요인과 메뉴관리요인은 비재무적 경영성과에 정(+)의 영향을 미치고 있는 것으로 나타났다. 둘째, 근무경험이 있는 집단은 성취, 창의혁신, 조직화요인이 재무적 경영성과에 정(+)의 영향을, 창의혁신요인과 서비스요인은 비재무적 경영성과에 정(+)의 영향을 미치는 것으로 분석되었다. 반면 근무경험이 없는 집단은 위험감수요인이 재무적 경영성과에 부(-)의 영향을, 창의혁신요인은 정(+)의 영향을 미치는 것으로 분석되었다. 마지막으로, 외식업분야의 근무경험 집단은 서비스, 메뉴관리, 조직화요인이 재무적 경영성과에 정(+)의 영향을, 메뉴관리요인과 조직화요인이 비재무적 경영성과에 정(+)의 영향을 미치는 것으로 분석되었다. 반면, 비외식업분야 근무경험 집단은 창의혁신요인이 재무적 경영성과에 정(+)의 영향을 나타냈다. Comparing with the previous studies using field experience as an independent variable, this study was conducted to verify the success factors of independently managed food service businesses on their management performances and moderating role of field experience in the relationship between success factors and management performances. The results of the study showed that achievement, creativity and innovation, and systemization factors had positive influences on financial management performances while service and menu management factors had positive influences on non-financial management performances. In relation to the moderating effect of experiences between the success factors and management performance according to field experience, for the group with prior work experiences, achievement, creativity and innovation, and systemization factors had positive influences on financial performance while creativity, innovation, service factors had positive influences on non-financial one. For the group without prior work experiences, risk taking factor had negative influences on financial performance and creativity and innovation factors had positive influences on financial performance. In relation to the moderating effect between the success factors and management performances according to working fields, the group with prior work experience in the food service field showed that service, menu management, and systemization factors had positive influences on the financial performance while menu management and systemization factors had positive influences on the non-financial one. For the group with prior work experience in fields other than food service, creativity and innovation factors had positive impact on the financial management.

EFFECTS OF THE THROTTLE OPENING RATIO AND THE INJECTION TIMING OF CNG ON THE COMBUSTION CHARACTERISTICS OF A DI ENGINE

하종률,박종상,강정호 한국자동차공학회 2010 International journal of automotive technology Vol.11 No.1

We investigated the effects of the fuel injection timing - both for early and late injection - in conjunction with the throttle opening ratio on the fuel-air mixing characteristics, engine power, combustion stability and emission characteristics of a DI CNG spark engine and control system that had been modified and designed according to the author’s original idea. We verified that the combustion characteristics were affected by the fuel injection timing and that the engine conditions were affected by the throttle opening ratios and the rpm. The combustion characteristics were greatly improved for a complete open throttle ratio with an early injection timing and for a partial throttle ratio with a late injection timing. The combustion duration was governed by the duration of flame propagation in late injection timing scenarios and by the duration of early flame development in cases of early injection timing. As the result, the combustion duration is shortened, the lean limit is improved, the air-fuel mixing conditions are controlled, and the emissions are reduced through control of the fuel injection timing and vary according to ratio of the throttle opening.

直憤式 디이젤機關의 出力性能 및 排出微粒子에 미치는 吸氣 濕度의 影響에 관한 硏究

하종률,탁영조,정대간 동아대학교 환경문제연구소 1988 硏究報告 Vol.11 No.1

The engine output and particulate emission are influenced by inlet air humidity. This study is concerned with the engine output and particulate emission on the inlet air humidity. The engine performance was analized to P-θ diagram, the rate of pressure rised, the rate of heat release, and the rate of mass burned by means of combustion analysis system. The particulate emission measurement is made by mini-dilution tunnel system. Consequently, this study showes the qualitative relationship between the engine output or particulate emission and the inlet air humidity.

정적연소기에서 혼합기 유동과 점화에너지의 최적화에 관한 연구

하종률(Ha Jong-Yul),이중순(Lee Jung-Soon) 한국자동차공학회 1993 한국자동차공학회 학술강연초록집 Vol.- No.-

[부문위원회 소개]디젤엔진 부문위원회 소개

하종률(Jong Yul Ha),배충식(Choongsik Bae) 한국자동차공학회 2003 오토저널 Vol.25 No.1

[참관기]2002 FISITA를 다녀와서

하종률(Jong Yul Ha) 한국자동차공학회 2003 오토저널 Vol.25 No.2