A mathematical model for the waste heat recovery system for an engine was developed. The model based on the experimental data reported before was validated and was used to predict the waste heat recovery and recoverable heat of the engine at various operating conditions of the engine and the system. The model was also used to determine flow rates of the circulating water in the system for a certain temperature increment of the water at various operating conditions of the engine to give basic data to design the system. Stability of the system performance was tested on subjects of vapor lock problem, thermal characteristics of the thermostatic valve, and temperature variation of the circulating water in the engine and fuel consumption of the engine during each mode of the system operation and its change into the other. The test showed that the system operation was stable enough. Temperature profile in the thermal energy storage (TES) was observed during storing thermal energy, and thermal stratification in the TES was well formed acceptable to be used in the system. Finally a scheme to automatize the system was suggested.

본(本) 연구(硏究)는 구동륜(驅動輪)의 러그 설계요인(設計要因)중에 러그 테이퍼각(角), 러그각(角) 및 러그폭(幅)등이 토양반력(土壤反力)에 미치는 영향(影響)을 구명(究明)하기 위하여 모형실험장치(模型實驗裝置)를 제작(製作)하고 모래지반(地盤)의 토양조(土壤槽)를 이용(利用)하여 실험한 결과 다음과 같이 요약(要約)되었다. 1. 설정(設定)슬립이 증가(增加)할수록 토양반력(土壤反力)의 수평분력(水平分力)은 증가하였다. 2. 러그 테이퍼각(角)은 $23^{\circ}$까지 증가할수록 주행성향상(走行性向上)에 그 효과가 큰 것으로 나타났다. 3. 러그각(角)은 주행성향상(走行性向上)에 그 효과가 인정되며 $60{\sim}74^{\circ}$가 적절(適切)한 것으로 나타났다. 4. 러그폭(幅)은 20~30mm까지 토양반력(土壤反力)의 수평분력(水平分力)에는 큰 영향(影響)을 주지 못했다.

Major rice grain losses both in quality and in quantity are incurred in the whitening process which is indispensable in the milling process. Rice whitening it performed by two different whitening actions known as abrasive and frictional. In Korea, abrasive-type whiteners equipped with a emery-stone roller have been adopted in the whitening system in large scale milling plants, but not in customary small scale. However, researches on this type whitener have rarely been conducted in Korea. This study was attempted to establish design criteria or a modified abrasive-type whitener which is aerated with blower. The factors considered in this study were three levels of feedscrew pitch (20, 27, 34 mm) and three levels of clearance(11, 13, 15 mm) between surfaces or emery-stone roller and screen and two levels of moisture content (14.5%, 15.7%, w.b.) of brown rice. Also, the effect of aeration on whitening performance was examined, and a system performance consisting of one pass in the aerated abrasive-type and two passes in the existing friction type was compared with the performance of the existing whitening system consisting of three passes in friction type only. The latter system is prevailed in customery small milling plants. The results of this study are summarized as follows. 1. The interactions between feed-screw pitch and chamber clearance of the aerated abrasive-type whitener had great effect on the performance of the machine. When the value of a nondimensional parameter, $C^2/(P{\cdot}d_p)$, expressing the relations between feed-screw pitch, P, and chamber clearance, C, ranged from 0.40 to 0.45, the performance of the aerated abrasive-type whitener was the best. 2. Aeration to the abrasive-type whitener gave positive effect on milled and head rice recoveries. 3. The whitening system involving the aerated abrasive-type whitener, which has appropriate feed-screw pitch and chamber clearance as described in item 1 above, produced more milled and head rice recoveries by about 1.5% and 2.0%, respectively, than the existing frictional whitening system. The former also consumed less electricity by about 10% (0.9KwH/1000kg).

In order to improve the traditional post harvest system in Korea, a model for mechanized rice drying and storage system was developed and introduced as the first part of the study(Park, 1986). As the second part of the study, capital requirement and cost of the model system was analyzed. Also, optimum size of the model system was estimated by comparing with the traditional harvest system. From the study, the following results can be concluded: 1. The capital requirement of the model system decreases as the model size increases. For example, a model system having 500 ton storage capacity requires 439,000 Won/ton. However it requires 313,200 Won/ton only, if the model size increases to 1000 ton. 2. Also, total cost of the model system decreases as the model size increases. For example, total costs of the model system having 500 ton and 1000 ton storage capacity are 101,208 Won/ton and 69,320 Won/ton, respectively. 3. The breakeven point (optimum size) of the model can be estimated around 630 ton storage capacity if the operation rate is assumed as 100%. However, the optimum size of the model is 710 ton, if the operation rate it assumed 80%.

Measurement methods of moisture content were compared with 7 dried vegetables (red pepper, onion, green onion, garlic, ginger, carrot and radish). The moisture contents of dried vegetables having different moisture contents were determined by atmospheric oven drying, infrared balance, vacuum oven and Karl Fisher methods. Vacuum oven and Karl Fisher methods gave the relatively agreed results and considered to give the accurate moisture content. Atmospheric oven drying and infrared balance methods resulted in higher moisture content than methods mentioned above, because of the thermal decomposition of solid. Calibration of the moisture data of atmospheric oven drying method into the vacuum oven data was undertaken. The thermodecomposable solid fraction was high in onion, radish, green onion and carrot, and was in the range of 8.0-11.7% of the total solid in these products.

엔진의 점화시기(點火時期)를 제어(制御)하는 데에 마이크로컴퓨터를 이용(利用)하고자 여러 종류(種類)의 제어장치(制御裝置)를 설계(設計) 제작(製作)하여 가동시험한 결과를 요약하면 다음과 같다. 가. 제어장치(制御裝置)의 제작시(製作時) 고압방전(高壓放電)에 의한 잡음(雜音), 서어지, 전자파(電磁波)로부터 디지탈회로와 컴퓨터의 기능(技能)이 교란되는 것을 방지하기 위하여는 고압회로(高壓回路)와 여타 회로와의 분리 및 고압회로의 기생발진 억제와 차폐가 완전하여야 할 것이며, 또한 양질의 점화용(點火用) 도선(導線)을 사용하여야 할 것으로 생각된다. 나. 본 실험의 범위내에서는(컴퓨터시스템) (써어보 기구에 의한 점화신호발생(點火信號發生) 및 제어(制御) - (트랜지스터 스위칭) - (고압회로) 로 구성(構成)시킨 점화시기제어장치가 컴퓨터 등의 기능교란을 일으키지 않고 가장 잘 작동(作動)되었다. 다. 본 실험의 결과(結果)를 기초(基礎)로 마이크로컴퓨터를 이용한 엔진의 최적점화진각제어(最適點火進角制御)에의 응용(應用)이 가능(可能)할 것으로 사료(思料)된다.

우리나라는 지난 20년간(年間) 농촌노동력(農村勞動力)의 급격(急激)한 감소(減少)로 동력경운기(動力耕耘機), 이앙기(移秧機), 바인더 등의 농업기계(農業機械)가 대량(大量)으로 보급(普及)되어 수도작(水稻作)의 경우 대부분(大部分)의 농작업(農作業)이 기계화(機械化)되었다. 앞으로 계속적인 농촌노동력(農村勞動力)의 감소(減少)와 더불어 현재(現在)의 동력경운기(動力耕耘機) 중심(中心)의 소형기계화체계(小型機械化體系)는 잉용(剩用) 트랙터 중심(中心)의 대형기계화체계(大型機械化體系)로 발전(發展)될 것이다. 이와 더불어 전자공업(電子工業)의 발달(發達)은 농업기계(農業機械)의 자동화(自動化)를 촉진(促進)시킬 것이 확실(確實)하며 그 전망(展望)과 방향(方向)을 요약(要約)하면 다음과 같다. 1. 농업기계(農業機械)의 자동화(自動化)는 작업능률(作業能率) 및 작업정도(作業精度)의 향상(向上), 자원(資源) 및 에너지절약(節約), 농업노동력(農業勞動力)의 부족해소(不足解消), 작업자(作業者)의 부담경감(負擔輕減) 및 안전성(安全性) 향상(向上)을 위하여 도입(導入)되어야할 첨단기술(尖端技術)이다. 2) 농업기계(農業機械)의 자동화(自動化)는 전자공업(電子工業)의 급속(急速)한 발전(發展)에 따라 기계(機械)의 부분(部分) 자동화(自動化)로부터 궁극적(窮極的)으로 무인조종기계(無人操縱機械) 또는 농업용(農業用) 로보트로 발전(發展)되어 농업(農業)은 고도(高度)의 기술산업(技術産業)으로 전환(轉換)될 것이다. 3) 농업기계(農業機械)의 자동화(自動化)는 농가(農家)의 경제적(經濟的) 부담(負擔)을 줄이고 농업노동력(農業勞動力)을 배제(排除)하지 않도록 단계적(段階的)으로 추진(推進)되어야 한다. 또한 자동화(自動化)에 의하여 노동의욕(勞動意慾)이 감퇴(減退)되거나 인간성(人間性)이 상실(喪失)되는 일이 없어야 할 것이다. 4) 합리적(合理的)인 농업기계(農業機械)의 자동화(自動化)를 위하여 농업(農業)의 대상(對象)인 작물(作物)과 토양(土壤)의 특성(特性)을 구명(究明)하고, 이를 검출(檢出)할 수 있는 센서와 이를 이용(利用)한 제어장치(制御裝置)의 개발(開發)이 필요(必要)하다. 또한 완전자동화(完全自動化)를 위하여 인공지능(人工知能)을 갖는 농업용(農業用) 로보트에 대한 연구개발(硏究開發)이 요구(要求)된다. 5) 기존(旣存)의 개별(個別) 농업기계(農業機械)를 단순(單純)히 자동화(自動化)하려는 고정개념(固定槪念)으로부터 탈피하여 농작업(農作業) 전체(全體)를 포함(包含)한 조화(調和)된 자동화(自動化) 시스템 개발(開發)에 노력(努力)하여야 할 것이다.