• 반도체디스플레이기술학회지
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• 제20권1호
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• pp.42-47
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• 2021

In this study, we developed an application that can efficiently store and manage food ingredients in refrigerators. Rather than purchasing a new smart refrigerator, a small 'pocket scanner' is inserted inside the refrigerator using an existing refrigerator to track the location of food entering and leaving the refrigerator to efficiently organize the refrigerator and save time searching for ingredients. In addition, since it can automatically record the distribution period and purchase date, it notifies users through an alarm when the distribution period expires or is shortly left. As for the research method, after discovering the needs of users through in-depth interviews, the reactions of users were investigated by adding functions that fit those needs. Users felt satisfied with managing food efficiently through the 'pocket scanner' attached to the refrigerator and answered that it was very economical because various smart functions could be used without changing to a smart refrigerator. In the next study, we will also examine the usability of the application through usability evaluation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.253-256
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• 2004

Acoustical noise at low frequency range (below 500Hz) of refrigerator result from fans which are inside of the refrigerator. In generally to evaluate and apply to refrigerator it is recommended that acoustical noise and fluidic performance of the fan were measured simultaneously. To do that twin-room type anechoic wind tunnel was needed. But constructing twin room type anechoic wind tunnel was very expensive and estimation of small refrigerator fan performance was not easy. So in this paper we composed anechoic fan tester. A successful noise and performance measurement was performed using the anechoic fan tester. Existing 22 kinds of refrigerator fan were investigated and mapped into one database. Refrigerator duct pressure resistance were measured and reflected into the fan database to find out appropriate fan. Through the application of fan database, the refrigerator became less noise compared to current one and these data shows what is the best way to reduce fan noise.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.159-162
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• 2003

Cooling with easy, reliable cryocooler is highly desirable for the commercial and military application The pulse tube refrigerator has no moving parts at the cold end, so that the mechanical vibration and magnetic noise can be reduced to the low level with higher relaibility and longer lifetime than the Stilting cryocooler. The inertance tube improve the performance of pulse tube refrigerator by providing optimal phase shift between pressure and amss flow rate, and it is easiest to implement at large cooling capacity and high operating frequency. In this study, the performance of the inertance pulse tube refrigerator was investigated by analysis. The results show the influence of the diameter and length of the inertance tube on the performance of the refrigerator.

• 연구논문집
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• 통권24호
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• pp.27-39
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• 1994

lower vibration than in any other small refrigerators. The experimental results of three types of pulse tube refrigerators are presented in this paper. The objectives of this study are to develop the design technology of the double inlet pulse tube refrigerator and acquire its application method. As a preliminary experiment, the refrigeration performances of the basic, orifice and double inlet pulse tube refrigerator were investigated. The lowest temperature obtained in this experiment was 34.4K. The refrigeration capacity at the optimum operating condition of the double inlet pulse tube refrigerator was 23W at 80K.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.639-644
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• 2002

In this paper, a successful noise reduction of an axial flow fan for a refrigerator is presented. The vortex sheet generated at the blade tip of fan was suppressed by changing the shape of the tip. The structure of vortex sheet and detailed flow pattern around the fan were studied by two-dimensional LDV(Laser-Doppler Velocimetry). Effective ways to work out the result as mentioned above are to make the tip of the blade varied in thickness and to have elliptical shapes. To seek the optimal value fur the shape of new fan, several cases were examined. Through the application of the methods, the refrigerator became less noisy by 3.8 dB(A) in terms of air-borne noise produced only by the axial flow fan compared to the current one.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.570-572
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• 2015

NFC(Near Field Communication)는 근거리 무선 통신의 일종으로 RFID 기술의 한 영역이다. NFC 기술은 데이터 전송, 출입통제 시스템 활용 및 모바일 결제와 같은 많은 영역에서 유용하게 사용되고 있다. 최근 NFC를 활용한 스마트폰 어플리케이션 개발이 활성화되고 있지만, 현재 NFC 태그의 편리성에 대한 인식은 미미한 상태이다. 본 논문은 마트를 방문하는 고객에게 편리성과 식품에 대한 지식을 제공하기 위해 만든 Application에 대한 내용이다. 사용자는 마트에서 스마트폰을 이용하여 식품 전시대에 붙어있는 NFC에 태그하게 되면 식품정보, 구입요령, 보관법, 효능 등의 데이터가 스마트폰 화면을 통해 제공된다. 해당 식품을 구매할 경우 '냉장고에 넣기' 버튼 클릭 시 Application의 식품목록으로 넘어가며, 식품목록 화면을 통해 자신의 냉장고안의 식품목록, 유통기한 등의 정보를 제공함으로써 사용자들이 좀 더 편리하게 식품을 구매할 수 있도록 도와준다.

• 한국초전도ㆍ저온공학회논문지
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• 제6권2호
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• pp.40-45
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• 2004

The experimental results of the G-M (Gifford-McMahon) type pulse tube refrigerators are presented in this paper. The pulse tube refrigerator, which has no moving parts at its cold section, is attractive in obtaining higher reliability, simpler construction, and lower vibration than any other small refrigerators. The objectives of this study are to develop the design technology of the G-M type pulse tube refrigerator and acquire its application methods for replacing G-M cryocooler. As a preliminary test, the refrigeration performances of the basic, orifice, and double inlet pulse tube refrigerators were investigated. The lowest temperature obtained in the one-stage pulse tube refrigerator was 34.4K and the refrigeration capacity at the optimum operation condition was 23W at 80K. And the lowest temperature of the second stage cold head in the two-stage pulse tube refrigerators was 18.3K and the refrigeration capacities at optimum condition were 0.45W at 20K and 20W at 80K, respectively. Finally, the lowest temperature obtained in the three-stage pulse tube refrigerator was 29.8K and the refrigeration capacity at the optimum operation condition was 1.3W for 40K and 5W for 70K.

• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.1-8
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• 2017

Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

• 설비공학논문집
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• 제22권12호
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• pp.891-896
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• 2010

The objective of the present study is to reveal the effects of a phase-change material on the performance of a Kimchi refrigerator. Two-percent salt water, of which melting temperature was $-1.1^{\circ}C$, was used for the phase-change material. The salt water was packed in silicon cases and inserted between Kimchi container and the copper pipe of the evaporator. The maximum and minimum temperatures of the inner wall of the Kimchi container without salt-water pack were $-0.2^{\circ}C$ and $-8.9^{\circ}C$, which were remarkably improved by using the salt-water packs, resulting $-0.5^{\circ}C$ and$ -1.9^{\circ}C$. This shows a useful application of using phase-change materials for accurate temperature controls.

• 한국초전도ㆍ저온공학회논문지
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• 제9권2호
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• pp.35-38
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• 2007

A single-stage and two-stage pulse tube refrigerators have been designed for cryopump application. The different diameters of pulse tube and regenerator have been investigated at single-stage pulse tube refrigerator(PTR). Experiments have been performed on single-stage PTR to reach minimum temperature with optimum valve opening at a few frequencies. And the two-stage pulse tube refrigerators have been assembled with tested single-stage pulse tube and tested. When orifice turn is opened to 9 and double inlet is opened to 3 at a single-stage, the lowest temperature of 33.7 K is achieved. The cooling capacity at single-stage is 38 W at temperature of 80 K. A two-stage pulse tube refrigerator has 16.3K at the second stage and 59.7K at the first stage. The cooling capacity achieved is 16.5 W at 80 K, the first stage and 0.6 W at 20 K, the second stage. Some details on the design of pulse tube refrigerator and the experimental apparatus are given.