• 한국포장학회지
• /
• 제27권2호
• /
• pp.91-100
• /
• 2021

Agricultural corrugated fiberboard packaging boxes frequently experience damage due to loading and unloading, vibration during transport, and shock by dynamic distribution condition change. This study was carried out to estimate effect of vibration during distribution process on compression strength of corrugated fiberboard boxes for agricultural products. In order to identify the degradation caused by vibration, after box packaging the agricultural products(tangerine or cucumber), the natural frequencies of the packaging boxes were measured by varying the relative humidity(50, 70 and 90%) at 25℃ temperature. Various types of corrugated fiberboard boxes were packed with tangerines and cucumbers, and the PSD plot vibration tests were conducted by utilizing the actual vibration recording results of the Gyeongbu Expressway section between Seoul and Gimcheon. As a result of the experiment, the decrease in compression strength of the box was relatively low in DW-AB, and the decrease in compression strength of the SW-A 0201(RSC) type box was the highest at 20.49%. In particular, both SW-A and DW-AB showed low compression strength degradation rates for open folder type boxes. The moisture content varies depending on the type of the box or agricultural products, and the enclosed 0201(RSC) type box was generally higher than the open folder or bliss type box, which is believed to be the reason for the decrease in compression strength of RSC type box due to humidity. By the agricultural product, the percentage of decrease in compression strength of box packed with cucumbers was especially high.

• 한국구조물진단유지관리공학회 논문집
• /
• 제13권4호통권56호
• /
• pp.148-158
• /
• 2009

본 연구에서는 강상자형 사교의 윤하중분배계수에 관련된 외국 설계규준들(AASHTO, AASHTO LRFD)의 문제점을 파악하고, 윤하중분배계수에 영향을 미치는 주요변수에 대한 평가를 수행하였다. 또한 다양한 강상자형 사교의 모델에 대한 유한요소해석을 수행하였으며, 그 결과를 바탕으로 회귀분석을 이용하여 강상자형사교의 윤하중분배계수를 산정하는 식을 제안하였다. 본 연구 제안식의 적용 시 기존 설계 규준식의 문제점을 보완할 수 있고, 강상자형사교의 설계시 구조해석에 소요되는 시간을 절약할 수 있어, 그 타당성 및 실용성을 확인할 수 있었다.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
• /
• pp.265-270
• /
• 2007

The potential and step voltage distribution around low voltage joint-box cover were simulated with the variation of resistivity of water, depth of submerged water and point of leakage current. The potential distribution is very high gradient around low voltage joint-box, this condition is very dangerous states.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
• /
• pp.1157-1162
• /
• 2000

Transverse stress and longitudinal crack which are induced by temperature difference in box-girder sections and slab of which box-girder is composed have an important effect on endurance and economical efficiency of bridges. The study on longitudinal behavior of bridges which are subject to thermal load is reflected on the design of bridges. But, the study on transverse behavior of bridges has been performed just recently in foreign countries of finding the cause of longitudinal crack and in Korea, has not been tried in spite of large temperature variance due to geographical condition. This study examines temperature distribution feature in box-girder sections and bridge behavior due to thermal load, with measuring temperature distribution and stress of PSC box-girder bridge which is being constructed actually, and investigates appropriateness of design thermal load of highway bridge design code.

• 한국방재학회 논문집
• /
• 제8권1호
• /
• pp.9-14
• /
• 2008

곡선교의 경우 구조적인 기능이나 미관을 고려하여 강상자형교의 사용이 증가하고 있다. 강상자형교는 비틀림에 대한 강성이 뛰어나고 폐합단면을 가지므로 개단면에 비해 부식에 대해서 유리하며 가설 시에도 안정성을 갖는 장점이 있다. 곡선 강상자형교의 설계는 관용적으로 가로보의 강성을 이용하여 윤하중 횡분배를 유도하는 격자해석으로 실시되고 있다. 본 연구에서는 곡선강상자형교에 대하여 유한요소 해석을 실시하여 곡률, 가로보 및 다이아프램이 윤하중의 횡분배에 미치는 영향에 분석하였다. 해석결과 곡선교에서 곡률은 횡분배에 큰 영향을 미쳤으며 곡률이 증가할수록 분배계수가 증가하는 것을 알 수 있었다. 지점부 다이아프램 외에 지간 중앙에 설치되는 다이아프램 1개는 윤하중의 횡분배와 구조적 안정성에 크게 기여하였으나 추가적인 다이아프램의 설치는 하중의 횡분배에 크게 영향을 주지 못하였다. 콘크리트 슬래브 강성은 가로보에 의한 횡분배 효과보다 크게 나타난 것으로 곡선 강박스교 설계 시에는 콘크리트 슬래브 강성의 횡분배 효과를 고려하여야 할 것이다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 춘계학술대회 논문집
• /
• pp.615-620
• /
• 2005

The purpose of this study was to provide a criterion of ballast aggregate size distribution for paved track. The parameters considered in this study were different types of particle size distribution. Then the analysis for analyzing compressive and flexural strength, physical characteristics of aggregate, and the ballast box test were performed. In the test result of the physical characteristic performed by the ballast box test, the bearing capacity was measured lower than the expected value because of its boundary conditions. Among four types of ballast aggregate, type B was selected as one of best candidate distribution because of its bearing capacity, strength, development and economics.

• The Korean Journal of Ecology
• /
• 제9권4호
• /
• pp.201-208
• /
• 1986

The water status of the leaves of several evergreen plants was investigated in order to discuss the geopgraphical distribution of them. Relastionship between relative water content and water potential of the leaves showed linear decrease for evergreen conifers but exponential decrease for Korean box tree (Buxus microphylla var. koreana). On the basis of the leaf water potential, the water status of the conifers during wintering was distinctly divided into three periods; hardening, cold resistance and dehardening, but lacking in those periods for the Korean box tree, where the status continously decreased. In the cold resistance the leaf water potentials were -23 bar for both spruce (Picea jezoensis) and yew (Taxus cuspidata). From these results and threshold temperature at beginning of hardening, distribution of the conifers was explained that in order of the red pine, the Korean white pine, the yew and the spruce the distribution could be extended at higher altitudes and in more northward areas, whereas the distribution of the Korean box tree was restricted to the lowland of temperate zone.

• 한국강구조학회 논문집
• /
• 제20권1호
• /
• pp.9-20
• /
• 2008

강박스거더교 다이아프램부에 있어서 경제적이고 합리적인 설계가 요망되어 진다. 본 연구에서는 시공중인 4경간 강박스거더교에서 콘크리트 상판 타설 시와 차량재하 시에 응력을 측정한다. 측정 결과는 지점부 다이아프램부와 중앙부에서 응력분배를 연구하기 위하여 분석된다. 다이아프램부 수직보강재의 높이별 응력과 이와 같은 높이의 다이아프램부 응력을 정리하고, 이들 결과를 분석하여 적정 수직보강재 길이의 효율성을 판단한다. 또한 다이아프램부 3조의 수직보강재 각각의 응력을 분석하고, 콘크리트 경화 후 차량 재하 시와 시에 따른 응력비를 산출하여 다이아프램부 설계합리화 연구의 기본 자료로 수립하고자 한다.

• 산업경영시스템학회지
• /
• 제42권2호
• /
• pp.18-27
• /
• 2019

The process control methods based on the statistical analysis apply the analysis method or mathematical model under the assumption that the process characteristic is normally distributed. However, the distribution of data collected by the automatic measurement system in real time is often not followed by normal distribution. As the statistical analysis tools, the process capability index (PCI) has been used a lot as a measure of process capability analysis in the production site. However, PCI has been usually used without checking the normality test for the process data. Even though the normality assumption is violated, if the analysis method under the assumption of the normal distribution is performed, this will be an incorrect result and take a wrong action. When the normality assumption is violated, we can transform the non-normal data into the normal data by using an appropriate normal transformation method. There are various methods of the normal transformation. In this paper, we consider the Box-Cox transformation among them. Hence, the purpose of the study is to expand the analysis method for the multivariate process capability index using Box-Cox transformation. This study proposes the multivariate process capability index to be able to use according to both methodologies whether data is normally distributed or not. Through the computational examples, we compare and discuss the multivariate process capability index between before and after Box-Cox transformation when the process data is not normally distributed.

• Asian Journal of Business Environment
• /
• 제2권1호
• /
• pp.25-34
• /
• 2012

It is possible to use pallet for forwarding as chinese cabbages and radishes are general large-scale trading items at the agricultural wholesale market though, however, most of these are forwarded as it have packed in net bags or in P·E bags. Thus, it is still hard for palletizing. The type of packing the product in the net bag makes it difficult for palletizing. It is not a stable shape enough and easily collapsed for pallet loading. Because of this collapsibility, the corrugated cardboard box is being used to enhance forwarding efficiency, but the existing corrugated cardboard box could be crushed easily by moist what is from the agricultural product's property and it also could be squashed by the mass of the loaded box layers on itself. In contrary, the functional waterproof corrugated cardboard box is not collapsed through palletizing and it is efficient for product management with it's ventilation function in respond to pre-cooling effect. Furthermore, because it has various functional shapes as the open type, the partition type and so on, it is effective for maintaining freshness of the product and standardizing the distribution of agricultural product. It is well-known that it is possible to introduce this box to cargo-works of agricultural product. Consequently, the recognition of main distributors about the pallet distribution of the chinese cabbage and the radish was apprehended in this study for activating mechanization of loading and unloading. The survey was conducted to the main distributors such as the forwarder, the auction dealer and the commission merchant with Garak-dong wholesale market as the center. The appropriate packing materials and problems of the existing method for loading and unloading were derived through the survey. Especially, it was focused on analyzing the difference of recognition between the subject groups for the way of using waterproof cardboard corrugated box to deal with the difficult product for packing in normal corrugated box because of the box's absorption of moist from the agricultural product like a chinese cabbage and a radish. Total In the cases of the forwarders and the commission merchants, the net was highly responded as 45%, 74% from each groups for the best packing material for mechanization of distribution and the waterproof corrugated cardboard box was responded as 20%, 22% from each groups as much preferable than multi-stage wooden box. However, for the radish, the waterproof corrugated cardboard box was the best material as 56%, and the auction trader group supported it for 80%. So, the using the waterproof corrugated cardboard box for mechanization of distribution was negative for the chinese cabbage, but it was positive for the radish. The average was 2.42, the standard deviation was 1.24. The negative response(about 55%) was prevailing more than positive response(about 23%). It could be analyzed that even there was the positive recognition for using the waterproof corrugated cardboard box for the radish though the preference for low price of net bag in the chinese cabbage forwarding procedure. Still now, it seems that is a burden for using the waterproof corrugated cardboard box with high price. In the analysis on the recognition differences about using the waterproof corrugated cardboard box for the chinese cabbages and the radish between the forwarders and the commission merchants, generally the negative recognition was prevailing, but the forwarders(2.696) were more positive for using the waterproof corrugated cardboard box than the commission merchants(2.145).